P1536

Refer to Computers and Control Systems Schematics in Computers and Control Systems.

CIRCUIT DESCRIPTION
The engine coolant temperature sensor is a thermister. The PCM determines the temperature of the engine coolant based on the voltage from the sensor. When the sensor is cold, its resistance and voltage are high. When the sensor is warm, its resistance and voltage are low. The PCM sends the coolant temperature to the DIM over the Class 2 data line. The DIM will not request A/C clutch engagement if the engine coolant temperature is high.

CONDITIONS FOR RUNNING THE DTC
The DIM must be powered.

CONDITIONS FOR SETTING THE DTC
The engine coolant temperature is equal to or greater than 121°C (250°F) for more than 2 seconds.

ACTION TAKEN WHEN THE DTC SETS
The A/C clutch turns off.

CONDITIONS FOR CLEARING THE MIL/DTC
^ When the engine coolant temperature drops to less than 119°C (246°F) the DIM will clear the DTC.
^ Use a scan tool in order to clear the MIL/DTC.

DIAGNOSTIC AIDS
If DTC P1536 is stored as a history code it indicates that the 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 the engine from overheating, as when pulling a trailer up a hill. Check the PCM for current or history engine coolant temperature sensor DTCs.