Diagnosis And Testing - Front Wiper And Washer System: Notes

WARNING:

To avoid serious or fatal injury on vehicles equipped with airbags, disable the Supplemental Restraint System (SRS) before attempting any steering wheel, steering column, airbag, Occupant Classification System (OCS), seat belt tensioner, impact sensor or instrument panel component diagnosis or service. Disconnect and isolate the battery negative (ground) cable, then wait two minutes for the system capacitor to discharge before performing further diagnosis or service. This is the only sure way to disable the SRS. Failure to follow these instructions may result in accidental airbag deployment.

If the front wiper motor operates, but the wiper blades do not move on the windshield and the wiper arms are properly installed, replace the ineffective front wiper motor or wiper linkage module. If the washer pump/motor operates, but no washer fluid is dispensed on the glass; or, if the wipers operate, but chatter, lift or do not clear the glass, clean and inspect the front wiper and washer system components as required and. Refer to CLEANING or INSPECTION .

The hardwired front 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 appropriate SYSTEM WIRING DIAGRAMS, details of wire harness routing and retention, connector pin-out information and location views for the various wire harness connectors, splices and grounds. For proper wire repair, and connector repair procedures. Refer to STANDARD PROCEDURE or REMOVAL or INSTALLATION .

However, conventional diagnostic methods will not prove conclusive in the diagnosis of the front wiper and washer system or the electronic controls and communication between other modules and devices that provide some features of the front wiper and washer system. The most reliable, efficient and accurate means to diagnose the front wiper and washer system or the electronic controls and communication related to front wiper and washer system operation requires the use of a diagnostic scan tool. Refer to the appropriate diagnostic information.

NOTE:

The front wiper and washer switches are integral to the right (wiper) multifunction switch in the Steering Column Control Module (SCCM). The multifunction switches communicate with the SCCM microcontroller. The SCCM microcontroller is a gateway to the Controller Area Network (CAN) data bus and communicates with the Body Control Module (BCM) over the CAN bus. The BCM controls front wiper motor operation through wiper relays that are integral to the Printed Circuit Board (PCB) within the BCM.

Before performing any of the following tests, determine whether the other functions of the SCCM multifunction switches are operational. If other SCCM switch functions are ineffective, diagnose and repair that problem before attempting to repair the Wiper and Washer System.

FRONT WIPER AND WASHER SYSTEM DIAGNOSIS
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 low speed and high speed feed circuits between BCM and wiper motor, if required.
	3. Ineffective SCCM inputs or outputs.	3. Use a diagnostic scan tool and the appropriate diagnostic information for additional SCCM diagnosis.
	4. Ineffective BCM inputs or outputs.	4. Use a diagnostic scan tool and the appropriate diagnostic information for additional BCM diagnosis.
	5. Ineffective wiper motor.	5. Test and replace open or shorted wiper motor as required.
WIPERS DO NOT PARK CORRECTLY	1. Ineffective wiper motor park switch input circuit.	1. Test and repair wiper park switch input circuit between BCM and wiper motor if required.
	2. Ineffective BCM inputs or outputs.	2. Use a diagnostic scan tool and the appropriate diagnostic information for additional BCM diagnosis.
	3. Ineffective wiper motor park switch.	3. Test and replace wiper motor, if required.
WIPER MOTOR OPERATES SLOWLY IN ALL SWITCH POSITIONS	1. Ineffective wiper motor.	1. Check amperage draw with linkage disconnected from wiper motor output shaft. Correct draw should be about 2 amperes on Low speed, or 3 amperes on High speed. If incorrect, refer to the appropriate Possible Cause that follows:
	2. Amperage draw too low.	2. Test and repair shorted low and high speed feed circuits, if required.
	3. Amperage draw too high.	3. With linkage disconnected from wiper motor output shaft, check linkage and pivots for binding. If binding is detected, repair or replace wiper linkage module, if required. If no linkage binding detected, replace the wiper motor, if required.
WIPERS RUN AT HIGH SPEED WITH SWITCH LOW SPEED SELECTED OR AT LOW SPEED WITH SWITCH HIGH SPEED SELECTED	1. Ineffective motor feed circuit wiring.	1. Test and repair low speed and high speed feed circuits between BCM and wiper motor, if required.
AUTOMATIC WIPERS ONLY ARE INOPERATIVE	1. Automatic wipers (Rain Sensing) feature has been disabled.	1. Be certain that the automatic wipers (Rain Sensing) feature is enabled in the Customer Programmable Features Settings menu.
AUTOMATIC WIPERS ONLY ARE INOPERATIVE	2. Light Rain Sensor Module (LRSM) gel pack is damaged.	2. Replace the LRSM gel pack, if required.
WASHER PUMP DOES NOT OPERATE	1. Ineffective washer pump ground circuit.	1. Test and repair open washer pump ground circuit if required.
	2. Ineffective washer pump feed circuits.	2. Test and repair washer pump feed circuits between BCM and washer pump, if required.
	3. Ineffective SCCM inputs or outputs.	3. Use a diagnostic scan tool and the appropriate diagnostic information for additional SCCM diagnosis.
	4. Ineffective BCM inputs or outputs.	4. Use a diagnostic scan tool and the appropriate diagnostic information for additional BCM diagnosis.
	5. Ineffective washer pump.	5. Test and replace open or shorted washer pump, if required.