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 |
|---|---|---|---|---|
Wiper Motor Supply | 1 | 1 | -- | -- |
Wiper Switch 12-Volt Reference | 2 | 2 | -- | |
Wiper Switch Signal 1 | 2 | 2 | -- | |
Wiper Switch High Signal | 3 | 4 | -- | -- |
Wiper Switch Ground | -- | 4 | -- | -- |
Wiper Motor Ground | -- | 1 | -- | -- |
1. Wiper motor inoperative in all modes 2. Wiper motor inoperative in all low speed modes 3. Wiper motor always on at high speed 4. Wiper motor inoperative in high speed | ||||
Circuit/System Description
Accessory voltage and ground is supplied to the windshield wiper motor and provides the power for operating the wiper motor and logic power to the wiper motor module. The WASH, MIST, LOW, and DELAY modes are controlled by the windshield wiper/washer switch through a series of internal resistors. The windshield wiper switch supply voltage circuit is a 12-volt reference from the wiper motor module to the wiper/washer switch, and the switch position determines the point on the resistor assembly where the reference voltage is applied. The windshield wiper switch signal 1 circuit supplies the voltage from the resistor assembly to the wiper motor module and the signal voltage determines the operating mode. High speed operation is controlled by the windshield wiper/washer switch through the windshield wiper switch high signal circuit. The windshield wiper switch high signal circuit is supplied 12 volts by the wiper motor module and when the wiper/washer switch is turned to the HIGH position the windshield wiper switch high signal circuit is grounded through the switch ground circuit.
Reference Information
Schematic Reference
Connector End View Reference
Description and Operation
Wiper/Washer System Description and Operation
Electrical Information Reference
Scan Tool Reference
Control Module References for scan tool information
Circuit/System Verification
Ignition ON, verify wiper motor operation in all switch positions.
| ⇒ | If the wiper motor is inoperative in all modes, refer to Wiper Motor/Module Circuit Test. |
| ⇒ | If the wiper motor is inoperative in high or all low speed modes only, refer to Wiper Motor Switch Circuit Test. |
| ⇒ | If the wiper motor is inoperative in delay modes, low, or mist, but operates in wash mode, test or replace the turn signal/multifunction switch. |
Circuit/System Testing
Wiper Motor Switch Circuit Test
- Disconnect the X201, harness connectors at the windshield wiper switch.
- Test for less than 1.0 ohm of between the ground circuit terminal N and ground.
- Ignition ON, test for 11.0-13.0 volts between the 12-volt reference circuit terminal G and ground.
- Install a 3A fused jumper wire between the signal circuit terminal L and the 12-volt reference circuit terminal G. Ignition ON, verify the wiper motor operates in the wash mode.
- Install a 3A fused jumper wire between the signal circuit terminal H and ground. Ignition ON, verify the wiper motor operates in the high speed mode.
- If all circuits test normal, replace the turn signal/multifunction switch.
| ⇒ | If greater than the specified range, test the ground circuit for an open/high resistance. |
| ⇒ | If less than the specified range, test the 12-volt reference circuit for a short to ground or an open/high resistance. If the circuit tests normal, replace the wiper motor cover. |
| ⇒ | If the wiper motor does not operate, test the signal circuit for an open/high resistance or short to ground. If the circuit tests normal, refer to Wiper Motor/Module Circuit Test. |
| ⇒ | If the wiper motor does not operate, test the signal circuit for an open/high resistance. If the circuit tests normal, refer to Wiper Motor/Module Circuit Test. |
Wiper Motor/Module Circuit Test
- Ignition OFF, disconnect the harness connector at the windshield wiper motor cover.
- Test for less than 1.0 ohm between the ground circuit terminal M and ground.
- Verify that a test lamp illuminates between the B+ circuit terminal F and ground.
- Remove the wiper motor cover.
- Connect the harness connector at the windshield wiper motor cover.
- Connect a test lamp between the circuit board terminals T1 and T3.
- Ignition ON, wiper switch in low, verify the test lamp turns on for 15 seconds.
- If all circuits test normal, replace the windshield wiper motor.
| ⇒ | If greater than the specified range, test the ground circuit for an open/high resistance. |
| ⇒ | If the test lamp does not illuminate, test the B+ circuit for a short to ground or an open/high resistance. |
| ⇒ | If the test lamp does not turn on, replace the wiper motor cover. |
Component Testing
- Ignition OFF, disconnect the harness connectors at the winshield wiper switch.
- Test the resistance between terminals H and G. Rotate the wiper switch and compare the resistance readings to the values in the Windshield Wiper Switch Values table below for WASH, MIST, each DELAY and LOW speed.
| ⇒ | If the resistance is not within the specified range, replace the turn signal/multifunction switch. |
Switch Position | Resistance |
|---|---|
Off | Infinite |
Wash | 0.0-1.0 ohm |
Mist | 360-420 ohms |
Delay 1 | 0.980-1.40K ohms |
Delay 2 | 1.80-1.86K ohms |
Delay 3 | 3.00-3.60K ohms |
Delay 4 | 5.70-5.76K ohms |
Delay 5 | 8.40-8.46K ohms |
Low | 360-420 ohms |
Repair Instructions
Perform the Diagnostic Repair Verification after completing the diagnostic procedure.
