GM Service Manual Online
For 1990-2009 cars only
Makes 🢒 GMC_Truck 🢒 2003 🢒 Envoy - 2WD 🢒 Body and Accessories 🢒 Wipers/Washer Systems 🢒 DTC B3799

Circuit Description

The switch power circuit to the rear wiper/washer switch is a 12-volt reference supplied by the body control module. The rear wiper/washer switch is a series of resistors and the switch position is determined by the voltage of the rear wiper/washer switch signal circuit to the body control module. The rear wiper/washer switch has continuity at all times and the body control module expects a rear wiper/washer switch signal voltage in all switch positions including OFF.

Conditions for Running the DTC
    • Battery voltage must be between 9.0-16.0 volts.
    • The rear wiper/washer switch is active or inactive.

Conditions for Setting the DTC

The rear wiper/washer switch signal circuit is higher or lower than normal switch operation allows.

Action Taken When the DTC Sets
    • The DTC will be current for as long as the fault is present.
    • The rear wiper/washer system will be disabled for as long as the DTC is current.

Conditions for Clearing the DTC
    • The DTC status will change from current to history when the fault is no longer present.
    • A history DTC will be cleared after 100 error free ignition cycles.

Test Description

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

  1. This step verifies that the fault is current.

    2.

  2. This code may be set inadvertently.

    3.

  3. This step tests the resistance through the rear wiper switch. The measured resistance will be highest in the OFF position and reduce as the switch is turned from positions 1 through 3.

    4.

  4. If the code was set inadvertently, the new calibration files will have the code turned off.

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. Install a scan tool.
  2. Turn ON the ignition, with the engine OFF.
  3. Operate the rear wiper/washer switch through all the switch positions.
  4. With a scan tool, observe the requested rear wiper parameter.

Does the scan too indicate the correct requested rear wiper parameter in relation to the switch position?

--

Go to Step 3

Go to Step 4

3

  1. Using the scan tool clear the DTC.
  2. Operate the rear wiper/washer switch through all the switch positions.

Does the rear wiper/washer system operate normally?

--

System OK

Go to Step 11

4

  1. Disconnect the rear wiper/washer switch.
  2. Measure the resistance through the rear wiper/washer switch from the switch power circuit terminal to the signal circuit terminal.
  3. Operate the rear wiper/washer switch through the following switch positions:
    4. • OFF
    • 1
    • 2
    • 3

Does the resistance remain within the specified values from high to low as the switch is operated through the listed switch positions?

3100-1500 ohms

Go to Step 5

Go to Step 9

5

While measuring the resistance through the rear wiper/washer switch from the switch power circuit terminal to the signal circuit terminal press the wash switch.

Is the resistance near the specified value?

1270 ohms

Go to Step 6

Go to Step 9

6

Test the switch power circuit to the rear wiper/washer switch for an open, short to ground, or short to voltage. Refer to Circuit Testing and Wiring Repairs in Wiring Systems.

Did you find and correct the condition?

--

Go to Step 13

Go to Step 7

7

Test the rear wiper/washer switch signal circuit to the rear wiper switch for an open, short to ground, or short to voltage. Refer to Circuit Testing and Wiring Repairs in Wiring Systems.

Did you find and correct the condition?

--

Go to Step 13

Go to Step 8

8

Inspect for poor connections at the harness connector of the body control module. Refer to Circuit Testing and Wiring Repairs in Wiring Systems.

Did you find and correct the condition?

--

Go to Step 13

Go to Step 10

9

Inspect for poor connections at the harness connector of the rear wiper/washer switch. Refer to Circuit Testing and Wiring Repairs in Wiring Systems.

Did you find and correct the condition?

--

Go to Step 13

Go to Step 12

10

Replace the body control module and perform the programing procedure. Refer to Body Control Module Replacement and Body Control Module (BCM) Programming/RPO Configuration in Body Control System.

Did you complete the replacement?

--

Go to Step 13

--

11

Perform the programming procedure for the BCM. Refer to Body Control Module (BCM) Programming/RPO Configuration .

Did you complete the programming procedure?

--

Go to Step 13

--

12

Replace the rear wiper/washer switch.

Did you complete the replacement?

--

Go to Step 13

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13
  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