FieldBench
Goodman codes

Goodman

b0

Lockout

ECM blower not running

IFC commanded the serial ECM and does not detect it running. Furnace will not operate.

Walk b0 in Diagnose

5 plates — walk the one on the cabinet

First check

1 Reseat the serial plug

On Goodman GMVC80 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 seated at motor and IFC. No tap plugs on this motor.

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

The rest of the walkthrough is Diagnose.

On the plates

  • 14-pin harness fully seated at motor and IFC. No tap plugs on this motor.
  • Line voltage at the motor, wheel free, no water in the winding.
  • Wrong motor (9-speed or CT) in this cabinet will sit here forever.
  • 14-pin seated at motor and IFC.
  • Line voltage, wheel free. A 9-speed or CT motor in this cabinet will sit on b0 forever.
  • 14-pin harness seated at motor and IFC. No tap plugs on this motor.
  • 120 VAC to the motor, wheel free, no wet winding.
  • Do not install an AR9T96 9-speed motor as a ‘cheaper ECM’ — it will not talk this serial bus.

Plates that use b0

Same number, other makers

b0 on Goodman is not the same code on these plates.