P1654 BUICK, CADILLAC, CHEVROLET, GMC: A/C RELAY CONTROL CIRCUIT CONDITIONS
POST UPDATED IN February, 2023
P1654 Code failures by brands
Description of DTC code P1654
The A/C (Air Conditioning) is a system that provides comfort to those who travel in a car. This system has had several changes over the years. There are many components involved in the correct performance of the air conditioning, which is constantly monitored and checked by the corresponding controller (PCM or ECM) to ensure optimal system performance.
The DTC P1654 OBDII on Buick, Cadillac, Chevrolet, and GMC vehicles is related to a fault in the circuit that controls the A/C relay. The code is set when the PCM (Powertrain Control Module) detects an improper voltage level on the ODM ‘B’ output fault line 4 circuit while the engine is running.
Symptoms of fault code P1654
- Check Engine light ON.
- Air conditioning malfunction.
Causes of OBD2 P1654
The P1654 OBD2 diagnostic code is stored for one of the following reasons:
- The air conditioning relay circuit wiring may be damaged.
- The relay circuit may be open or shorted.
- The air conditioning relay may be faulty.
Possible solutions of the DTC code P1654
To troubleshoot the P1654 OBDII fault code, try this:
- To start the diagnosis, we recommend you consult the TSBs.
- Check there is no damage to the wiring in the air conditioning relay circuit. If you discover any burns, wear, or corrosion, carry out repairs.
- Use proper tools to rule out the electrical deficiencies in the air conditioner relay circuit connections. Look for mismatched connections or conditions that cause a short circuit. Fix if necessary.
- Check the integrity of the air conditioning relay, taking into account the diagnostic steps outlined by the manufacturer. If you detect noticeable damage to the relay, make the replacement.
