Models
Goodmanfurnace

GMVC96

ComfortBridge · variable-speed · two-stage · 96% AFUE

Goodman ComfortBridge communicating 96% two-stage. Triple 7-segment IFC, 14-pin serial ECM, optional communicating thermostat with 24V fallback. Badge twin of Amana AMVC96. Dual pressure switches still exist — the display language is ComfortBridge E/b/d, not a 9-speed tap card.

Not GR9T96 / GD9T96 (single 7-seg E0–E9, 9-speed tap motor, conventional 24V only). Not GMEC96 (constant-torque / X-13, no ComfortBridge serial). Not GMSS96 (single-stage LED flash). Not GMVM97 (modulating valve — percent capacity, not two-stage Ht1/Ht2).

Input / AFUE

Up to 96% · two-stage heat

Staging

Two-stage valve · two-speed inducer · dual pressure switches

Blower

Communicating variable-speed ECM (14-pin serial, CFM requested, not taps)

Control

ComfortBridge IFC · triple 7-segment + menu buttons

Tstat

ComfortBridge / communicating preferred · 24V W1/W2 fallback

Shared data

Memory card on the IFC stores cabinet size / motor tables — move it with the board

Sister SKU

Amana AMVC96 · GMVM97 is the modulating cousin

This board

ComfortBridge IFC · three 7-segment digits + menu buttons

  • Three digits, not one. Status words (idle, Ht1, Ht2, CF, CL1) are not faults.
  • Faults are letter+digit: E0–E9 / EA / EE for heat/prove, b0–b9 for the serial ECM, d0/d4 for the shared-data card.
  • Learn / menu buttons step through CFM, heat staging, and last faults. Do not treat a setup screen as a lockout.
  • Read the door card on THIS revision — ComfortBridge menus moved between board generations.
  • A communicating outdoor on the same bus changes what a ‘no Y’ complaint means — the IFC may be the thermostat.

Use the IFC menu (not the GR9T96 2-second hold) to read fault history. Write the exact three characters plus any decimal. Power cycle clears live status, not always the stored stack.

Universal swap

No universal

No universal. Communicating ComfortBridge — factory twin of AMVC96.

Silk: GMVC96 · ComfortBridge

White-Rodgers

ICM

Honeywell

  • Any 50A55-843 / 50A65-843 / 50M56U-843 / 50M56X-843 / S9200U1000 universal — those are conventional 24V HSI, not this data bus.
  • ICM280 / 2811 / 2810 / 282B — wrong IFC family.
  • GR9T96 PCBBF132. GMSS96 LED board.

After you pull the dead card

  1. 1OEM ComfortBridge IFC. CoolCloud. Do not drop a 9-speed tap board into this cabinet.

Field wiring

Written landings for Goodman GMVC96. Not a factory schematic.

ComfortBridge / ComfortNet furnace
1 / 2 data — or 24VGas furnace

Goodman / Amana / Daikin communicating two-stage. Outdoor on 1 and 2 when the outdoor talks. A 24V GSX16 still wants Y, not data.

Written circuit description only — FieldBench does not redraw maker schematics. Example: R to W closes on a heat call; verify 24V at W1 before you change the IFC.

Open manufacturer PDF

Heat sequence

  1. 1Power. L1 / N → IFC120V
  2. 2Call. Data pair or 24V W → IFCBus or 24V
  3. 3Draft. IFC → inducer → proveTwo-stage PS or a pressure band
  4. 4Ignite. IFC → HSI → valve120V igniter
  5. 5Blow. IFC → serial ECMNo tap, no cap

This indoor

ComfortBridge 96%. GSXC/GXV on 1/2. GSX16 on Y.

Communicating outdoor

GSXC / ASXC / GXV / DZ / FIT on the same bus. CoolCloud or Daikin One at the wall.

CoolCloud / Daikin One

Menus on the indoor. Do not put R/C on 1 and 2.

  • 1DataData
  • 2DataData

ComfortBridge / ComfortNet IFC

Memory card must match THIS cabinet (ARVT96 card is not AMVC96).

  • 1Data to outdoorData
  • 2Data to outdoorData
  • R24V accessories24V
  • CCommon24V

Landing

  • DataIFC 1outdoor 1 · IFC 2outdoor 2

    Data. Polarity matters.

24V outdoor on this IFC

GSX16 / GLXS4B / any contactor outdoor. Land Y. Leave 1/2 empty.

Conventional stat (allowed)

W1/W2/Y/G on the IFC 24V strip. Not on 1/2.

  • RHot24V
  • CCommon24V
  • W1Heat24V
  • YCool24V
  • GFan24V

Landing

  • 24VStat YIFC Youtdoor Y

    ~24 VAC. Data wire is a miswire.

IFC harness — communicating two-stage

Call arrives on the data pair (or 24V W). Gas train is still inducer / prove / igniter / valve.

Transformer + fuse

24V still exists for accessories and for a 24V outdoor. Data pair is not the transformer.

  • L1 / N120VLine
  • R / C24V strip24V
  • FUSEOn the IFC24V

24V safety chain

Limit / rollout / door still open the heat path. Codes are on THIS IFC language.

  • DOORInterlock24V
  • LIMITMain limit24V
  • ROLLOUTManual reset24V

Two-speed inducer + dual PS

Low vs high prove. Do not tee the hoses. Do not apply this to a modulating cousin.

  • IND LO/HITwo-speed inducerLine
  • LPSLow prove24V
  • HPSHigh prove24V

HSI + two-stage valve

Two solenoids or a two-stage valve. Staging is the bus or W1/W2, not a tap.

  • HSI120V igniterLine
  • MV / HV24V low / high solenoids24V
  • FLAMEµA DC24V

Serial variable-speed ECM

IFC talks to the motor on the serial harness. No F-taps. No dual run cap on this blower.

  • SERIALIFC-to-motor harness. Unplugged motor = CFM / comm fault, not a tap problem24V
  • CFMSet in the IFC menu / model plug / CoolCloud — not a dip switch on most of these24V

Landing

  • LineCallIFCinducerprove

    Low then high

  • LineIFCHSIvalve

    120V igniter, 24V or serial valve

  • 24VFlame rodIFC

    µA DC

  • DataIFCserial blower

    No F-taps. No PSC cap.

Prove it

  • Indoor family first. Communicating outdoor = 1/2. Contactor outdoor = Y.
  • Memory card / CoolCloud sees THIS furnace.

Do not

  • Do not drop an ARVT96 card into AMVC96 or the other way around.
  • Do not land 1/2 on a GR9T96.

1 and 2 are the published ComfortBridge / ComfortNet pair.

Sequence

  1. 1

    Call

    Communicating tstat requests heat capacity. On 24V fallback, W1/W2 behave like a two-stage furnace but CFM still comes from the IFC tables — there are no heat taps.

  2. 2

    Inducer / low PS

    Inducer on low. Low-fire PS must close. Already closed with inducer off → E1. Never closes → E2. Same physics as GR9T96, ComfortBridge presentation.

  3. 3

    HSI / low-fire valve

    Nitride warm-up, first-stage solenoid. Failures stack to E0 after 3 retries. Open igniter / ground → E7.

  4. 4

    Blower

    Serial ECM ramps to the IFC heat CFM. A tap jumper from a GR9T96 or a CT plug from a GMEC96 will not run this motor.

  5. 5

    W2 / high fire

    Inducer goes high (or the communicating request raises capacity). High-fire PS must close (E9 if open, E8 if it was already closed). Second solenoid opens.

  6. 6

    Satisfied

    Valve off, post-purge, blower delay. Unexpected flame → E4.

Faults on this IFC

Step 1, then 2, then 3. Expected reading and the fail branch sit under each check.

idle / Ht1 / Ht2 / CF / CL1

Status, not a fault

info

Normal run states on the triple display. idle = standby, Ht1/Ht2 = low/high heat, CF = continuous fan, CL1 = low cool.

  1. 1 Confirm this is not a fault

    On the Goodman GMVC96 this readout (idle / Ht1 / Ht2 / CF / CL1) is run status, not a lockout. Write what the display actually shows and whether W/Y/G is present at the IFC.

    Expect: Idle / Ht / CF / stage+CFM words change when you apply and remove the call.

    If fail: If the word never changes on a real call, the call is not reaching this IFC.

    If pass: The board is alive. Diagnose the comfort complaint, not this code.

  2. 2 Prove the call at the board

    Measure R to W / Y / G at the Goodman GMVC96 IFC, not at the thermostat. Communicating plates need the data pair and a live indoor address — 24 V on W is not the test.

    Expect: Do not replace the board because it says Ht1 or idle.

    If fail: Fix the stat, harness, or data pair before you change parts.

  3. 3 Watch one full sequence

    Leave power on. Watch ComfortBridge IFC · three 7-segment digits + menu buttons through one cycle and write the first real fault that replaces this status word.

    Expect: Call: Communicating tstat requests heat capacity. On 24V fallback, W1/W2 behave like a two-stage furnace but CFM still comes from the IFC tables — there are no heat taps.

E0

Retry lockout (3 retries)

lockout

Ignition or recycle limit on this call. Three failed tries and the IFC sits.

  1. 1 Airflow before you touch the limit

    On Goodman GMVC96 a limit is airflow or overfire until proven otherwise. Do not replace the limit first. Filter, blower wheel, A-coil, and the heat-speed setting for THIS motor (tap, model plug, or communicating CFM — not a sister SKU chart). Watch one full try: inducer, HSI, valve, flame, µA. Which step dies?

    Expect: Rise in the rating-plate window. Static vs this cabinet’s blower chart.

  2. 2 Measure static and temperature rise

    Total external static vs the Goodman GMVC96 blower chart for this cabinet size. Supply minus return rise after 8–10 minutes. A new 5" media cabinet or closed supplies will trip this all winter. Gas supply and manifold low then high.

    Expect: Rise typically 35–65 °F — rating plate wins.

    If fail: Fix the restriction or the heat-speed setting. The limit is doing its job.

    If pass: Airflow in range → step 3 (overfire / limit itself).

  3. 3 Overfire, then the limit circuit

    Clock the meter / manifold on the stage that is tripping vs the rating plate. Then ohm the limit after it cools — a limit that never recloses is failed. Rollout in the same circuit is a different call (see rollout on this door card). Do not keep resetting the hour — find the failed step.

    Expect: Manifold on plate. Limit closed when cool.

E1

Low-fire PS stuck closed

lockout

Low-stage pressure switch is made with the inducer off.

  1. 1 Unplug the switch with the inducer off

    On Goodman GMVC96 this code is the switch made when the inducer is not running. Unplug that switch only. Unplug the LPS. Code change = welded switch or water in the hose.

    Expect: Code changes when the harness is open.

    If fail: Wrong switch, or the IFC input is shorted.

    If pass: Switch/hose path. Go to step 2.

  2. 2 Water in the hose vs a welded switch

    Blow the hose. Water holding residual draft is more common than a welded switch. Confirm the hose is not teed and not routed uphill. Ohm the switch with the hose off. Same collector-hose physics as GR9T96 E1. Communicating does not fix a drowned trap.

    Expect: Hose empty. Switch opens with no draft.

  3. 3 IFC input last

    If the switch ohms open, the hose is dry, and the code does not change with the harness off, the Goodman GMVC96 IFC input is shorted. Do not keep swapping switches.

    Expect: Known-good open switch + open harness = code gone. If not, IFC.

E2

Low-fire PS open

lockout

Inducer on low, low-fire switch will not close.

  1. 1 Prove inducer and the live code

    Do not pull power — that clears the Goodman GMVC96 active code. Write E2. Is the inducer spinning on this call? Silent inducer is not a pressure switch. Inducer 120 VAC and spinning on the heat call.

    Expect: 120 VAC at the inducer on a heat call. Wheel turning.

    If fail: 120 VAC missing → IFC / door switch / incoming power. Voltage + dead motor → inducer.

    If pass: Inducer running + this code → trap, hose, switch, vent (step 2).

  2. 2 Trap, collector, and the hose

    A drowned 96% trap will not make collector pressure. Pull the trap, flush it, confirm the collector box and inducer outlet are not full. Hose cracked, off the port, or full of water fakes an open switch. Trap, collector, PVC intake/exhaust, LPS hose on the low tap.

    Expect: Trap flowing, hose dry and downhill, ports not swapped on a two-switch board.

  3. 3 Switch ohms, then vent load

    Ohm the pressure switch: NO, must close when that inducer speed is making the collector setpoint. If the switch is good, walk the PVC — bird screen, ice, long 2" run, wind, shared chase. Shared-data / CFM settings do not create draft. Fix the vent path.

    Expect: LPS / HPS: Both NO. Closed only when that inducer speed is making the collector setpoint.

    If fail: Replace the open switch only after the vent and trap are proven.

    If pass: Switch closes on draft and the code stays → IFC input.

E3

Limit / rollout

warn

Primary limit or rollout string opened. VS motor should have been ramping — if the limit still opens, static or overfire. Rollout in this string is still a flame-containment hazard.

  1. 1 Treat this as flame outside the exchanger

    Do not reset the Goodman GMVC96 rollout and walk away. Write the code, kill the call, and look for flame at the burners, crossover, and vestibule before you do anything else.

    Expect: No flame outside the exchanger. Burners seated. Crossover lit.

    If pass: Still inspect secondary / flue / condensate before you reset.

  2. 2 Secondary, condensate, and flue

    Blocked secondary, drowned collector, or a plugged flue pushes flame out the front. Pull the inducer/collector look, confirm the trap is flowing, and check PVC/vent. IFC heat CFM setting, not a 9-speed tap. Filter, coil, return size. Which switch in the string is open? Limit = airflow. Rollout = exchanger / burners / flue — manual reset, treat as hazard.

    Expect: Dry collector, open flue, trap clear.

  3. 3 Reset only after the cause is fixed

    Manual-reset rollout. Recurring rollout on Goodman GMVC96 is a CO / fire call — cracked primary, misaligned burners, or a failed secondary. Confirm CO in the space before you leave. Manifold vs plate. Overfire trips limits with a clean filter.

    Expect: One clean cycle after the cause is fixed. No second reset as a repair.

E4

Unexpected flame

hazard

Rod sees flame with both solenoids de-energized.

  1. 1 Shut the gas cock first

    On Goodman GMVC96 the rod sees flame with the valve de-energized. Shut the cock. If flame stays, the valve is leaking — replace it. Do not jump or energize it as a test. Shut the gas cock. If flame stays, leaking valve — replace, do not jump.

    Expect: Flame dies when the cock is shut.

    If fail: Leaking valve. Replace. Do not leave the unit.

  2. 2 Rod and IFC flame circuit

    If flame dies with the cock shut, the rod is shorted to ground or the IFC flame circuit is lying. Unplug the rod, inspect ceramic, and check the harness for a rub-through on the collector. Rod shorted to ground or IFC flame circuit.

    Expect: Rod isolated from ground. IFC does not report flame with the rod unplugged.

  3. 3 Confirm valve solenoids are actually off

    Measure 24 VAC at both solenoids after the call drops. A welded IFC relay or a shorted W will keep a solenoid wet and look like ‘unexpected flame.’ Replace the IFC only after the valve and rod are proven.

    Expect: 0 VAC at both solenoids after the call. No flame.

E5

Open fuse

warn

IFC automotive fuse is open.

  1. 1 Find the 24 V short before you replace the fuse

    On Goodman GMVC96 an open IFC fuse is a short on W, Y, G, HUM, EAC, or a data pair landed on 24 V. Unplug the thermostat / data harness first. 24 V short on W, Y, G, humidifier, EAC, or leftover ComfortBridge data landed on 24V.

    Expect: Fuse out. 24 V transformer still good. Harness isolated.

  2. 2 Replace the fuse with the harness off

    New fuse, harness still off. If it holds, the short is in the field wiring or accessory. Plug one circuit back at a time (W, then Y, then HUM/EAC). Unplug tstat / data harness and replace fuse. If it blows again the short is on the board or valve harness.

    Expect: Fuse holds with harness off. Dies when the shorted lead lands.

  3. 3 If it blows with the harness off

    Short is on the Goodman GMVC96 IFC or the gas-valve harness. Unplug the valve and try once more. Repeat blow with valve unplugged = IFC.

    Expect: Do not keep feeding fuses into a welded valve coil or a burned IFC trace.

E6

Low flame signal

warn

Flame present, µA below the IFC threshold.

  1. 1 Measure µA while it is running

    Do not clean first and guess. Series-µA the rod on Goodman GMVC96 during a call. Falling µA is oxide, ground, or a dying flame. A hard drop is often the pressure switch or limit opening, not the rod. Clean rod with a non-scratch pad.

    Expect: Flame rod: µA per this IFC sticker, not the GR9T96 door card.

  2. 2 Rod, ground, then gas

    Clean the rod with a non-scratch pad — not sandpaper. Chassis ground to burner box and IFC (painted screw and missing star washer are classic). Then manifold on the stage that is dropping and confirm LP conversion leftovers. Chassis ground to burner box and IFC.

    Expect: Manifold on the rating plate. Solid burner-box ground.

  3. 3 Prove it is not a switch opening

    Watch the live Goodman GMVC96 display when flame drops. A PS or limit code that appears at the drop means the rod was a victim. Inducer, hose, vent wind, or a limit on a wrong heat tap. Manifold / orifice / LP conversion.

    Expect: µA stable and the live code stays a flame code — then rod/valve/IFC. Otherwise chase the new code.

E7

Igniter / ground

lockout

Igniter circuit or flame-sense ground did not behave as commanded.

  1. 1 Ohms at the igniter, then at the IFC

    On Goodman GMVC96 measure cold ohms at the igniter plug, then at the IFC connector. An open at the plug is the element or local harness. Open only at the IFC is the harness rub-through on the collector. Igniter ohms cold and 120 VAC during warm-up.

    Expect: Nitride cold ohms per THIS door sticker — do not use an 80% Norton chart.

  2. 2 120 VAC during warm-up

    Call for heat and measure 120 VAC at the igniter during the warm-up window. 0 V + good ohms = IFC igniter relay. Voltage + no glow = cracked nitride. Cracked nitride. Burner-box ground screw (paint, missing star washer).

    Expect: 120 VAC only during warm-up. Visible glow before the valve opens.

  3. 3 Do not keep cycling a cracked element

    A cracked nitride can ohm ‘good’ cold and open hot. If ohms and voltage are good and there is no glow, replace the igniter. Confirm polarity/ground (this plate’s polarity code) before you condemn a new igniter. Do not confuse with b0 — E7 is HSI/ground, b0 is the indoor blower.

    Expect: One clean light after a known-good igniter and a proven ground.

E8

High-fire PS stuck closed

lockout

High-stage pressure switch is made with the inducer not on high.

  1. 1 Prove the switch is made with inducer not on high

    On Goodman GMVC96 this code means the high-fire switch is closed when it should be open. Do not treat it as the low-fire stuck-closed code. Write the live display, then unplug the high-fire switch only.

    Expect: Code should change when the high-fire harness is open.

    If fail: IFC input shorted or you unplugged the wrong switch.

  2. 2 Hose water and a welded switch

    Water in the high-fire hose holds residual draft and fakes a closed switch. Route downhill to the collector. Ohm the switch with the hose off — a welded high-fire switch stays closed. Second switch — do not treat as E1. Welded HPS or water-filled hose.

    Expect: Hose dry. Switch opens with no draft.

  3. 3 Confirm the IFC is not commanding high

    W2 shorted to W1, a communicating stat stuck on high, or an IFC that never drops inducer speed will keep this code alive. Measure W2 at the board and watch inducer speed after you open the high-fire harness. W2 shorted to W1 on 24V fallback.

    Expect: Inducer on low (or off) with W2 open. High-fire switch ohms open.

E9

High-fire PS open

lockout

Inducer on high, high-fire switch never closes. Runs on low, will not go high.

  1. 1 Prove the high-fire call

    Write the live Goodman GMVC96 code before you pull power. Confirm this IFC is actually commanded to high — W2 at the board, or the staging timer has expired. Does the inducer actually change speed on the high-stage request?

    Expect: R to W2 ~24 VAC (conventional) or a high-stage request on a communicating stat.

    If fail: No high request → thermostat / staging / menu. Not a high-fire pressure switch.

    If pass: Go to step 2. Do not jump the high-fire switch to ‘see if it runs.’

  2. 2 Prove the inducer actually went high

    Listen and amp the inducer on low vs high. No speed-up → IFC high output or inducer winding. Speed-up and this code still live → high-fire PS path (hose, switch, vent). HPS hose on the high tap only — never teed to the LPS.

    Expect: LPS / HPS: Both NO. Closed only when that inducer speed is making the collector setpoint.

    If fail: Measure 120 VAC on the high-speed inducer lead during the high call. 0 V = IFC. Voltage + dead motor = inducer.

  3. 3 Isolate the HIGH hose and switch

    High-fire hose on the high tap only — a tee with the low switch is the common first-install miss on this dual-switch plate. Blow the hose, confirm it is dry and downhill to the collector. Ohm the high-fire switch: it is NO and must close only on high draft. Vent capacity on 100–120 kBtu cabinets. High fire needs more draft than E2 ever saw.

    Expect: LPS / HPS: Both NO. Closed only when that inducer speed is making the collector setpoint.

    If fail: Welded open, cracked hose, or water in the line. Replace the failed part — do not leave a jumper.

    If pass: Switch and hose good → step 4 (vent / condensate / IFC).

  4. 4 Vent, condensate, and the IFC input

    High fire needs more draft than a low-fire code ever saw. Check PVC size on this cabinet, shared chase, wind, ice, bird screen, and condensate backing into the collector only on high. If the switch closes on known draft and the code stays, the Goodman GMVC96 IFC input is the last call.

    Expect: Clear vent, dry collector, known-good switch, then IFC.

EA

Line polarity / ground

lockout

L1/N reversed or chassis ground missing. HSI and flame sense both suffer.

  1. 1 Measure µA while it is running

    Do not clean first and guess. Series-µA the rod on Goodman GMVC96 during a call. Falling µA is oxide, ground, or a dying flame. A hard drop is often the pressure switch or limit opening, not the rod. Hot and neutral at the IFC, not just the disconnect.

    Expect: Flame rod: µA per this IFC sticker, not the GR9T96 door card.

  2. 2 Rod, ground, then gas

    Clean the rod with a non-scratch pad — not sandpaper. Chassis ground to burner box and IFC (painted screw and missing star washer are classic). Then manifold on the stage that is dropping and confirm LP conversion leftovers. Burner box to IFC ground screw.

    Expect: Manifold on the rating plate. Solid burner-box ground.

  3. 3 Prove it is not a switch opening

    Watch the live Goodman GMVC96 display when flame drops. A PS or limit code that appears at the drop means the rod was a victim. Inducer, hose, vent wind, or a limit on a wrong heat tap.

    Expect: µA stable and the live code stays a flame code — then rod/valve/IFC. Otherwise chase the new code.

EE

No 115V / internal

lockout

IFC lost line voltage or failed an internal power/self-check. This is not a ComfortBridge data-pair code.

  1. 1 Measure at the IFC under load

    On Goodman GMVC96 line-voltage codes are incoming power. Measure L1/L2 (or L1/N) at the board while it is trying to run, not just at the disconnect. L1/N at the IFC, door switch, incoming 120 VAC under load.

    Expect: Voltage in the rating-plate window under load.

  2. 2 Drop, breaker, and the whip

    Large drop from the disconnect to the IFC is a loose lug or damaged whip. Breaker that will not hold under inducer/blower start is the circuit, not the board. Transformer 24 VAC secondary. Internal IFC failure only after line power is proven.

    Expect: Minimal drop. Tight lugs. Correct breaker size.

  3. 3 Transformer 24 V last

    If line is good and 24 V is low, load the transformer (stat + valve + accessories). A collapsing 24 V looks like a comm or fuse call. Do not chase a data pair because an older note called EE ‘bus.’ On this chart EE is power/internal.

    Expect: 24 V holds under load. Line stays in window.

b0

ECM not running

lockout

IFC commanded the serial blower and it did not run.

  1. 1 Reseat the serial plug

    On Goodman GMVC96 this is a communicating / serial ECM, not a tap motor. Kill power, reseat the 14-pin (or OEM serial plug) at the motor and at the IFC. Pins straight, no corrosion. 14-pin harness fully seated at motor and IFC. No tap plugs on this motor.

    Expect: Plug fully seated both ends. Correct motor for this cabinet.

  2. 2 Power and the data pair at the motor

    Line voltage at the motor, then the serial/data pair continuity. A half-seated plug or a pinched harness throws comm on a good motor. Line voltage at the motor, wheel free, no water in the winding.

    Expect: Line voltage present. Data pair not shorted to chassis.

  3. 3 Motor vs IFC serial driver

    Known-good motor still throws this code = Goodman GMVC96 IFC serial driver. Known-good IFC still throws it = motor module. Do not put a PSC or 9-speed tap motor on a serial IFC. Wrong motor (9-speed or CT) in this cabinet will sit here forever.

    Expect: One clean CFM request after a known-good pair.

b1

ECM comms lost

lockout

Serial link between IFC and indoor blower dropped after the motor was seen.

  1. 1 Reseat the serial plug

    On Goodman GMVC96 this is a communicating / serial ECM, not a tap motor. Kill power, reseat the 14-pin (or OEM serial plug) at the motor and at the IFC. Pins straight, no corrosion. Harness continuity and pin tension on the 14-pin. Rub-through at the blower deck.

    Expect: Plug fully seated both ends. Correct motor for this cabinet.

  2. 2 Power and the data pair at the motor

    Line voltage at the motor, then the serial/data pair continuity. A half-seated plug or a pinched harness throws comm on a good motor. Motor control module vs IFC — reseat both before you replace both.

    Expect: Line voltage present. Data pair not shorted to chassis.

  3. 3 Motor vs IFC serial driver

    Known-good motor still throws this code = Goodman GMVC96 IFC serial driver. Known-good IFC still throws it = motor module. Do not put a PSC or 9-speed tap motor on a serial IFC. This is motor serial, not the ComfortBridge thermostat data pair.

    Expect: One clean CFM request after a known-good pair.

b2

HP mismatch vs shared data

lockout

Motor horsepower does not match what the memory card / shared data says this cabinet is.

  1. 1 Read the plug / card on THIS cabinet

    On Goodman GMVC96 the model plug or shared-data card must match this cabinet size. A 100 kBtu plug in an 80 cabinet overfires and limits. A leftover memory card after a control swap throws d0/d4-class codes. Compare motor HP stamp to the furnace model and the shared-data card.

    Expect: Plug / card part matches the rating plate and the replacement control bulletin.

  2. 2 Reseat, then confirm the menu

    Kill power, reseat, restore power. On communicating plates open the setup and confirm unit size / motor HP. After an IFC or motor swap, the card from the old board must travel with the cabinet size.

    Expect: IFC recognizes the plug. No size-mismatch code.

  3. 3 Do not run it mismatched

    A wrong plug is not a ‘temporary’ fix. It will throw limit, ignition, or blower-band codes that look like bad parts. Fit the correct plug, then re-run the original complaint. A ¾ HP motor in a 1 HP cabinet (or the reverse) throws b2 even when the wheel spins.

    Expect: One clean sequence on the correct identity.

b3

Motor limiting

warn

ECM is folding back current / torque — usually static, not a dead motor.

  1. 1 Airflow before you touch the limit

    On Goodman GMVC96 a limit is airflow or overfire until proven otherwise. Do not replace the limit first. Filter, blower wheel, A-coil, and the heat-speed setting for THIS motor (tap, model plug, or communicating CFM — not a sister SKU chart). Total external static vs the GMVC96 blower chart. Media cabinet + dirty coil is the usual.

    Expect: Rise in the rating-plate window. Static vs this cabinet’s blower chart.

  2. 2 Measure static and temperature rise

    Total external static vs the Goodman GMVC96 blower chart for this cabinet size. Supply minus return rise after 8–10 minutes. A new 5" media cabinet or closed supplies will trip this all winter. IFC cool/heat CFM set higher than the duct can take.

    Expect: Rise typically 35–65 °F — rating plate wins.

    If fail: Fix the restriction or the heat-speed setting. The limit is doing its job.

    If pass: Airflow in range → step 3 (overfire / limit itself).

  3. 3 Overfire, then the limit circuit

    Clock the meter / manifold on the stage that is tripping vs the rating plate. Then ohm the limit after it cools — a limit that never recloses is failed. Rollout in the same circuit is a different call (see rollout on this door card). Wheel rub or restriction that is not quite a lock.

    Expect: Manifold on plate. Limit closed when cool.

b4

Trip / lost rotor

lockout

Motor tripped or lost rotor position while running.

  1. 1 Is the wheel free?

    Spin the Goodman GMVC96 blower by hand. Ice, debris, or a seized bearing is not a control problem. Confirm the motor type on this plate — serial ECM, 9-speed tap, or X-13 — before you grab a capacitor. Wheel interference, wet winding, failing module.

    Expect: Wheel free. Correct motor family for this IFC.

  2. 2 Command vs rotation

    Call for G or heat and confirm the IFC is actually requesting CFM (taps, serial, or communicating). Amp the motor. Locked rotor + a good command = motor. No command = IFC / harness / shared data. Line voltage sag at the motor during ramp.

    Expect: Command present. Motor amps in range, not locked.

  3. 3 Static and the wrong motor

    High static will trip current/limit codes and look like a dead motor. Measure TES vs this cabinet. Wrong horsepower or a leftover memory card after a control swap is the other half of this call. Replace motor only after harness and static are clean.

    Expect: Static on the blower chart. Matching motor / shared-data card.

b5

Locked rotor

lockout

Blower cannot turn.

  1. 1 Is the wheel free?

    Spin the Goodman GMVC96 blower by hand. Ice, debris, or a seized bearing is not a control problem. Confirm the motor type on this plate — serial ECM, 9-speed tap, or X-13 — before you grab a capacitor. Spin the wheel by hand. Ice, debris, seized bearing.

    Expect: Wheel free. Correct motor family for this IFC.

  2. 2 Command vs rotation

    Call for G or heat and confirm the IFC is actually requesting CFM (taps, serial, or communicating). Amp the motor. Locked rotor + a good command = motor. No command = IFC / harness / shared data. Capacitor is not the play — this is a serial ECM.

    Expect: Command present. Motor amps in range, not locked.

  3. 3 Static and the wrong motor

    High static will trip current/limit codes and look like a dead motor. Measure TES vs this cabinet. Wrong horsepower or a leftover memory card after a control swap is the other half of this call.

    Expect: Static on the blower chart. Matching motor / shared-data card.

b7

Motor parameters

lockout

IFC rejected the motor’s reported parameters vs shared data.

  1. 1 Read the plug / card on THIS cabinet

    On Goodman GMVC96 the model plug or shared-data card must match this cabinet size. A 100 kBtu plug in an 80 cabinet overfires and limits. A leftover memory card after a control swap throws d0/d4-class codes. Motor is the OEM serial ECM for this cabinet — not a ‘close’ aftermarket that talks a different table.

    Expect: Plug / card part matches the rating plate and the replacement control bulletin.

  2. 2 Reseat, then confirm the menu

    Kill power, reseat, restore power. On communicating plates open the setup and confirm unit size / motor HP. Shared-data card present and for this model family.

    Expect: IFC recognizes the plug. No size-mismatch code.

  3. 3 Do not run it mismatched

    A wrong plug is not a ‘temporary’ fix. It will throw limit, ignition, or blower-band codes that look like bad parts. Fit the correct plug, then re-run the original complaint. Reflash / card reseat before condemning a new motor.

    Expect: One clean sequence on the correct identity.

b9

Low airflow

warn

Delivered CFM well below the request. Duct or restriction, not an ignition code.

  1. 1 Watch one full try — do not reset

    Write the Goodman GMVC96 code. Watch inducer, HSI glow, valve click, flame, µA. The step that dies is the repair. Resetting only burns another try into a harder lockout. Filter, coil, closed returns, crushed flex.

    Expect: Call → Inducer / low PS → HSI / low-fire valve → Blower → W2 / high fire → Satisfied

  2. 2 Gas and the valve

    Cock open, inlet pressure, then manifold on the stage that is failing vs the rating plate. 24 VAC at the valve during trial? Coil ohms? A valve that never opens looks like a ‘bad igniter’ if you did not watch the sequence. IFC CFM vs actual TES. b3 often rides along.

    Expect: Inlet and manifold on the plate. 24 VAC only during trial.

  3. 3 Flame prove, then the lockout timer

    Glow + valve + no prove → rod, ground, or IFC sense. Prove then drop → µA / PS / limit. Soft lockouts on this family often auto-reset on a long clock — do not sit on resets. Do not raise heat CFM into a brick to ‘fix’ b9.

    Expect: Flame rod: µA per this IFC sticker, not the GR9T96 door card.

d0

No shared data / missing memory card

lockout

IFC cannot read the furnace identity card. Classic after an IFC swap when the card stayed on the old board or in the box.

  1. 1 Read the plug / card on THIS cabinet

    On Goodman GMVC96 the model plug or shared-data card must match this cabinet size. A 100 kBtu plug in an 80 cabinet overfires and limits. A leftover memory card after a control swap throws d0/d4-class codes. Look at the small memory / shared-data card on the IFC. It must be present and seated.

    Expect: Plug / card part matches the rating plate and the replacement control bulletin.

  2. 2 Reseat, then confirm the menu

    Kill power, reseat, restore power. On communicating plates open the setup and confirm unit size / motor HP. Move the card from the failed IFC onto the replacement — that card is the cabinet.

    Expect: IFC recognizes the plug. No size-mismatch code.

  3. 3 Do not run it mismatched

    A wrong plug is not a ‘temporary’ fix. It will throw limit, ignition, or blower-band codes that look like bad parts. Fit the correct plug, then re-run the original complaint. A blank replacement board with no card will not run this furnace. Do not ‘program around it’ with GR9T96 taps.

    Expect: One clean sequence on the correct identity.

d4

Invalid memory card

lockout

Card is present but the data is corrupt, wrong family, or unreadable.

  1. 1 Read the plug / card on THIS cabinet

    On Goodman GMVC96 the model plug or shared-data card must match this cabinet size. A 100 kBtu plug in an 80 cabinet overfires and limits. A leftover memory card after a control swap throws d0/d4-class codes. Card from a GMVM97, GMEC, or a different tonnage will read invalid on this IFC.

    Expect: Plug / card part matches the rating plate and the replacement control bulletin.

  2. 2 Reseat, then confirm the menu

    Kill power, reseat, restore power. On communicating plates open the setup and confirm unit size / motor HP. Reseat. If it still d4s, OEM card for this exact GMVC96 size — not a generic ‘ComfortBridge card.’

    Expect: IFC recognizes the plug. No size-mismatch code.

  3. 3 Do not run it mismatched

    A wrong plug is not a ‘temporary’ fix. It will throw limit, ignition, or blower-band codes that look like bad parts. Fit the correct plug, then re-run the original complaint. Do not mix Amana AMVM97 modulating cards into a two-stage GMVC96.

    Expect: One clean sequence on the correct identity.

Workflows

Identify vs GR9T96

First minute on site. Data plate dirty or the last tech mixed boards.

  1. 1 Prove the call and the live code

    14-pin serial motor plug + triple 7-seg with menu buttons = stay on GMVC96.

    Expect: Write whatever ComfortBridge IFC · three 7-segment digits + menu buttons is showing. Use the IFC menu (not the GR9T96 2-second hold) to read fault history. Write the exact three characters plus any decimal. Power cycle clears live status, not always the stored stack.

    If fail: No call at the IFC → stat / harness. Do not change gas parts.

  2. 2 Isolate the first failed step in the sequence

    Single 7-seg and a 9-speed tap harness (no 14-pin serial) = GR9T96. Leave this page.

    Expect: Inducer / low PS: Inducer on low. Low-fire PS must close. Already closed with inducer off → E1. Never closes → E2. Same physics as GR9T96, ComfortBridge presentation.

  3. 3 Confirm with a number, then the next part

    CT / X-13 style 5-wire profile plug, two-stage, 7-seg E0–E9, no ComfortBridge menu = GMEC96. One pressure switch and a flashing LED = GMSS96. Do not install a GR9T96 9-speed motor as a ‘cheaper ECM’ in this cabinet.

    Expect: Data pair: OEM communicating voltage / polarity — never 24 VAC between the data pins. · Motor harness: 14-pin serial ECM, fully seated. No tap plugs. No CT profile harness.

    If fail: Stay on this plate. The out-of-range reading is the part.

    If pass: Reading in range → the next step in this workflow is the repair.

b0 / b1 motor

Heat or cool call, blower silent or dropping, b0 or b1 on the triple display.

  1. 1 Prove the call and the live code

    Photograph the three characters. b0 = never ran. b1 = ran and the serial link died.

    Expect: Write whatever ComfortBridge IFC · three 7-segment digits + menu buttons is showing. Use the IFC menu (not the GR9T96 2-second hold) to read fault history. Write the exact three characters plus any decimal. Power cycle clears live status, not always the stored stack.

    If fail: No call at the IFC → stat / harness. Do not change gas parts.

  2. 2 Isolate the first failed step in the sequence

    Reseat the 14-pin at motor and IFC. Look for rub-through at the blower rail.

    Expect: Inducer / low PS: Inducer on low. Low-fire PS must close. Already closed with inducer off → E1. Never closes → E2. Same physics as GR9T96, ComfortBridge presentation.

  3. 3 Confirm with a number, then the next part

    Line voltage at the motor. Wheel free? Water in the end bell? If a 9-speed or CT motor is in this housing, stop — that is the fault. b2/b7 after a motor change: HP and shared-data card must match the cabinet. The new motor is not ‘plug and play’ across sizes.

    Expect: Data pair: OEM communicating voltage / polarity — never 24 VAC between the data pins. · Motor harness: 14-pin serial ECM, fully seated. No tap plugs. No CT profile harness.

    If fail: Stay on this plate. The out-of-range reading is the part.

    If pass: Reading in range → the next step in this workflow is the repair.

d0 after IFC swap

New board, furnace will not configure, d0 or d4.

  1. 1 Prove the call and the live code

    The memory / shared-data card from the old IFC must move to the new one. That card is the furnace model.

    Expect: Write whatever ComfortBridge IFC · three 7-segment digits + menu buttons is showing. Use the IFC menu (not the GR9T96 2-second hold) to read fault history. Write the exact three characters plus any decimal. Power cycle clears live status, not always the stored stack.

    If fail: No call at the IFC → stat / harness. Do not change gas parts.

  2. 2 Isolate the first failed step in the sequence

    d0 = card missing. Look in the old board’s socket, the parts box, and the blower deck.

    Expect: Inducer / low PS: Inducer on low. Low-fire PS must close. Already closed with inducer off → E1. Never closes → E2. Same physics as GR9T96, ComfortBridge presentation.

  3. 3 Confirm with a number, then the next part

    d4 = card present but wrong family or corrupt. A GMVM97 or GMEC card will not satisfy a GMVC96. Power up only after the card is seated. Configuring without it teaches the next tech nothing. Then set CFM / staging in the menu. There are no heat taps to ‘get close enough.’

    Expect: Data pair: OEM communicating voltage / polarity — never 24 VAC between the data pins. · Motor harness: 14-pin serial ECM, fully seated. No tap plugs. No CT profile harness.

    If fail: Stay on this plate. The out-of-range reading is the part.

    If pass: Reading in range → the next step in this workflow is the repair.

ComfortBridge bus vs 24V fallback

Stat shows a call, furnace idle — or the job was ‘converted’ off a communicating stat.

  1. 1 Prove the call and the live code

    Photograph the triple display and the stat error before touching wires.

    Expect: Write whatever ComfortBridge IFC · three 7-segment digits + menu buttons is showing. Use the IFC menu (not the GR9T96 2-second hold) to read fault history. Write the exact three characters plus any decimal. Power cycle clears live status, not always the stored stack.

    If fail: No call at the IFC → stat / harness. Do not change gas parts.

  2. 2 Isolate the first failed step in the sequence

    Is the IFC in communicating mode or 24V fallback? That changes every next step.

    Expect: Inducer / low PS: Inducer on low. Low-fire PS must close. Already closed with inducer off → E1. Never closes → E2. Same physics as GR9T96, ComfortBridge presentation.

  3. 3 Confirm with a number, then the next part

    Communicating: data pair polarity and splices. This is not 24 VAC. Only one master on the bus. Outdoor crashing the bus will idle the indoor. 24V fallback: W1/W2 at the IFC, then inducer / PS / HSI as a two-stage 96%. CFM still comes from IFC tables. Leftover data wires landed on R/C/W is a fuse (E5) or a dead call, not a bad serial motor.

    Expect: Data pair: OEM communicating voltage / polarity — never 24 VAC between the data pins. · Motor harness: 14-pin serial ECM, fully seated. No tap plugs. No CT profile harness.

    If fail: Stay on this plate. The out-of-range reading is the part.

    If pass: Reading in range → the next step in this workflow is the repair.

Test points

Data pair

OEM communicating voltage / polarity — never 24 VAC between the data pins.

Motor harness

14-pin serial ECM, fully seated. No tap plugs. No CT profile harness.

Shared-data card

Seated on the IFC. Travels with the cabinet on a board swap.

LPS / HPS

Both NO. Closed only when that inducer speed is making the collector setpoint.

Flame rod

µA per this IFC sticker, not the GR9T96 door card.

Gotchas

  • Door cards differ by board generation. A 2014 GMVC96 card is wrong on a later triple-display replacement IFC.
  • GMVM97 looks identical in the basement and is modulating — two-stage staging tests will lie.
  • Amana AMVC96 is the badge twin. Same chart. GM9S96 / GMSS96 is not.
  • Warehouse ‘Goodman 96% IFC’ is often this board. It will not run a GR9T96 9-speed motor.
  • EE on this chart is no 115V / internal — not a ComfortBridge bus code. Diagnose line power first.

Related plates

Install this plate

Install GMVC96 as ComfortBridge two-stage VS. Shared-data card and 14-pin serial motor are mandatory.

Cat IV PVC · ComfortBridge · serial ECM · dual PS · 24V W1/W2 fallback

Cabinet & motor

  • Seat the memory card for this GMVC96 cabinet before power-up. Board-only swaps throw d0/d4.
  • 14-pin serial ECM. A 9-speed GR9T96 motor or an X-13 GMEC96 motor will sit on b0.
  • Amana AMVC96 is the badge twin — same install, different literature cover.

Vent & control

  • PVC Cat IV, primed trap, two PS hoses on two taps — communicating does not remove draft hardware.
  • Data pair is not 24V. ComfortBridge outdoor on the bus, or 24V Y1/Y2 from a conventional outdoor.

First fire

  1. 1Menu: cabinet size, heat CFM, staging. Idle / Ht1 / Ht2 are status words.
  2. 2Heat call: low then high prove. E-codes are draft/gas; b-codes are the blower; d-codes are the card.
  3. 3If a GSZC18 / communicating outdoor is paired, confirm the outdoor actually answers the bus.

Do not on Goodman GMVC96

  • Do not use the GR9T96 2-second fault-recall hold. History is in the ComfortBridge menu.
  • Do not apply GMVM97 percent-fire setup on this two-stage valve.

Maker literature

FieldBench does not host manufacturer files. Each link opens the maker’s own literature page in a new tab.

Warranty and bulletins

Affected models, serial range, symptom, remedy, date. Maker files open on the manufacturer site.

All bulletins
  • Dated GM* certificate

    warranty sheet

    Older Goodman GM* furnace limited warranty

    GM* generation furnace warranty terms · Dated certificate for that generation

  • Dealer portals

    dealer

    Where remaining service letters live

    Current-year service letters not on a public literature page · Maker dealer portal