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. |
Diagnostic Fault Information
Circuit | Short to Ground | Open/High Resistance | Short to Voltage | Signal Performance |
|---|---|---|---|---|
Rear Window Wiper Motor B+ | 1 | 1 | -- | -- |
Rear Window Wiper Motor Ignition Voltage | 1 | 1 | -- | -- |
Rear Window Wiper/Washer Switch Ignition Voltage | 1 | 1 | -- | -- |
Rear Window Wiper Switch Signal | 1 | 1 | 2 | -- |
Rear Window Wiper Motor Ground | -- | 1 | -- | -- |
1. Rear Window Wiper Motor Inoperative 2. Rear Window Wiper Motor Always On | ||||
Circuit/System Description
The rear wiper is controlled based on an input from the rear wiper/washer switch. When closed, the wiper ON and wiper DELAY switches provide a unique voltage signal to the rear window wiper motor indicating the desired speed. Each switch has a unique resistor that drops the voltage to a specified value which is interpreted by the rear window wiper motor as ON or DELAY. The rear wiper motor receives B+ voltage from the underhood fuse block and accessory voltage from the body control module (BCM).
Reference Information
Schematic Reference
Connector End View Reference
Description and Operation
Rear Wiper/Washer System Description and Operation
Electrical Information Reference
Scan Tool Reference
Control Module References for scan tool information
Circuit/System Verification
Rear wiper switch in the WIPER position. The rear wiper should turn ON.
| ⇒ | If the rear wiper does not turn ON, refer to circuit system testing. |
Circuit/System Testing
- Ignition OFF, disconnect the harness connector at the window wiper/washer switch rear.
- Ignition ON, test for ignition voltage between the ignition voltage circuit terminal 1 and ground
- Ignition OFF, connect the harness connector at the window wiper/washer switch rear. Disconnect the harness connector at the rear window wiper motor.
- Test for less than 10 ohms between the ground circuit terminal 4 and ground.
- Ignition ON, verify a test lamp illuminates between the B+ circuit terminal 5 and ground.
- Ignition ON, rear wiper/washer switch in the WIPER position, test for ignition voltagebetween the signal circuit terminal 1 and ground.
- Liftgate closed, test for infinite resistance betweenthe signal circuit terminal 3 and ground.
- If all circuits test normal, test or replace the rear window wiper/washer module.
| ⇒ | If not the specified value, test the ignition circuit for a short to ground or an open/ high resistance. |
| ⇒ | If greater than the specified range, test the ground circuit for an open/high resistance. |
| ⇒ | If the test lamp does not illuminate, test the B+ circuit for a short to ground or an open/high resistance. |
| ⇒ | If not the specified value, test the signal circuit for a short to ground or an open/high resistance, If the circuit tests normal, replace the window wiper/washer switch rear. |
| ⇒ | If not the specified value, test the signal circuit for a short to ground. |
Repair Instructions
Perform the Diagnostic Repair Verification after completing the diagnostic procedure.
