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 B1448: Accessory Power Relay Circuit

### Diagnostic Fault Information

Circuit | Short to Ground | Open/High Resistance | Short to Voltage | Signal Performance
--- | --- | --- | --- | ---
Run/Crank Relay Coil Control | B 1448 00 | 1 | 2 | --
1. Rear wiper and washer inoperative. 2. Rear wiper and washer may operate at inappropriate times.

### Circuit/System Description

The body control module (BCM) supplies accessory voltage as required for the rear wiper motor and controls the RR WASH PCB relay in the underhood fuse block through the accessory voltage circuit from BCM harness connector X5 terminal 14.

### Conditions for Running the DTC

• | The system voltage is between 9-16 volts.

• | The DTC can only run when the output is activated.

### Conditions for Setting the DTC

The DTC will set only when the output is activated and there is a short to ground in the accessory voltage circuit.

### Action Taken When the DTC Sets

The module output driver will be shut down and not supply voltage to the accessory voltage circuit.

### Conditions for Clearing the DTC

• | The current DTC will clear when the module request for the output is removed or the malfunction is no longer present.

• | A history DTC clears when the module ignition cycle counter reaches the reset threshold of 50, without a repeat of the malfunction.

### Reference Information

#### Schematic Reference

Wiper/Washer Schematics

#### Connector End View Reference

Component Connector End Views

#### Description and Operation

Wiper/Washer System Description and Operation

#### Electrical Information Reference

• | Circuit Testing

• | Connector Repairs

• | Testing for Intermittent Conditions and Poor Connections

• | Wiring Repairs

#### Scan Tool Reference

Control Module References for scan tool information

### Circuit/System Testing

1. Ignition OFF, disconnect the harness connector at the rear wiper motor.
2. Verify that DTC B1448 remains current.

⇒ | If DTC B1448 changed to history, test or replace the rear wiper motor.

3. Ignition OFF, disconnect the X5 harness connector at the BCM.
4. Test for greater than 70 ohms between the BCM accessory voltage circuit terminal 14 and ground.

⇒ | If less than the specified range, test the circuit for a short to ground. If the circuit tests normal, test or replace the underhood fuse block.

5. If the circuit tests normal, test or replace the BCM.

### Repair Instructions

Perform the Diagnostic Repair Verification after completing the repair.

• | Underhood Electrical Center or Junction Block Replacement

• | Control Module References for BCM replacement, setup, and programming