• | 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. |
Circuit | Short to Ground | Open/High Resistance | Short to Voltage | Signal Performance |
---|---|---|---|---|
Windshield Washer Switch Signal | 6 8 | 8 | 1 | -- |
Windshield Wiper Motor Relay Coil Supply Voltage | B3715 00 | 2 | 6 | -- |
Windshield Wiper Switch High Signal | 6 | 4 | 1 | -- |
Windshield Wiper Switch Low Signal | B3922 00 | 3 | 1 | -- |
Windshield Wiper Motor Park Switch Signal | 5 | 5 | -- | -- |
Windshield Wiper Motor High Speed Control | 2 | 4 | -- | -- |
Windshield Wiper Motor Low Speed Control | 2 | 3 | -- | -- |
Windshield Wiper Motor Ground | -- | 2 | -- | -- |
Windshield Wiper Switch Ground | -- | 1 | -- | -- |
Wiper High Speed Relay Control | 7 | 4 | B3875 00 | -- |
Wiper Relay Ground | -- | 2 | -- | -- |
1. Wipers and washers inoperative all modes 2. Wipers inoperative all modes and washers work 3. Delay or low speed wipers inoperative 4. High speed wipers inoperative 5. Wipers do not park 6. Wipers always on 7. Wipers operate at high speed in the low speed mode 8. Washer malfunction |
Wiper Mist, Delay 1-5, and Low are all low speed wiper motor functions that are controlled by the body control module (BCM). When the wiper switch is placed in one of the LOW speed wiper modes, ground is applied through the switch contacts a series of internal resistors and the wiper switch low signal circuit to the BCM. In response to this signal, the BCM energizes the WPR relay by applying battery voltage through the wiper relay control circuit to the coil side of the relay. This allows battery positive voltage from the WPR fuse to flow through the switch input side of the WPR relay and out to the switch input side of the WIPER HI relay. Since the wiper high relay is de-energized and its switch contacts are normally closed to the low speed control circuit of the windshield wiper motor, the motor will operate at low speed.
When the wiper switch is placed in the HIGH speed position, ground is applied through the switch contacts and the wiper switch high signal circuit to the BCM indicating the wiper high speed request. The BCM then energizes WPR relay as stated above and the WIPER HI relay by applying ground through the control circuit to the coil side of the relay. With the wiper high relay energized and its switch contacts closed to the high speed control circuit of the wiper motor, the motor will operate at high speed.
• | A short to ground in the following circuits will open the WPR fuse: |
- | Ignition 1 voltage |
- | Windshield wiper motor relay coil supply voltage |
- | Windshield wiper switch high signal |
- | Windshield wiper motor low speed control |
- | Windshield wiper motor high speed control |
• | A short to B+ on any of the wiper/washer switch signal circuits will open the ground trace in the wiper switch. |
Wiper/Washer System Description and Operation
Control Module References for Scan Tool Information
⇒ | If one or more of the Wiper Delay Setting parameters are inoperative and the Windshield Wiper Switch low speed parameter functions, replace the turn signal/multifunction switch. |
⇒ | If the low speed parameter is inoperative, perform the Multifunction Switch Circuit/System Testing and/or the Multifunction Switch Component Test. |
⇒ | If not Active, perform the Multifunction Switch Circuit/System Testing and/or the Multifunction Switch Component Test. |
⇒ | If the Wiper Park Switch parameter is always Active or Inactive, perform the Wipers do not Park Circuit/System Testing. |
⇒ | If one or more of the commanded states do not work, perform the Wiper Motor tests in Circuit/System Testing and/or Component Test. |
⇒ | If greater than 15.0 ohms, test the ground circuit for an open/high resistance. If the circuit tests normal, test or replace the BCM. |
⇒ | If not Off, test the signal circuit terminal L for a short to ground. If the circuit tests normal, test or replace the BCM. |
⇒ | If not Inactive, test the signal circuit terminal K for a short to ground. If the circuit tests normal, test or replace the BCM. |
⇒ | If not Switch Fault, test the signal circuit for a short to voltage or an open/high resistance. If the circuit tests normal, test or replace the BCM. |
⇒ | If not Active, test the signal circuit for a short to voltage or an open/high resistance. If the circuit tests normal, test or replace the BCM. |
⇒ | If not Inactive, test the signal circuit terminal C for a short to ground. If the circuit tests normal, test or replace the BCM. |
⇒ | If not Active, test the signal circuit for an open/high resistance. If the circuit tests normal, replace the BCM. |
⇒ | If greater than 5.0 ohms, test the ground circuit for an open/high resistance. |
⇒ | If the test lamp is always ON, test the control circuit for a short to voltage. If the circuit tests normal, test or replace the BCM. |
⇒ | If the test lamp is always OFF, test the control circuit for a short to ground or an open/high resistance. If the circuit tests normal, test or replace the BCM. |
⇒ | If the test lamp is always ON, test the supply voltage circuit for a short to voltage. If the circuit tests normal, replace the WPR relay. |
⇒ | If the test lamp is always OFF, test the supply voltage circuit for a short to ground or an open/high resistance. If the circuit tests normal, replace the WPR relay. |
⇒ | If the test lamp is always ON, test the control circuit for a short to ground. If the circuit tests normal, test or replace the BCM. |
⇒ | If the test lamp is always OFF, test the control circuit for a short to voltage or an open/high resistance. If the circuit tests normal, test or replace the BCM. |
⇒ | If greater than 1.0 ohm, test the ground circuit for an open/high resistance. |
⇒ | If the test lamp is always ON, test the control circuit for a short to voltage. If the circuit tests normal, replace the WPR HI relay. |
⇒ | If the test lamp is always OFF, test the control circuit for a short to ground or an open/high resistance. If the circuit tests normal, replace the WPR HI relay. |
⇒ | If the test lamp is always ON, test the control circuit for a short to voltage. If the circuit tests normal, replace the WPR HI relay. |
⇒ | If the test lamp is always OFF, test the control circuit for a short to ground or an open/high resistance. If the circuit tests normal, replace the WPR HI relay. |
⇒ | If the resistance is not within the specified range, replace the turn signal/multifunction switch. |
⇒ | If the less than infinite, replace the turn signal/multifunction switch. |
⇒ | If greater than 5 ohm, replace the turn signal/multifunction switch. |
⇒ | If less than infinite, replace the turn signal/multifunction switch. |
⇒ | If greater than 5 ohm, replace the turn signal/multifunction switch. |
Important: If the switch tests open in any switch position other than Off, test the wiper/washer switch signal circuits for a short to voltage before replacing the switch.
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 |
⇒ | If the wiper motor is not in the low speed mode replace the motor. |
⇒ | If the wiper motor is not in the high speed mode replace the motor. |
Perform the Diagnostic Repair Verification after completing the diagnostic procedure.
• | Control Module References for BCM replacement, setup, and programming |