• | 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 |
---|---|---|---|---|
Windshield Wiper Switch High Signal | 2 | 2 | 2 | -- |
Windshield Wiper Switch Low Signal | 3 | B3922 00 | 3 | -- |
Windshield Wiper Motor Park Switch Signal | 4 | 4 | -- | -- |
Windshield Wiper High Speed Relay Control | 2 | 2 | B3875 00 | -- |
Windshield Wiper Low Speed Relay Control | B3715 02 | 3 | 3 | -- |
Windshield Wiper Motor High Speed Control | 2 | 2 | 2 | -- |
Windshield Wiper Motor Low Speed Control | 3 | 3 | 3 | -- |
Windshield Wiper Washer Switch Ground | -- | 1 | 1 | -- |
Windshield Wiper Motor Ground | -- | 1 | 1 | -- |
Underhood Fuse Block Ground | -- | 1 | 1 | -- |
1. Wipers inoperative in all speeds 2. High speed wiper malfunction 3. Delay and/or low speed wiper malfunction 4. Wipers do not park |
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 different PCB relays which control the desired wiper speed, high or low.
A low speed wiper request is present
A short to ground is detected in the windshield wiper low speed relay control circuit
Low speed wiper operation is suspended
• | A current DTC will clear when the condition for setting the fault is no longer seen |
• | A history DTC will clear after 50 consecutive ignition cycles without a fault present |
Wiper/Washer Connector End Views
Wiper/Washer System Description and Operation
Ignition ON, wiper switch in the LO position. Verify the windshield wipers are cycling at the low speed.
⇒ | If the test lamp is always ON, test the control circuit for a short to voltage. If the circuit tests normal, replace the BCM. |
⇒ | 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 BCM. |
Perform the Diagnostic Repair Verification after completing the diagnostic procedure
• | Control Module References for BCM replacement, setup, and programming |