GM Service Manual Online
For 1990-2009 cars only

Diagnostic Instructions

    • 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.

DTC Descriptor

DTC B3922 00: Front Wiper Function Select Circuit

Diagnostic Fault Information

Circuit

Short to Ground

Open/High Resistance

Short to Voltage

Signal Performance

Windshield Wiper Motor Relay Coil Supply Voltage

B3874

2

6

--

Windshield Wiper Switch High Signal

6

4

1

--

Windshield Wiper Switch Low Signal

6

3

B3922 00

--

Windshield Wiper Motor Park Switch Signal

5

5

--

--

Windshield Wiper High Speed Relay Control

7

4

B3875

--

Windshield Wiper Motor High Speed Control

2

4

--

--

Windshield Wiper Motor Low Speed Control

2

3

--

--

Wiper PCB Relay Ground

--

2

--

--

Windshield Wiper Motor Ground

--

2

--

--

Windshield Wiper Switch Ground

--

1

--

--

1. Wipers and Washers Inoperative All Modes

2. Wipers Inoperative All Modes and Washers Work

3. Delay or Low Speed Wipers Inoperative

4. High Speed Wipers Inoperative

5. Wipers Do Not Park

6. Wipers Always On

7. Wipers Operate at High Speed in the Low Speed Mode

Circuit/System Description

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.

Conditions for Running the DTC

The ignition switch is in the ON position.

Conditions for Setting the DTC

The BCM detects a short to ground on the windshield wiper switch low signal circuit.

Action Taken When the DTC Sets

    • The BCM will not activate the low speed output.
    • The windshield wipers will only operate in the high speed mode.

Conditions for Clearing the DTC

    • The DTC will clear the current status when the condition for setting the fault is corrected.
    • A history DTC will clear after 50 consecutive ignition cycles without a fault present.

Reference Information

Schematic Reference

Wiper/Washer Schematics

Connector End View Reference

Component Connector End Views

Description and Operation

Wiper/Washer System Description and Operation

Electrical Information Reference

    •  Circuit Testing
    •  Connector Repairs
    •  Testing for Intermittent Conditions and Poor Connections
    •  Wiring Repairs

Scan Tool Reference

Control Module References for scan tool information

Circuit/System Verification

Ignition ON, observe the scan tool Windshield Wiper Switch parameter while rotating the wiper switch. The reading should change between Off, Intermittent, and Low.

Circuit/System Testing

  1. Ignition OFF, disconnect the harness connector at the turn signal/multifunction switch.
  2. Ignition ON, verify the scan tool Windshield Wiper Switch parameter is not Switch Fault.
  3. If Switch Fault, test the windshield wiper switch low signal circuit terminal H for a short to ground. If the circuit tests normal, replace the BCM.
  4. If all circuits test normal, test or replace the turn signal/multifunction switch.

Component Testing

Multifunction Switch

  1. With the ignition OFF, disconnect the harness connector at the turn signal/multifunction switch.
  2. Test the resistance between terminals  M and  H. Rotate the wiper switch and compare the resistance readings to the values in the Windshield Wiper Switch Values table below for MIST, each DELAY and LOW speed.
  3. If the resistance is not within the specified range, replace the turn signal/multifunction switch.
  4. Test for infinite resistance between terminals M and  K while rotating the wiper switch to MIST, each DELAY and LOW speed positions.
  5. If the less than infinite, replace the turn signal/multifunction switch.
  6. Test for less than 5 ohms of resistance with the wiper switch in the High speed position.
  7. If greater than 5 ohm, replace the turn signal/multifunction switch.
  8. Test for infinite resistance between terminals  M and  G while rotating the wiper switch to MIST, each DELAY and LOW speed positions.
  9. If less than infinite, replace the turn signal/multifunction switch.
  10. Test for less than 5 ohm of resistance while pressing the WASHER switch.
  11. If greater than 5 ohm, replace the turn signal/multifunction switch.

Important: If the switch tests open in any switch position other than Off, test the wiper/washer switch signal circuits for a short to voltage before replacing the switch.

Wiper Switch Values

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

Repair Instructions

Perform the Diagnostic Repair Verification after completing the diagnostic procedure.

    •  Turn Signal Multifunction Switch Replacement
    •  Control Module References for BCM replacement, setup, and programming