GM Service Manual Online
For 1990-2009 cars only
Makes 🢒 Chevrolet 🢒 2005 🢒 Uplander - 4WD 🢒 Brakes 🢒 Park Brake 🢒 DTC B3873

Circuit Description

The body control module (BCM) controls and monitors the windshield washer fluid pump control circuit. The BCM supplies battery positive voltage to the windshield washer fluid pump when commanded ON by the windshield wiper/washer switch. Ground is applied at all times from G200 to the windshield washer fluid pump.

DTC Descriptor

This diagnostic procedure supports the following DTC:

DTC B3873 Front Washer Relay Circuit

Conditions for Running the DTC
    • The ignition is ON.
    • The ignition voltage is between 9-16 volts.

Conditions for Setting the DTC

The BCM detects a short to ground, an open, or a short to battery positive voltage in the windshield washer pump control circuit.

Action Taken When the DTC Sets

The BCM will not activate the output.

Conditions for Clearing the DTC
    • The DTC will clear on current status after the condition for setting the fault is corrected.
    • A history DTC will clear after 100 consecutive ignition cycles without a fault present.
    • History and current DTCs can be cleared using a scan tool.

Diagnostic Aids

Perform a visual inspection for loose or poor connections at all related components. Refer to Testing for Intermittent Conditions and Poor Connections .

Step

Action

Yes

No

Schematic Reference: Wiper/Washer Schematics

Connector End View Reference: Master Electrical Component List

1

Did you perform the Diagnostic System Check - Vehicle?

Go to Step 2

Go to Diagnostic System Check - Vehicle

2
  1. Turn the ignition to the ON position.
  2. Press the windshield washer switch.

Does the windshield washer pump operate?

Go to Testing for Intermittent Conditions and Poor Connections

Go to Step 3

3
  1. Turn the ignition to the OFF position.
  2. Disconnect the windshield washer fluid pump.
  3. Using a test lamp connected to ground, probe the windshield washer pump control circuit at the harness connector of the windshield washer fluid pump.

Does the test lamp illuminate?

Go to Step 6

Go to Step 4

4
  1. Leave the test lamp connected.
  2. Turn the ignition to the ON position.
  3. Press the washer switch.

Does the test lamp illuminate?

Go to Step 5

Go to Step 7

5
  1. Turn the ignition to the OFF position.
  2. Using a test lamp, probe between the windshield washer pump control circuit and the windshield washer fluid pump ground circuit at the harness connector of the windshield washer fluid pump.
  3. Turn the ignition to the ON position.
  4. Press the washer switch.

Does the test lamp illuminate?

Go to Step 9

Go to Step 8

6

Test for a short to battery positive voltage in the windshield washer pump control circuit. Refer to Circuit Testing and Wiring Repairs .

Did you find and correct the condition?

Go to Step 11

Go to Step 10

7

Test for a short to ground or an open in the windshield washer pump control circuit. Refer to Circuit Testing and Wiring Repairs .

Did you find and correct the condition?

Go to Step 11

Go to Step 10

8

Repair a poor connection or an open in the windshield washer fluid pump ground circuit. Refer to Circuit Testing and Wiring Repairs .

Did you complete the repair?

Go to Step 11

--

9

Replace the windshield washer fluid pump. Refer to Washer Pump Replacement .

Did you complete the replacement?

Go to Step 11

--

10

Replace the body control module (BCM). Refer to Control Module References for replacement, setup, and programming.

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