For 1990-2009 cars

### Diagnostic Instructions

• | Perform the Diagnostic System Check - Vehicle prior to using this diagnostic procedure.

• | Review Strategy Based Diagnosis for an overview of the diagnostic approach.

• | Diagnostic Procedure Instructions provides an overview of each diagnostic category

### DTC Descriptor

DTC B1325: Device Power Circuit

### Circuit/System Description

With the ignition in either the ACC or ON positions, the HVAC control module should receive a 12V power supply. DTC B1325 will set to indicate the B+ positive supplied to the AHLL control module is below the threshold.

### Conditions for Setting the DTCs

This DTC runs continuously once the following condition is met:

The supplied power to the HVAC control module is between 9 - 16V.

### Action Taken When the DTC Sets

A warning lamp will illuminate.

### Conditions for Clearing the DTC

• | The condition for setting the DTC is no longer present.

• | The DTC can be cleared using a scan tool.

### Reference Information

#### Schematic Reference

HVAC Schematics

#### Connector End View Reference

Component Connector End Views

#### Scan Tool Reference

Control Module References

### Circuit/System Testing

1. Ignition OFF, wait for 30 seconds.
2. Ignition ON, using the scan tool, select the DTC display function. Verify that DTC B1325 is set to current.
3. Ignition OFF, disconnect the HVAC control module harness connector.
4. Ignition ON, test for B+ between the battery positive voltage circuit at the HVAC control module harness connector and a known ground.

⇒ | If not within specified range, test the battery positive voltage circuit for an open/high resistance. If the circuit tests normal replace the HVAC control module.

### Repair Instructions

Perform the Diagnostic Repair Verification , after completing the diagnostic procedure.

HVAC Control Module Replacement