For 1990-2009 cars

## Washer Malfunction Sedan

### 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.

### Diagnostic Fault Information

Circuit | Short to Ground | Open/High Resistance | Short to Voltage | Signal Performance
--- | --- | --- | --- | ---
Windshield Washer Switch Signal | 2 | 1 | 1 | --
Windshield Washer Fluid Pump Control | 1 | 1 | 2 | --
Windshield Washer Relay Control | B3873 02 | B3873 04 | B3873 01 | --
Windshield Washer Fluid Pump Ground | -- | 1 | -- | --
Windshield Washer Switch Heated Wash Signal | 4 | 3 | 3 | --
Heated Washer Nozzle Module B+ | 3 | 3 | -- | --
Washer Fluid Heater Enable | B371B 02 | 3 | 3 | --
Heated Washer Nozzle Module Ground | -- | 3 | 3 | --
Heated Washer Nozzle Module Indicator Signal | 6 | 5 | 5 | --
Washer Fluid Level Switch Signal | 8 | 7 | 7 | --
Washer Fluid Level Switch Ground | -- | 7 | -- | --
1. Front Washer Inoperative 2. Front Washer Always ON 3. Heated Washer Inoperative 4. Heated Washer Always ON 5. Heated Washer Nozzle Module Indicator Inoperative

6. Heated Washer Nozzle Module Indicator Always ON

7. Washer Fluid Level Indicator Inoperative

8. Washer Fluid Level Indicator Always ON

### Circuit/System Description

The body control module (BCM) controls the windshield washer fluid pump based on an input from the turn signal / multifunction switch. The BCM monitors the washer switch through the windshield washer switch signal circuit. When the wash switch is closed, ground is supplied to the windshield washer switch signal circuit. When this is the case, the BCM will command the windshield washer fluid pump and the low speed wipers on.

The intent of the heated washer fluid feature is to automatically clear the windshield of snow or ice upon activation. The system may also be used to improve the bug clearing performance of the wash feature under summer driving conditions.

On some vehicles warning information (wash fluid low and heated wash ON / OFF) will be conveyed via the GMLAN to the controls and displays subsystem (responsible for display). This subsystem will provide visual feedback to the customer while in the RUN power mode.

### 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. Ignition ON, observe the scan tool Windshield Washer Switch parameter while activating the S78 Turn Signal / Multifunction Switch. The parameter should change between Active and Inactive.

⇒ | If the value does not change, refer to Multifunction Switch Malfunction.

2. Operate the windshield washer using the S78 Turn Signal / Multifunction Switch. Verify the G24 Windshield Washer Fluid Pump activates. Verify the washer fluid reservoir is filled up.

⇒ | If the G24 Windshield Washer Fluid Pump does not run, refer to Washer Pump Malfunction.

3. Activate the heated washer by using the S78 Turn Signal / Multifunction Switch. Observe the K80 Heated Washer Nozzle Module activates. Verify the washer fluid reservoir is filled up.

⇒ | If the heated washer function does not work, refer to Heated Washer Malfunction.

### Circuit/System Testing

Note: You must perform the Circuit / System Verification before proceeding with Circuit / System Testing.

#### Multifunction Switch Malfunction

1. Ignition OFF, disconnect the X3 harness connector at the K9 Body Control Module (BCM).
2. Ignition OFF, test for less than 5 Ω between the low reference circuit terminal 25 and ground while activating the wash function.

⇒ | If greater than the specified value, test the low reference circuit for an open / high resistance. If the circuit tests normal, replace the S78 Turn Signal / Multifunction Switch.

3. Ignition OFF, test for greater than 500 kΩ between the low reference circuit terminal 25 and ground when the S78 Turn Signal / Multifunction Switch is not used.

⇒ | If less than the specified value, test the signal circuit terminal 25 for a short to ground. If the circuit tests normal, replace the S78 Turn Signal/Multifunction Switch.

4. If all circuits test normal, test or replace the K9 Body Control Module (BCM).

#### Washer Pump Malfunction

1. Ignition OFF, disconnect the harness connector at the G24 Windshield Washer Fluid Pump.
2. Ignition ON, verify a test lamp does not illuminate between the control circuit terminal 1 and the ground circuit terminal 2.

⇒ | If the test lamp illuminates, test the control circuit for a short to voltage.

3. Verify a test lamp illuminates between the control circuit terminal 1 and the ground circuit terminal 2 while activating the wash function.

⇒ | If the test lamp does not illuminate, test the ground circuit for an open / high resistance.

4. Test for less than 5 Ω between the ground circuit terminal 2 and ground.

⇒ | If greater than the specified value, test the ground circuit for an short to voltage or an open / high resistance.

⇒ | If all circuits test normal, replace the X50A Fuse Block - Underhood Primary.

#### Heated Washer Malfunction

1. Ignition ON, command the Washer Fluid Heater test ON and OFF with the scan tool, verify that the heated washer reacts to ON and OFF positions.
2. Ignition OFF, disconnect the harness connectors (X1, X2) at the K80 Heated Washer Nozzle Module.
3. Connect a test lamp between the B+ circuit terminal 1 (X1) and the ground circuits terminal 2 (X1) and terminal 4 (X2). The test lamp should illuminate.

⇒ | If the test lamp does not illuminate, test the ground circuits for an open / high resistance or a short to voltage and the B+ circuit for an open / high resistance or a short to ground.

4. Ignition ON, test for less than 5 Ω between the control circuit terminal 1 (X2) and ground while activating the heated wash function with the S78 Turn Signal / Multifunction Switch.

⇒ | If greater than the specified value, test the control circuit for a short to voltage or an open / high resistance.

5. Ignition ON, connect a test lamp between the signal circuit terminal 5 (X2) and ground. The test lamp should illuminate.

⇒ | If the test lamp does not illuminate, test the signal circuit for an open / high resistance or a short to ground.

6. If all circuits test normal, test or replace the K80 Heated Washer Nozzle Module.

#### Low Washer Fluid Indicator Malfunction

1. Verify the washer fluid reservoir is filled up.
2. Ignition OFF, disconnect the harness connector at the B118B Windshield Washer Fluid Level Switch.
3. Test for less than 5 Ω between the ground terminal B and ground.

⇒ | If greater than the specified value, test the ground circuit for a short to voltage or an open / high resistance.

4. Ignition OFF, disconnect the harness connector at the P16 Instrument Panel Cluster.
5. Test for less than 5 Ω between the signal circuit terminal A at the B118B Windshield Washer Fluid Level Switch harness connector and signal terminal 29 at the P16 Instrument Panel Cluster harness connector.

⇒ | If greater than the specified value, test the signal circuit for a short to voltage or an open / high resistance.

6. Reconnect all harness connectors.
7. Ignition ON, command the Driver Information Center Segment test ON and OFF with the scan tool, verify that the low washer fluid indicator display reacts to ON and OFF positions.

⇒ | If the low washer fluid indicator display stays always ON or always OFF, replace the P16 Instrument Cluster.

8. If the low washer fluid indicator display changes between ON and OFF, test or replace the B118B Windshield Washer Fluid Level Switch.

#### Heated Washer Indicator Malfunction

1. Ignition ON, command the Driver Information Center Segment test ON and OFF with the scan tool, verify that the heated washer indicator display reacts to ON and OFF positions.

⇒ | If the heated washer fluid indicator display stays always ON or always OFF, replace the P16 Instrument Cluster.

2. If the heated washer fluid indicator display changes between ON and OFF, test the signal circuit terminal 2 (X2) at the K80 Heated Washer Nozzle Module for a short to ground or an open / high resistance.

⇒ | If all circuits test normal, test or replace the K80 Heated Washer Nozzle Module.

### Component Testing

#### Multifunction Switch Malfunction

1. Ignition OFF, disconnect the X3 Harness Connector at the K9 Body Control Module (BCM). Test for greater than 500 kΩ between the control circuit terminal 25 and ground.

⇒ | If not the specified value, test the control circuit for a short to ground.

2. Ignition OFF, test for less than 5 Ω between the control circuit terminal 25 and ground while activating the wash function.

⇒ | If greater than the specified value, test the control circuit for a short to voltage or an open / high resistance.

3. Ignition OFF, disconnect the X2 harness connector at the K80 Heated Washer Nozzle Module. Test for less than 5 Ω between the control circuit terminal 5 and ground while activating the heated wash function.

⇒ | If greater than the specified value, test the control circuit for a short to voltage or an open / high resistance.

4. If all circuits test normal, replace the S78 Turn Signal / Multifunction Switch.

#### Washer Pump Malfunction

1. Ignition OFF, disconnect the harness connector at the G24 Windshield Washer Fluid Pump.
2. Install a 10 A fused jumper wire between the control terminal 1 and 12 V. Install a jumper wire between the ground terminal 2 and ground.
3. Verify the G24 Windshield Washer Fluid Pump is activated.

⇒ | If the G24 Windshield Washer Fluid Pump does not activate, replace the G24 Windshield Washer Fluid Pump.

#### Low Washer Fluid Indicator Malfunction

1. Ignition OFF, remove the B118B Windshield Washer Fluid Level Switch.
2. Install a wire at terminal A and terminal B. Observe the resistance while moving the level switch.
3. The resistance should be changing between less than 5 Ω-infinite resistance while moving the level switch.

⇒ | If not the specified range, replace the B118B Windshield Washer Fluid Level Switch.

### Repair Instructions

Perform the Diagnostic Repair Verification after completing the diagnostic procedure.

• | Windshield Wiper and Washer Switch Replacement

• | Windshield Washer Pump Replacement

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

• | LINK X, for UEC replacement.

• | LINK X, for Heated Washer Nozzle Module.

## Washer Malfunction Hatchback or Wagon

### 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.

### Diagnostic Fault Information

Circuit | Short to Ground | Open/High Resistance | Short to Voltage | Signal Performance
--- | --- | --- | --- | ---
Windshield Washer Switch Signal | 2 | 1 | 1 | --
Windshield Washer Fluid Pump Control | 1 | 1 | 2 | --
Windshield Washer Relay Control | B3873 02 | B3873 04 | B3873 01 | --
Windshield Washer Fluid Pump Ground | -- | 1 | -- | --
Windshield Washer Switch Heated Wash Signal | 4 | 3 | 3 | --
Heated Washer Nozzle Module B+ | 3 | 3 | -- | --
Washer Fluid Heater Enable | B371B 02 | 3 | 3 | --
Heated Washer Nozzle Module Ground | -- | 3 | 3 | --
Heated Washer Nozzle Module Indicator Signal | 6 | 5 | 5 | --
Washer Fluid Level Switch Signal | 8 | 7 | 7 | --
Washer Fluid Level Switch Ground | -- | 7 | -- | --
1. Front Washer Inoperative 2. Front Washer Always ON 3. Heated Washer Inoperative 4. Heated Washer Always ON 5. Heated Washer Nozzle Module Indicator Inoperative

6. Heated Washer Nozzle Module Indicator Always ON

7. Washer Fluid Level Indicator Inoperative

8. Washer Fluid Level Indicator Always ON

### Circuit/System Description

The body control module (BCM) controls the windshield washer fluid pump based on an input from the turn signal / multifunction switch. The BCM monitors the washer switch through the windshield washer switch signal circuit. When the wash switch is closed, ground is supplied to the windshield washer switch signal circuit. When this is the case, the BCM will command the windshield washer fluid pump and the low speed wipers on.

The intent of the heated washer fluid feature is to automatically clear the windshield of snow or ice upon activation. The system may also be used to improve the bug clearing performance of the wash feature under summer driving conditions.

On some vehicles warning information (wash fluid low and heated wash ON / OFF) will be conveyed via the GMLAN to the controls and displays subsystem (responsible for display). This subsystem will provide visual feedback to the customer while in the RUN power mode.

### 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. Ignition ON, observe the scan tool Windshield Washer Switch parameter while activating the S78 Turn Signal / Multifunction Switch. The parameter should change between Active and Inactive.

⇒ | If the value does not change, refer to Multifunction Switch Malfunction.

2. Operate the windshield washer using the S78 Turn Signal / Multifunction Switch. Verify the G24 Windshield Washer Fluid Pump activates. Verify the washer fluid reservoir is filled up.

⇒ | If the G24 Windshield Washer Fluid Pump does not run, refer to Washer Pump Malfunction.

3. Activate the heated washer by using the S78 Turn Signal / Multifunction Switch. Observe the K80 Heated Washer Nozzle Module activates. Verify the washer fluid reservoir is filled up.

⇒ | If the heated washer function does not work, refer to Heated Washer Malfunction.

### Circuit/System Testing

Note: You must perform the Circuit / System Verification before proceeding with Circuit / System Testing.

#### Multifunction Switch Malfunction

1. Ignition OFF, disconnect the X3 harness connector at the K9 Body Control Module (BCM).
2. Ignition OFF, test for less than 5 Ω between the low reference circuit terminal 25 and ground while activating the wash function.

⇒ | If greater than the specified value, test the low reference circuit for an open / high resistance. If the circuit tests normal, replace the S78 Turn Signal / Multifunction Switch.

3. Ignition OFF, test for greater than 500 kΩ between the low reference circuit terminal 25 and ground when the S78 Turn Signal / Multifunction Switch is not used.

⇒ | If less than the specified value, test the signal circuit terminal 25 for a short to ground. If the circuit tests normal, replace the S78 Turn Signal / Multifunction Switch.

4. If all circuits test normal, test or replace the K9 Body Control Module (BCM).

#### Washer Pump Malfunction

1. Ignition OFF, disconnect the harness connector at the G24 Windshield Washer Fluid Pump.
2. Ignition ON, verify a test lamp does not illuminate between the control circuit terminal 1 and the ground circuit terminal 2.

⇒ | If the test lamp illuminates, test the control circuit for a short to voltage.

3. Verify a test lamp illuminates between the control circuit terminal 1 and the ground circuit terminal 2 while activating the front wash function.

⇒ | If the test lamp does not illuminate, test the ground circuit for an open / high resistance.

4. Test for less than 5 Ω between the ground circuit terminal 2 and ground.

⇒ | If greater than the specified value, test the ground circuit for a short to voltage or an open / high resistance.

⇒ | If all circuits test normal, replace the X50A Fuse Block - Underhood Primary.

#### Heated Washer Malfunction

1. Ignition ON, command the Washer Fluid Heater test ON and OFF with the scan tool, verify that the heated washer reacts to ON and OFF positions.
2. Ignition OFF, disconnect the harness connectors (X1, X2) at the K80 Heated Washer Nozzle Module.
3. Connect a test lamp between the B+ circuit terminal 1 (X1) and the ground circuits terminal 2 (X1) and terminal 4 (X2). The test lamp should illuminate.

⇒ | If the test lamp does not illuminate, test the ground circuits for an open / high resistance or a short to voltage and the B+ circuit for an open / high resistance or a short to ground.

4. Ignition ON, test for less than 5 Ω between the control circuit terminal 1 (X2) and ground while activating the heated wash function with the S78 Turn Signal/Multifunction Switch.

⇒ | If greater than the specified value, test the control circuit for a short to voltage or an open / high resistance.

5. Ignition ON, connect a test lamp between the signal circuit terminal 5 (X2) and ground. The test lamp should illuminate.

⇒ | If the test lamp does not illuminate, test the signal circuit for an open / high resistance or a short to ground.

6. If all circuits test normal, test or replace the K80 Heated Washer Nozzle Module.

#### Low Washer Fluid Indicator Malfunction

1. Verify the washer fluid reservoir is filled up.
2. Ignition OFF, disconnect the harness connector at the B118B Windshield Washer Fluid Level Switch.
3. Test for less than 5 Ω between the ground terminal B and ground.

⇒ | If greater than the specified value, test the ground circuit for a short to voltage or an open / high resistance.

4. Ignition OFF, disconnect the harness connector at the P16 Instrument Panel Cluster.
5. Test for less than 5 Ω between the signal circuit terminal A at the B118B Windshield Washer Fluid Level Switch harness connector and signal terminal 29 at the P16 Instrument Panel Cluster harness connector.

⇒ | If greater than the specified value, test the signal circuit for a short to voltage or an open / high resistance.

6. Reconnect all harness connectors.
7. Ignition ON, command the Driver Information Center Segment test ON and OFF with the scan tool, verify that the low washer fluid indicator display reacts to ON and OFF positions.

⇒ | If the low washer fluid indicator display stays always ON or always OFF, replace the P16 Instrument Cluster.

8. If the low washer fluid indicator display changes between ON and OFF, test or replace the B118B Windshield Washer Fluid Level Switch.

#### Heated Washer Indicator Malfunction

1. Ignition ON, command the Driver Information Center Segment test ON and OFF with the scan tool, verify that the heated washer indicator display reacts to ON and OFF positions.

⇒ | If the heated washer fluid indicator display stays always ON or always OFF, replace the P16 Instrument Cluster.

2. If the heated washer fluid indicator display changes between ON and OFF, test the signal circuit terminal 2 (X2) at the K80 Heated Washer Nozzle Module for a short to ground or an open / high resistance.

⇒ | If all circuits test normal, test or replace the K80 Heated Washer Nozzle Module.

### Component Testing

#### Multifunction Switch Malfunction

1. Ignition OFF, disconnect the X3 Harness Connector at the K9 Body Control Module (BCM). Test for greater than 500 kΩ between the control circuit terminal 25 and ground.

⇒ | If not the specified value, test the control circuit for a short to ground.

2. Ignition OFF, test for less than 5 Ω between the control circuit terminal 25 and ground while activating the wash function.

⇒ | If greater than the specified value, test the control circuit for a short to voltage or an open / high resistance.

3. Ignition OFF, disconnect the X2 harness connector at the K80 Heated Washer Nozzle Module. Test for less than 5 Ω between the control circuit terminal 5 and ground while activating the heated wash function.

⇒ | If greater than the specified value, test the control circuit for a short to voltage or an open / high resistance.

4. If all circuits test normal, replace the S78 Turn Signal / Multifunction Switch.

#### Washer Pump Malfunction

1. Ignition OFF, disconnect the harness connector at the G24 Windshield Washer Fluid Pump.
2. Install a 10 A fused jumper wire between the control terminal 1 and 12 V. Install a jumper wire between the ground terminal 2 and ground.
3. Verify the G24 Windshield Washer Fluid Pump is activated.

⇒ | If the G24 Windshield Washer Fluid Pump does not activate, replace the G24 Windshield Washer Fluid Pump.

#### Low Washer Fluid Indicator Malfunction

1. Ignition OFF, remove the B118B Windshield Washer Fluid Level Switch.
2. Install a wire at terminal A and terminal B. Observe the resistance while moving the level switch.
3. The resistance should be changing between less than 5 Ω-infinite resistance while moving the level switch.

⇒ | If not the specified range, replace the B118B Windshield Washer Fluid Level Switch.

### Repair Instructions

Perform the Diagnostic Repair Verification after completing the diagnostic procedure.

• | Windshield Wiper and Washer Switch Replacement

• | Windshield Washer Pump Replacement

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

• | LINK X, for UEC replacement.

• | LINK X, for Heated Washer Nozzle Module.