What does code P1542 mean?

Q: What does code P1542 mean?

A/C System High Pressure High Temperature. P1542 on GM vehicles indicates the air conditioning (A/C) system has exceeded a safe pressure or temperature threshold, as reported by the A/C refrigerant pressure sensor or a dedicated temperature sensor. The powertrain control module (PCM) or body control module (BCM) sets this code when the signal from the high-pressure sensor indicates pressure above a calibrated limit, or when the high-side temperature exceeds a set value, often to protect the compressor from damage.

DTC codes / GM codes / P1542

P1542 · GMA/C System High Pressure High Temperature

P1542 on GM vehicles indicates the air conditioning (A/C) system has exceeded a safe pressure or temperature threshold, as reported by the A/C refrigerant pressure sensor or a dedicated temperature sensor. The powertrain control module (PCM) or body control module (BCM) sets this code when the signal from the high-pressure sensor indicates pressure above a calibrated limit, or when the high-side temperature exceeds a set value, often to protect the compressor from damage.

SystemPowertrain

Code typeGM specific

SeverityMedium

Fix difficultyIntermediate

AreaVehicle speed, idle control and auxiliary inputs

Guidance is general and written for GM vehicles. Exact tests and values vary by model, so confirm the fault before replacing parts.