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 CircuitDiagnostic 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
Connector End View Reference
Description and Operation
Wiper/Washer System Description and Operation
Electrical Information Reference
Scan Tool Reference
Control Module References for scan tool information
Circuit/System Testing
- Ignition OFF, disconnect the harness connector at the rear wiper motor.
- Verify that DTC B1448 remains current.
- Ignition OFF, disconnect the X5 harness connector at the BCM.
- Test for greater than 70 ohms between the BCM accessory voltage circuit terminal 14 and ground.
- If the circuit tests normal, test or replace the BCM.
| ⇒ | If DTC B1448 changed to history, test or replace the rear wiper motor. |
| ⇒ | 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. |
Repair Instructions
Perform the Diagnostic Repair Verification after completing the repair.
| • | Control Module References for BCM replacement, setup, and programming |
