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 WPR1 relay control circuit which energizes the WPR1 relay, allowing the battery positive voltage from FTR WPR fuse through the switched side of the WPR1 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 on the windshield wiper switch low 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 scan tool display the correct positions? | Go to Testing for Intermittent Conditions and Poor Connections | Go to Step 3 |
3 |
Does the test lamp illuminate? | Go to Step 7 | Go to Step 4 |
4 |
Does the test lamp illuminate? | Go to Step 8 | Go to Step 5 |
5 |
Does the test lamp illuminate at each switch position? | Go to Step 9 | Go to Step 6 |
6 | 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 11 | Go to Step 10 |
7 | 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 11 | -- |
8 | 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 11 | -- |
9 | Replace the BCM. Refer to Control Module References for replacement, setup, and programming. Did you complete the replacement? | Go to Step 11 | -- |
10 | Replace the windshield wiper/washer switch. Refer to Turn Signal Multifunction Switch Replacement . Did you complete the replacement? | Go to Step 11 | -- |
11 |
Does the DTC reset? | Go to Step 2 | System OK |