Pinpoint Test B: The Wipers Are Inoperative - Rear Window
Wipers and Washers
Pinpoint Test B: The Wipers are Inoperative - Rear Window
Refer to Wiring Diagram Set 81, Wipers and Washers for schematic and connector information Electrical Diagrams.
Normal Operation
Power is supplied from the Central Junction Box (CJB) to the Body Control Module (BCM) for the rear window wiper system when the ignition is in the ON position. The BCM (Body Control Module) supplies a signal voltage(s) to the wiper/washer switch for the CONTINUOUS and INTERMITTENT wiper functions. Both functions share a dedicated signal (sense) line. The wiper/washer switch physically grounds the signal voltage(s) when a function is selected. The BCM (Body Control Module) then reacts to the grounded signal voltage(s) and its integral electronics make a decision on which wiper system function to carry out (depending on the windshield wiper setting). Ground is supplied to the rear window wiper motor through its own dedicated circuit.
This pinpoint test is intended to diagnose the following:
- Fuse(s)
- Wiring, terminals or connectors
- Wiper/washer switch
- Rear window wiper motor
- BCM (Body Control Module)
PINPOINT TEST B : THE WIPERS ARE INOPERATIVE - REAR WINDOW
B1 CHECK FOR BCM (Body Control Module) DTCs
- Ignition ON.
- Enter the following diagnostic mode on the scan tool: Self-Test- BCM (Body Control Module).
Are any BCM (Body Control Module) DTCs present?
Yes
REFER to the Body Control Module (BCM) DTC Chart for further diagnosis Wiper and Washer Systems.
No
GO to B2.
B2 CHECK THE BCM (Body Control Module) PID REAR WIPER INPUT SWITCH STATUS (R_WP-SW)
- Enter the following diagnostic mode on the scan tool: DataLogger- BCM (Body Control Module).
- Monitor the BCM (Body Control Module) PID R_WP-SW while operating the wiper/washer switch in the rear wiper mode.
Does the status of the PID match the wiper/washer switch setting?
Yes
GO to B5.
No
GO to B3.
B3 CHECK THE WIPER/WASHER SWITCH
- Ignition OFF.
- Disconnect: Wiper/Washer Switch C2081.
- Carry out the wiper/washer switch component test.
Does the wiper/washer switch pass the component test?
Yes
GO to B4.
No
INSTALL a new wiper/washer switch. TEST the system for normal operation.
B4 CHECK THE WIPER GROUND CIRCUIT FROM THE BCM (Body Control Module) AND THE REAR WIPER INTERVAL CIRCUIT
- Disconnect: BCM (Body Control Module) C2280E.
- Disconnect: BCM (Body Control Module) C2280F.
- Measure the resistance between wiper/washer switch C2081-4, circuit CRW20 (GY/YE), harness side and BCM (Body Control Module) C2280E-5, circuit CRW20 (GY/YE), harness side and between wiper/washer switch C2081-5, circuit CRW17 (GN/VT), harness side and BCM (Body Control Module) C2280F-16, circuit CRW17 (GN/VT), harness side.
Are the resistances less than 5 ohms?
Yes
GO to B5.
No
REPAIR the affected circuit. TEST the system for normal operation.
B5 CHECK THE REAR WINDOW WIPER MOTOR GROUND FOR AN OPEN OR HIGH RESISTANCE
- Ignition OFF.
- Disconnect: Rear Window Wiper Motor C4218.
- Measure the resistance between rear window wiper motor C4218-3, circuit GD143 (BK/VT), harness side and ground.
Is the resistance less than 5 ohms?
Yes
GO to B6.
No
REPAIR the circuit. TEST the system for normal operation.
B6 CHECK THE BCM (Body Control Module) VOLTAGE
- Disconnect: BCM (Body Control Module) C2280B.
- Ignition ON.
- Measure the voltage between BCM (Body Control Module) C2280B-15, circuit CBP13 (GY/BN), harness side and ground.
Is the voltage greater than 10 volts?
Yes
GO to B7.
No
VERIFY Central Junction Box (CJB) fuse 13 (15A) is OK. If OK, REPAIR circuit CBP13 (GY/BN) for an open or high resistance. If not OK, REFER to the Wiring Diagrams to identify the possible causes of the short to ground Electrical Diagrams.
B7 CHECK REAR WINDOW WIPER MOTOR SUPPLY AND RELAY OUTPUT CIRCUITS FOR AN OPEN OR HIGH RESISTANCE
- Ignition OFF.
- Disconnect: BCM (Body Control Module) C2280C.
- Measure the resistance between rear window wiper motor C4218-1, circuit CRW02 (GY/BU), harness side and BCM (Body Control Module) C2280C-11, circuit CRW02 (GY/BU), harness side and between rear window wiper motor C4218-2, circuit CRW05 (BU), harness side and BCM (Body Control Module) C2280C-9, circuit CRW05 (BU), harness side.
Are the resistances less than 5 ohms?
Yes
GO to B8.
No
REPAIR the affected circuit. TEST the system for normal operation.
B8 CHECK FOR VOLTAGE TO THE REAR WINDOW WIPER MOTOR USING THE BCM (Body Control Module) PID REAR WIPER RELAY (WPR_RLY_REAR)
- Connect: BCM (Body Control Module) C2280B.
- Connect: BCM (Body Control Module) C2280C.
- Connect: BCM (Body Control Module) C2280E.
- Connect: BCM (Body Control Module) C2280F.
- Connect: Wiper/Washer Switch C2081.
- Ignition ON.
- Command the BCM (Body Control Module) PID WPR_RLY_REAR on.
- Measure the voltage between rear window wiper motor C4218-1, circuit CRW02 (GY/BU), harness side and ground and between rear window wiper motor C4218-2, circuit CRW05 (BU), harness side and ground.
Are the voltages greater than 10 volts?
Yes
GO to B9.
No
GO to B10.
B9 CHECK FOR CORRECT WIPER MOTOR OPERATION
- Ignition OFF.
- Inspect rear window wiper motor C4218 for the following conditions:
- corrosion
- damaged or pushed out pins
- Connect the rear window wiper motor C4218 and make sure it seats correctly.
- Operate the system and verify if the concern is still present.
Is the concern still present?
Yes
INSTALL a new rear window wiper motor. REFER to Wiper Motor - Rear Window Wiper Motor - Rear Window. TEST the system for normal operation.
No
The system is operating correctly at this time. Concern may have been caused by a loose or corroded connector.
B10 CHECK FOR CORRECT BCM (Body Control Module) OPERATION
- Ignition OFF.
- Inspect the BCM (Body Control Module) connectors for the following conditions:
- corrosion
- damaged or pushed out pins
- Connect the BCM (Body Control Module) connectors and make sure they seat correctly.
- Connect: Rear Window Wiper Motor C4218.
- Operate the system and verify if the concern is still present.
Is the concern still present?
Yes
INSTALL a new BCM (Body Control Module). TEST the system for normal operation.
No
The system is operating correctly at this time. Concern may have been caused by a loose or corroded connector.