For 1990-2009 cars

### 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 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

### Circuit/System Description

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.

### Conditions for Running the DTC

The ignition is ON.

### 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 only operate the windshield wipers in the high speed mode.

### Conditions for Clearing the DTC

• | 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.

### 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

1. Wiper switch in the LO position, verify the scan tool Windshield Wiper Switch parameter is Low.
2. Wiper switch in the HIGH position, verify the scan tool Wiper High Speed Switch parameter is Active
3. Wiper switch in the INT position, verify the scan tool Windshield Wiper Switch parameter is Intermittent.
4. Wiper switch in the INT position, observe the scan tool Wiper Delay Setting parameter while cycling the delay adjustment switch from long delay to short delay. The parameter should cycle between D1 and D5 as each delay position is selected.

### Circuit/System Testing

1. Ignition OFF, disconnect the harness connector at the windshield wiper switch.
2. Ignition OFF, test for less than 20 ohms of resistance between the ground circuit terminal D and ground.

⇒ | If greater than the specified range, test the ground circuit for an open/high resistance. If the circuit test normal, replace the BCM.

3. Ignition ON, verify the scan tool Windshield Wiper Switch parameter is Off.

⇒ | If not the specified value, test the signal circuit terminal E for a short to ground. If the circuit tests normal, replace the BCM.

4. Install a 3A fused jumper wire between the signal circuit terminal E and ground. Verify the scan tool Windshield Wiper Switch parameter is Switch Fault.

⇒ | 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.

5. If all circuits test normal, test or replace the windshield wiper washer switch.

### Component Testing

#### Windshield Wiper Washer Switch

1. With the wiper switch in the HIGH position, test for less than 2 ohms of resistance between the ground terminal D and the signal terminal C.

⇒ | If greater than the specified range, replace the windshield wiper washer switch.

2. While cycling the wiper switch through each delay and speed position, test for the specified resistance between the ground terminal D and the signal terminal E.

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.

#### 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
High | 300-364 Ω

⇒ | If any switch position is not within the specified range, replace the windshield wiper washer switch.

### Repair Instructions

Perform the Diagnostic Repair Verification after completing the diagnostic procedure

• | Windshield Wiper and Washer Switch Replacement

• | Control Module References for BCM replacement, setup, and programming