GM Service Manual Online
For 1990-2009 cars only
Makes 🢒 Isuzu 🢒 2005 🢒 Ascender - 4WD 🢒 DTC 🢒 DTC B2697

Circuit Description

The headlamp washer switch signal circuit is supplied a 12-volt reference through a resistor then monitored within the body control module (BCM). The headlamp washer switch is open when in an inactive state. When the headlamp washer switch is activated the signal circuit is closed to ground. When the headlamp washer switch signal circuit is closed to ground the reference voltage is dropped across the resistor within the BCM. The low voltage on the headlamp washer switch signal circuit indicates to the BCM the switch status is active.

DTC Descriptor

This diagnostic procedure supports the following DTC:

DTC B2697 Headlamp Washer Request Circuit

Conditions for Running the DTC
    • Battery voltage must be between 9-16 volts.
    • The headlamp washer switch is active.

Conditions for Setting the DTC

The headlamp washer switch signal to the BCM is low longer than 10 seconds.

Action Taken When the DTC Sets
    • The DTC will be current for as long as the fault is present.
    • The headlamp washers will be disabled for as long as the DTC is current.

Conditions for Clearing the DTC
    • The DTC status will change form 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 step verifies the switch input to the BCM.

    3.

  3. This step determines if the fault is in the headlamp washer switch. If the switch input to the BCM changes to an inactive state when disconnected the switch contacts are stuck or shorted to ground.

Step

Action

Yes

No

Schematic Reference: Wiper/Washer Schematics

Connector End View Reference: Wiper/Washer Connector End Views

1

Did you perform the Diagnostic System Check - Vehicle?

Go to Step 2

Go to Diagnostic System Check - Vehicle

2

  1. Install a scan tool.
  2. Turn ON the ignition, with the engine OFF.
  3. With a scan tool, observe the Headlamp Washer Switch parameter in the body control module (BCM) inputs data list.

Does the scan tool display OFF?

Go to Step 3

Go to Step 4

3

  1. Activate the headlamp washer switch.
  2. With the scan tool, observe the Headlamp Washer Switch parameter.

Does the headlamp washer switch parameter change state?

Go to Testing for Intermittent Conditions and Poor Connections

Go to Step 4

4

  1. Turn OFF the ignition.
  2. Disconnect the headlamp washer switch.
  3. Turn ON the ignition, with the engine OFF.
  4. With a scan tool, observe the Headlamp Washer Switch parameter.

Does the scan tool display OFF?

Go to Step 7

Go to Step 5

5

Test the signal circuit of the headlamp washer switch for a short to ground. Refer to Circuit Testing and Wiring Repairs .

Did you find and correct the condition?

Go to Step 10

Go to Step 6

6

Inspect for poor connections at the harness connector of the BCM. Refer to Testing for Intermittent Conditions and Poor Connections and Connector Repairs .

Did you find and correct the condition?

Go to Step 10

Go to Step 8

7

Inspect for poor connections at the harness connector of the headlamp washer switch. Refer to Testing for Intermittent Conditions and Poor Connections and Connector Repairs .

Did you find and correct the condition?

Go to Step 10

Go to Step 9

8

Replace the BCM. Refer to Control Module References for replacement, setup, and programming.

Did you complete the replacement?

Go to Step 10

--

9

Replace the headlamp washer switch.

Did you complete the replacement?

Go to Step 10

--

10
  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