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.

### Diagnostic Fault Information

Circuit | Short to Ground | Open/High Resistance | Short to Voltage | Signal Performance
--- | --- | --- | --- | ---
Headlamp Washer Fluid Pump Control | 1 | 1 | 2 | --
Headlamp Washer Relay Control | B3810 02 | 1 | 1 | --
Headlamp Washer Fluid Pump Ground | -- | 1 | 1 | --
1. Headlamp Washer Inoperative 2. Headlamp Washers Always ON

### Circuit/System Description

The body control module (BCM) controls the washer motor based on an input from the windshield wiper washer 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 front washer switch signal circuit. When this is seen, the BCM will command the front washer fluid pump and the low speed wipers on. When Headlamp Wash Equipped, the headlamps shall be sprayed with wash fluid as a result of an extended Windshield Wash Switch Activation. In order to preserve wash fluid, the feature shall only be allowed to activate if the Low or High Beam Headlamps are active. In addition, after the initial Headlamp Wash operation has been performed, additional headlamp washes shall not be performed for the next 4 Windshield Wash activations or for 48 hours whichever comes first.

### Diagnostic Aids

The headlamp wash feature shall only be allowed to be activate, if the low or high beam headlamps are active too.

### 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 diagnostic tester information

### Circuit/System Verification

Operate the headlamp washer using the S78 Turn Signal/Multifunction Switch. Verify the G16 Headlamp Washer Fluid Pump activates. The low or high beam headlamps are ON.

### Circuit/System Testing

1. Ignition OFF, disconnect the KR2 Headlamp Washer Fluid Pump Relay.
2. Connect a test lamp between the control circuit terminal 86 and ground.
3. Ignition ON, command the headlamp washer ON and OFF using the wiper switch. The test lamp should turn ON and OFF when changing between the commanded states.

⇒ | If the test lamp is always ON, test the control circuit for a short to voltage. If the circuit tests normal, replace the K9 Body Control Module (BCM).

⇒ | If the test lamp is always OFF, test for a short to ground or an open/high resistance on the control circuit. If the circuit tests normal, replace the K9 Body Control Module (BCM).

4. If all circuits test normal, test or replace the KR2 Headlamp Washer Fluid Pump Relay.

### Component Testing

#### Multifunction Switch

#### Static Test

1. Ignition OFF, disconnect the harness connector X3 at the K9 Body Control Module (BCM).
2. Test for less than 5 Ω between ground terminal X3 10 and signal circuit terminal X3 25 while activating the front wash switch.

⇒ | If the resistance is not within the specified range, test for an open/high resistance.

3. Test for greater than 500 kΩ between ground terminal X3 10 and signal circuit terminal X3 25 with not activated front wash switch.

⇒ | If the resistance is not within the specified range, test for a short to ground.

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

#### Dynamic Test

1. Ignition OFF, disconnect the KR2 Headlamp Washer Fluid Pump Relay.
2. Install a 30 A fused jumper wire between the relay terminals 85, 87and 12 V. Install a jumper wire between the relay terminal 86 and ground.
3. Connect a test lamp between relay terminal 30 and ground.
4. Observe the test lamp turns ON and OFF by grounding the relay terminal 86 briefly several times.

⇒ | If the function does not perform as specified, replace the KR2 Headlamp Washer Fluid Pump Relay.

#### Relay Test

1. Ignition OFF, disconnect the KR2 Headlamp Washer Fluid Pump Relay.
2. Test for 60-200 Ω between terminals 85 and 86.

⇒ | If the resistance is not within the specified range, replace the KR2 Headlamp Washer Fluid Pump Relay.

3. Test for infinite resistance between the following terminals:

• | 30 and 86

• | 30 and 87

• | 30 and 85

• | 85 and 87

⇒ | If not the specified value, replace the KR2 Headlamp Washer Fluid Pump Relay.

4. Test for less than 5 Ω between terminals 30 and 87A.

⇒ | If greater than the specified value, replace the KR2 Headlamp Washer Fluid Pump Relay.

5. Install a 10 A fused jumper wire between relay terminal 85 and 12 V. Install a jumper wire between relay terminal 86 and ground. Test for less than 5 Ω between terminals 30 and 87.

⇒ | If greater than the specified range, replace the KR2 Headlamp Washer Fluid Pump Relay.

#### Washer Pump

#### Dynamic Test

1. Ignition OFF, disconnect the harness connector at the G16 Headlamp Washer Fluid Pump.
2. Install a 10 A fused jumper wire between the control terminal 1 and 12 volts. Install a jumper wire between the ground terminal 2 and ground.
3. Verify the G16 Headlamp washer fluid pump is activated.

⇒ | If the G16 Headlamp Washer Fluid Pump does not activate , replace the G16 Headlamp Washer Fluid Pump.

### Repair Instructions

Perform the Diagnostic Repair Verification after completing the diagnostic procedure.

Control Module References for BCM replacement, setup, and programming

Relay Replacement

Headlamp Washer Pump Replacement

Windshield Wiper and Washer Switch Replacement

LInk X for UEC replacement.