FieldBench
Carrier codes

Carrier

MA ERR

Protect

MA SENS ERR (JADE LCD example)

JADE two-line LCD: MA / SENS ERR. Mixed-air sensor failed. This one alarms immediately on power-up — others wait the 60-minute setup window.

Walk MA ERR in Diagnose

3 plates — walk the one on the cabinet

First check

1 Damper position vs command

On Carrier 48FC look at the economizer before the compressor. Commanded open? Blade actually open? Linkage off the shaft is a rooftop weekly. Probe mixed air after the damper vs MAT on the module.

Expect: Blade matches the module command. Stuck open = overventilation. Stuck closed = no free cooling.

The rest of the walkthrough is Diagnose.

On the plates

  • Probe mixed air after the damper vs MAT on the module.
  • Ohm the MA sensor. Open/short or a sensor in the OA stream is this code.
  • MAT lying high keeps mechanical cool off. MAT lying low drives the damper shut or trips FREEZING.

Plates that use MA ERR

Same number, other makers

MA ERR on Carrier is not the same code on these plates.