What does code P1543 mean?

Q: What does code P1543 mean?

A/C System Performance. P1543 on a GM vehicle means the powertrain control module (PCM) has detected that the air conditioning (A/C) system is not performing as expected, typically because the refrigerant pressure sensor or A/C compressor clutch circuit is not responding within the programmed parameters. The PCM monitors the A/C pressure sensor signal and compressor clutch operation to verify that the system can achieve the requested cooling performance, and it sets this code when the measured pressure or clutch feedback does not match the commanded state.

DTC codes / GM codes / P1543

P1543 · GMA/C System Performance

P1543 on a GM vehicle means the powertrain control module (PCM) has detected that the air conditioning (A/C) system is not performing as expected, typically because the refrigerant pressure sensor or A/C compressor clutch circuit is not responding within the programmed parameters. The PCM monitors the A/C pressure sensor signal and compressor clutch operation to verify that the system can achieve the requested cooling performance, and it sets this code when the measured pressure or clutch feedback does not match the commanded state.

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.