GM Service Manual Online
For 1990-2009 cars only
Makes 🢒 Buick 🢒 2005 🢒 Century 🢒 Restraints 🢒 SIR 🢒 DTC B2608

Circuit Description

The body control module (BCM) illuminates RF turn signal lamp during daytime running lamps (DRL) operation in the day mode. The BCM applies steady power to the RF turn signal lamp which illuminates the RF turn signal lamp in a non flashing mode.

DTC Descriptor

This diagnostic procedure supports the following DTC:

DTC B2608 DRL Control Right Circuit High

Conditions for Running the DTC

The BCM must be commanding the RF turn signal lamp on.

Conditions for Setting the DTC
    • The BCM detects a short to battery positive voltage in the RF turn signal lamp supply voltage circuit or the RF turn signal switch signal circuit.
    • The condition above must be present for more than 20 seconds.

Action Taken When the DTC Sets

The BCM stores DTC B2608 in memory.

Conditions for Clearing the DTC
    • A current DTC B2608 will clear if the BCM no longer detects a short to battery positive voltage in RF turn signal lamp supply voltage circuit.
    • A history DTC B2608 will clear after 100 consecutive ignition cycles if the condition for the malfunction is no longer present.
    • The BCM receives a clear code command from the scan tool.

Diagnostic Aids
    • If the DTC B2608 is a history DTC, the fault may be intermittent. Refer to Testing for Intermittent Conditions and Poor Connections in Wiring Systems.
    • The following conditions may cause an intermittent malfunction to occur:
       - An intermittent short to battery positive voltage in the RF turn signal lamp supply voltage circuit or the RF turn signal switch signal circuit
       - The BCM is intermittently shorted to battery.

Step

Action

Yes

No

Schematic Reference: Exterior Lights Schematics

Connector End View Reference: Master Electrical Component List in Wiring Systems

1

Did you perform the Diagnostic System Check - Vehicle?

Go to Step 2

Go to Diagnostic System Check - Vehicle in Vehicle DTC Information

2
  1. Install a scan tool.
  2. Turn ON the ignition, with the engine OFF.
  3. With a scan tool, command the RF turn signal lamp control ON and OFF.

Does the RF turn signal lamp turn ON and OFF with each command?

Go to Diagnostic Aids

Go to Step 3

3

  1. Turn OFF the ignition.
  2. Disconnect the RF turn signal lamp.
  3. Turn ON the ignition, with the engine OFF.
  4. Using a test lamp connected to ground, probe the RF turn signal supply voltage circuit.

Does the test lamp illuminate?

Go to Step 4

Go to Step 6

4

Test the RF turn signal supply voltage circuit for a short to battery positive voltage. Refer to Circuit Testing and Wiring Repairs in Wiring Systems.

Did you find and correct the condition?

Go to Step 7

Go to Step 5

5

Test the RF turn signal switch signal circuit for a short to battery positive voltage. Refer to Circuit Testing and Wiring Repairs in Wiring Systems.

Did you find and correct the condition?

Go to Step 7

Go to Step 6

6

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

Did you complete the replacement?

Go to Step 7

--

7
  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