• | 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. |
Circuit | Short to Ground | Open/High Resistance | Short to Voltage | Signal Performance |
---|---|---|---|---|
WIPER 2 Relay B+ | 1, 2 | 1, 2 | -- | -- |
Windshield Wiper Switch Signal | B3922 00 | 1 | 1 | -- |
Windshield Wiper Switch High Signal | 4 | 2 | 2 | -- |
Windshield Wiper Motor Park Switch Signal | 3 | 3 | -- | -- |
WIPER 1 Relay Control | B3715 02 | 1 | 4 | -- |
WIPER 2 Relay Control | 4 | 2 | B3875 00 | -- |
Windshield Wiper Motor High Speed Control | 2 | 2 | 4 | -- |
Windshield Wiper Motor Low Speed Control | 1 | 1 | 4 | -- |
Windshield Wiper Switch Low Reference | -- | 1, 2 | 1, 2 | -- |
Windshield Wiper Motor Ground | -- | 1, 2, 3 | -- | -- |
WIPER 1 Relay Ground | -- | 1 | -- | -- |
1. Delay or Low Speed Wipers Inoperative 2. High Speed Wipers Inoperative 3. Wipers Do Not Park 4. Wipers Always ON |
The body control module (BCM) controls the wiper motor based on input from the windshield wiper washer switch. The BCM monitors the wiper washer switch through three separate signal circuits and a ground circuit. The windshield wiper switch high signal circuit is used to determine high speed wiper operation, the windshield wiper switch low signal is used to determine low speed, intermittent, and mist operation through the use of a resistor ladder, and windshield washer switch signal circuit is used to determine washer operation.
The BCM controls the windshield wiper motor through two output controls, controlling two relays which determine the desired wiper speed, high or low.
Wiper/Washer System Description and Operation
Control Module References for scan tool information
⇒ | If the Windshield Wiper Switch parameter is incorrect in the Low or High switch positions, refer to the Multifunction Switch Circuit Test and/or the Turn Signal Multifunction Switch Component Test. |
⇒ | If the Wiper Park Switch parameter is always Active or Inactive, refer to Wipers do not Park Circuit Test. |
⇒ | If the test lamp does not turn on and off while changing between the commanded states, refer to WIPER 1 Relay Control Circuit Test. |
⇒ | If the windshield wipers are inoperative in 1 or more of the delay settings only, test or replace the turn signal multifunction switch. |
⇒ | If the windshield wipers operate at high speed while the switch is in the Low position, refer to WIPER 2 Relay Control Circuit Test. |
⇒ | If the windshield wipers operate at low speed while the switch is in the High position, refer to WIPER 2 Relay Control Circuit Test. |
⇒ | If the windshield wipers are inoperative in the Low or High switch positions, refer to Wiper Motor Circuit Test and/or the Wiper Motor Component Test. |
⇒ | If greater than the specified range, test the low reference circuit for an open/high resistance. If the circuit tests normal, replace the BCM. |
⇒ | If not the specified value, test the signal circuit terminal N for a short to ground. If the circuit tests normal, replace the BCM. |
⇒ | If not the specified value, test the signal circuit terminal K for a short to ground. If the circuit tests normal, replace the BCM. |
⇒ | If not the specified value, test the signal circuit for a short to voltage or an open/high resistance. If the circuit tests normal, replace the BCM. |
⇒ | If not the specified value, test the signal circuit for a short to voltage or an open/high resistance. If the circuit tests normal, replace the BCM. |
⇒ | If not the specified value, test the signal circuit terminal 3 for a short to ground. If the circuit tests normal, replace the BCM. |
⇒ | If not the specified value, test the signal circuit for an open/high resistance. If the circuit tests normal, replace the BCM. |
⇒ | If the low speed wipers are on, test the relay control circuit terminal 20 for a short to voltage. If the circuit tests normal, replace the underhood fuse block. |
⇒ | If the low speed wipers are not on, test the relay control circuit for an open/high resistance or short to ground. If the circuit tests normal replace the underhood fuse block. |
⇒ | If the high speed wipers are on, test the WIPER 2 relay control circuit terminal 21 for a short to ground. If the circuit tests normal, replace the underhood fuse block. |
⇒ | If the high speed wipers are not on, test the relay control circuit for an open/high resistance or short to voltage. If the circuit tests normal replace the underhood fuse block. |
⇒ | If greater than the specified range, test the ground circuit for an open/high resistance. |
⇒ | If the test lamp is always ON, test the control circuit for a short to voltage. If the circuit tests normal, replace the underhood fuse block. |
⇒ | If the test lamp is always OFF, test the control circuit for a short to ground or an open/high resistance. If the circuit tests normal, replace the underhood fuse block. |
⇒ | If the test lamp is always ON, test the control circuit for a short to voltage. If the circuit tests normal, replace the underhood fuse block. |
⇒ | If the test lamp is always OFF, test the control circuit for a short to ground or an open/high resistance. If the circuit tests normal, replace the underhood fuse block. |
⇒ | If greater than the specified range, replace the windshield wiper washer switch. |
Important: If the switch tests open in any switch position other than Off, test the signal circuits for a short to voltage before replacing the switch.
Switch Position | Resistance |
---|---|
Off | Infinite |
Mist | 300-364 Ω |
Delay 1 | 3.48K-4.25K Ω |
Delay 2 | 2.52K-3.08K Ω |
Delay 3 | 1.78K-2.18K Ω |
Delay 4 | 1.17K-1.44K Ω |
Delay 5 | 697-851 Ω |
Low | 300-364 Ω |
⇒ | If the wiper motor is not in the low speed mode replace the motor. |
⇒ | If the wiper motor is not in the high speed mode replace the motor. |
Perform the Diagnostic Repair Verification after completing the diagnostic procedure.
• | Control Module References for BCM replacement, setup, and programming |