The body control module (BCM) monitors the windshield wiper switch low signal circuit. When the wiper switch is placed in a low position, a signal is applied to the BCM through the windshield wiper switch low signal circuit. The BCM then applies a battery positive voltage to the WIPER relay control circuit which energizes the WIPER relay, allowing the battery positive voltage from WIPER/WS fuse through the switched side of the WIPER relay to the windshield wiper motor.
This diagnostic procedure supports the following DTC:
DTC B3922 Front Wiper Select Circuit
• | The ignition switch is in the ON position. |
• | The ignition voltage is between 9-16 volts. |
• | The BCM detects an short to battery positive voltage or a short to ground on the windshield wiper switch low signal circuit. |
• | The BCM detects a short to ground in the windshield wiper motor park switch signal circuit. |
The windshield wipers will only function in the high mode.
• | The DTC will clear on current status after the condition for setting the fault is corrected. |
• | A history DTC will clear after 100 consecutive ignition cycles without a fault present. |
• | History and current DTCs can be cleared using a scan tool. |
Perform a visual inspection for loose or poor connections at all related components. Refer to Testing for Intermittent Conditions and Poor Connections .
Step | Action | Yes | No |
---|---|---|---|
Schematic Reference: Wiper/Washer Schematics Connector End View Reference: Master Electrical Component List | |||
1 | Did you perform the Diagnostic System Check - Vehicle? | Go to Step 2 | |
2 |
Does the wipers operate correctly? | Go to Testing for Intermittent Conditions and Poor Connections | Go to Step 3 |
3 |
Does the test lamp illuminate? | Go to Step 9 | Go to Step 4 |
4 |
Does the test lamp illuminate? | Go to Step 10 | Go to Step 5 |
5 |
Does the DMM show continuity at each switch position? | Go to Step 6 | Go to Step 8 |
6 |
Does the test lamp illuminate? | Go to Step 7 | Go to Step 12 |
7 | Test for a short to ground in the windshield wiper motor park switch signal circuit. Refer to Circuit Testing and Wiring Repairs . Did you find and correct the condition? | Go to Step 14 | Go to Step 11 |
8 | Test for a poor connection or an open in the wiper switch low signal circuit. Refer to Circuit Testing and Wiring Repairs . Did you find and correct the condition? | Go to Step 14 | Go to Step 13 |
9 | Repair a short to battery positive voltage in the wiper switch low signal circuit. Refer to Circuit Testing and Wiring Repairs . Did you complete the repair? | Go to Step 14 | -- |
10 | Repair a short to ground in the wiper switch low signal circuit. Refer to Circuit Testing and Wiring Repairs . Did you complete the repair? | Go to Step 14 | -- |
11 | Replace the windshield wiper motor. Refer to Windshield Wiper Motor Replacement . Did you complete the repair? | Go to Step 14 | -- |
12 | Replace the BCM. Refer to Control Module References for replacement, setup, and programming. Did you complete the replacement? | Go to Step 14 | -- |
13 | Replace the windshield wiper/washer switch. Refer to Windshield Wiper and Washer Switch Replacement . Did you complete the replacement? | Go to Step 14 | -- |
14 |
Does the DTC reset? | Go to Step 2 | System OK |