GM Service Manual Online
For 1990-2009 cars only

Circuit Description

The rear wiper motor is supplied battery positive voltage and ground. The liftgate control module controls rear wiper motor operation through the rear wiper motor control circuit. The rear wiper motor control circuit is supplied a battery positive reference voltage by the rear wiper motor module and is pulse width modulated to ground by the liftgate control module. The duty cycle of the pulse width modulation determines the rear wiper motor operating mode.

Conditions for Running the DTC

Battery voltage must be between 9-16 volts.

Conditions for Setting the DTC

The rear wiper motor control circuit is shorted to voltage.

Action Taken When the DTC Sets

The rear wiper/washer system will be disabled for as long as the DTC is current.

Conditions for Clearing the DTC

    • The DTC will be current for as long as the fault is present and it will be latched for the respective ignition cycle.
    • A history DTC will be cleared after 100 error free ignition cycles.

Step

Action

Value(s)

Yes

No

Schematic Reference: Wiper/Washer Schematics

Connector End View Reference: Wiper/Washer Connector End Views

1

Did you perform the Wiper/Washer System Diagnostic System Check?

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Go to Step 2

Go to Diagnostic System Check - Wiper/Washer

2

  1. Turn ON the ignition, with the engine OFF.
  2. Attempt to operate the rear wiper motor through all of the operating modes.

Does the rear wiper motor operate normally?

--

Go to Testing for Intermittent Conditions and Poor Connections in Wiring Systems

Go to Step 3

3

  1. Disconnect the rear wiper motor connector.
  2. Connect a test lamp from the battery positive voltage supply circuit terminal in the harness connector to a good ground.

Does the test lamp illuminate?

--

Go to Step 4

Go to Step 8

4

Connect a test lamp from the battery positive voltage supply circuit terminal to the ground circuit terminal in the rear wiper motor harness connector.

Does the test lamp illuminate?

--

Go to Step 5

Go to Step 9

5

  1. Connect the rear wiper motor connector.
  2. Disconnect the liftgate control module connector.
  3. Using a DMM measure the voltage at the rear wiper motor control circuit terminal in the liftgate control module harness connector.

Is the voltage within the specified values?

10-14 V

Go to Step 6

Go to Step 7

6

Test the rear wiper motor control circuit for high resistance. Refer to Circuit Testing and Wiring Repairs in Wiring Systems.

Did you find and correct the condition?

--

Go to Step 14

Go to Step 12

7

Test the rear wiper motor control circuit for an open or short to ground. Refer to Circuit Testing and Wiring Repairs in Wiring Systems.

Did you find and correct the condition?

--

Go to Step 14

Go to Step 10

8

Repair the battery positive voltage circuit to the rear wiper motor. Refer to Wiring Repairs in Wiring Systems.

Did you complete the repair?

--

Go to Step 14

--

9

Repair the rear wiper motor ground circuit for an open or high resistance. Refer to Wiring Repairs in Wiring Systems.

Did you complete the repair?

--

Go to Step 14

--

10

Inspect for poor connections at the harness connector of the rear wiper motor. Refer to Testing for Intermittent Conditions and Poor Connections and Connector Repairs in Wiring Systems.

Did you find and correct the condition?

--

Go to Step 14

Go to Step 11

11

Replace the rear wiper motor. Refer to Rear Window Wiper Motor Replacement .

Did you complete the replacement?

--

Go to Step 14

--

12

Inspect for poor connections at the harness connector of the liftgate control module. Refer to Testing for Intermittent Conditions and Poor Connections and Connector Repairs in Wiring Systems.

Did you find and correct the condition?

--

Go to Step 14

Go to Step 13

13

Important: Perform the setup procedure for the liftgate control module.

Replace the liftgate control module. Refer to Liftgate Control Module Replacement in Body Rear End.

Did you complete the replacement?

--

Go to Step 14

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14

  1. Use the scan tool in order to clear the DTCs .
  2. Operate the system in order to verify the repair.

Does the DTC reset?

--

Go to Step 2

System OK