DTC P1536: Engine Coolant Temperature Sensor

WARNING: This page is about a different car, the 2002 Oldsmobile Aurora. However, it is still accessible from the selected car via links, so may be relevant.

If DTC P1536 is stored as a history code it indicates that Dash Integration Module (DIM) did receive a high engine coolant temperature message from the PCM. Interrupting A/C compressor operation can occur as a normal function to protect engine from overheating, as when pulling a trailer up a hill. If the condition occurs frequently, check the following for a possible cause:

Inoperative engine cooling fans.
Debris in front of condenser.
Radiator or condenser air shields missing or out of location.
Low coolant level or inoperative thermostat.
Water pump failure.
Check PCM for current or history engine coolant temperature sensor DTCs.
Trailer weight exceeding 1000 lbs. (454 kg) in extreme high ambient temperatures.
Aftermarket products affecting cooling system performance.