For 1990-2009 cars

### Circuit Description

The washer switch provides battery power to the washer pump motor. The Intelligent Switching Unit (ISU) monitors the status of the washer switch.

### DTC Descriptor

This diagnostic procedure supports the following DTC:

DTC 022 Front Washer Request Signal Circuit

### Conditions for Running the DTC

• | Battery voltage must be between 9-16 volts.

• | The washer switch is active.

### Conditions for Setting the DTC

The ISU detects an open or short to ground.

### Action Taken When the DTC Sets

The washer pump will be inoperative.

### Conditions for Clearing the DTC

• | The ISU no longer detects an open or short to ground on the washer pump circuit.

• | A history DTC will clear after 40 consecutive ignition cycles if the condition for the malfunction is no longer present.

### Test Description

The numbers below refer to the step numbers on the diagnostic table.

1. This step tests the inactive state of the washer switch.

2. This step tests the active state of the washer switch.

3. After replacement of the ISU, the ISU must be reprogrammed.

Step | Action | Yes | No
--- | --- | --- | ---
Schematic Reference: Wiper/Washer Schematics Connector End View Reference: Component Connector End Views
1 | Did you perform the Diagnostic System Check - Vehicle? | Go to Step 2 | Go to Diagnostic System Check - Vehicle
2 |

1. Install a scan tool.
2. Turn ON the ignition, with the engine OFF.
3. With a scan tool, observe the wiper washer switch parameter in the ISU Wiper/Washer data list.

Does the scan tool display Inactive?

Go to Step 3

Go to Step 5

3 |

1. Activate the washer switch.
2. With a scan tool, observe the wiper washer switch parameter.

Does the wiper washer switch parameter change state?

Go to Step 7

Go to Step 4

4 |

1. Inspect the washer pump motor control circuit for an open or short to ground.
2. Replace Fuse F16 if necessary.

Did you find and correct the condition?

Go to Step 11

Go to Step 7

5 |

1. Turn OFF the ignition.
2. Disconnect the wiper switch.
3. Turn ON the ignition, with the engine OFF.
4. With a scan tool, observe the wiper washer switch parameter.

Does the scan tool display Inactive?

Go to Step 8

Go to Step 6

6 | Test the signal circuit of the washer switch for a short to voltage. Refer to Circuit Testing and Wiring Repairs . Did you find and correct the condition? | Go to Step 11 | Go to Step 7
7 | Inspect for poor connections at the harness connector of the intelligent switching unit (ISU). Refer to Testing for Intermittent Conditions and Poor Connections and Connector Repairs . Did you find and correct the condition? | Go to Step 11 | Go to Step 9
8 | Inspect for poor connections at the harness connector of the wiper switch. Refer to Testing for Intermittent Conditions and Poor Connections and Connector Repairs . Did you find and correct the condition? | Go to Step 11 | Go to Step 10
9 | Important: Perform the program procedure for the ISU. Replace the ISU. Did you complete the replacement? | Go to Step 11 | --
10 | Replace the wiper switch. Refer to Windshield Wiper and Washer Switch Replacement . Did you complete the replacement? | Go to Step 11 | --
11 |

1. Use the scan tool in order to clear the DTCs.
2. Operate the vehicle within the Conditions for Running the DTC as specified in the supporting text.

Does the DTC reset?

Go to Step 2

System OK