P1531

DTC P1531

CIRCUIT DESCRIPTION
The dash integration module (DIM) monitors the refrigerant temperature through the A/C refrigerant low temperature sensor. When the refrigerant is cold, the sensor resistance and signal voltage are high. When the refrigerant is warm, the sensor resistance and signal voltage are low. The DIM will not request A/C compressor clutch engagement when the refrigerant temperature is low enough to cause the A/C evaporator core to freeze.

DTC DESCRIPTOR
This diagnostic procedure supports the following DTC:
DTC P1531 Air Conditioning A/C Evaporator Temperature Sensor Circuit

CONDITIONS FOR RUNNING THE DTC
The ignition is turned ON.

CONDITIONS FOR SETTING THE DTC
The DIM detects the signal circuit is less than 127°C (261°F) or greater than -36°C (-34°F).

ACTION TAKEN WHEN THE DTC SETS
- A default value will be used by the DIM.
- The A/C compressor clutch will not engage.

CONDITIONS FOR CLEARING THE DTC
- The DTC will become history if the DIM no longer detects a failure.
- The history DTC will clear after 40 fault-free ignition cycles.
- The DTC can be cleared with a scan tool.

DIAGNOSTIC AIDS
Test the following conditions:
- Visually inspect the sensor for contamination or damage.
- Inspect for the following that may affect the sensors accuracy.
- A malfunction within the refrigerant system causing low pressure.
- Visually inspect the A/C components and lines for damage.
- If condition not present refer to Testing for Intermittent Conditions and Poor Connections in Diagnostic Aids.

TEST DESCRIPTION

Steps 1-10:

Steps 11-12:

The numbers below refer to the step numbers on the diagnostic table.
3. This step tests for the proper operation of the circuit in the high voltage range.
4. This step tests for the proper operation of the circuit in the low voltage range. If the fuse in the jumper opens when you perform this test, the signal circuit is shorted to voltage.
11. Perform the recalibration procedure for the dash integration module.