Diagnosis and Testing: Rear
If the rear wiper motor operates, but the wiper motor output shaft does not move, replace the ineffective rear wiper motor. If the washer pump/motor operates, but no washer fluid is dispensed on the glass; or, if the wiper operates, but chatters, lifts, or does not clear the glass, clean and inspect the rear wiper and washer system components as required. See Cleaning and Inspection .
The hard wired rear wiper and washer system circuits and components may be diagnosed using conventional diagnostic tools and procedures. Refer to the appropriate wiring information. The wiring information includes wiring diagrams, proper wire and connector repair procedures, details of wire harness routing and retention, connector pin-out information and location views for the various wire harness connectors, splices and grounds.
However, conventional diagnostic methods will not prove conclusive in the diagnosis of the rear wiper and washer system or the electronic controls or communication between other modules and devices that provide some features of the rear wiper and washer system. The most reliable, efficient, and accurate means to diagnose the rear wiper and washer system or the electronic controls and communication related to rear wiper and washer system operation requires the use of a diagnostic scan tool. Refer to the appropriate diagnostic information.
| CONDITION | POSSIBLE CAUSES | CORRECTION |
|---|---|---|
| WIPER MOTOR DOES NOT OPERATE IN ANY SWITCH POSITION | 1. Ineffective motor ground circuit. | 1. Test and repair open wiper motor ground circuit if required. |
| 2. Ineffective motor feed circuits. | 2. Test and repair motor feed circuit between TIPM and rear wiper motor if required. | |
| 3. Ineffective EMIC (CCN) inputs or outputs. | 3. Use a diagnostic scan tool to test the EMIC (CCN) inputs and outputs. Refer to the appropriate diagnostic information. | |
| 4. Ineffective TIPM inputs or outputs. | 4. Use a diagnostic scan tool to test the TIPM inputs and outputs. Refer to the appropriate diagnostic information. | |
| 5. Ineffective wiper motor. | 5. Test and replace open or shorted wiper motor if required. | |
| WIPER MOTOR OPERATES SLOWLY | 1. Improper wiper motor amperage draw. | 1. Check amperage draw with wiper arm disconnected from rear wiper motor output shaft. Correct draw should be about 6 amperes. If incorrect, refer to the appropriate Possible Cause that follows: |
| 2. Amperage draw too low. | 2. Test and repair the shorted rear wiper motor signal and fused ignition switch output (run - accessory) circuits if required. | |
| 3. Amperage draw too high. | 3. With wiper arm disconnected from wiper motor output shaft check for binding between output shaft and rubber grommet in liftgate glass. If binding is detected, lubricate or replace grommet if required. If no binding is detected, replace the wiper motor if required. |