GM Service Manual Online
For 1990-2009 cars only
Makes 🢒 Generic 🢒 2005 🢒 Unit Repair 🢒 DTC 🢒 DTC B3608

Circuit Description

The steering wheel controls (SWC) is a resistor network with momentary contact switches. The contact switch corresponds with a specific resistor in the network. Each resistor has a different resistance value. When a switch is pressed, a voltage drop occurs in the resistor network producing a specific voltage value unique to the switch selected. This specific voltage value allows the radio to identify which switch was pressed. The radio responds just as if the corresponding radio front panel button had been pressed.

The radio supplies approximately 10 volts to the SWC switches on the 10 volt reference circuit. The specific voltage value from the switch returns to the radio on the steering wheel controls signal circuit.

DTC Descriptor

This diagnostic procedure supports the following DTC:

DTC B3608 Steering Wheel Control Entertainment Output Signal Circuit

This Vehicle has DTCs which include DTC Symptoms. For more information on DTC Symptoms, refer to DTC Symptom Description in Vehicle DTC Information.

DTC Symptom

DTC Symptom Descriptor

01

Short to Battery

Conditions for Running the DTC
    • The radio is in the ACCESSORY, RUN, or RAP power mode.
    • The system voltage is at least 9.0 volts and no more than 16.0 volts.
    • All the above conditions are present for greater than 50 ms.

Conditions for Setting the DTC

The following conditions are present for 50 ms or longer:

Action Taken When the DTC Sets

The steering wheel control switch functions are inoperative.

Conditions for Clearing the DTC
    • The conditions for setting the DTC are no longer present.
    • A history DTC clears after 100 malfunction free ignition cycles.
    • The radio receives the clear code command from the scan tool.

Test Description

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

  1. This step verifies that the DTC is still present.

    2.

  2. This step isolates the fault condition.

Step

Action

Yes

No

Schematic Reference: Radio/Audio System Schematics

Connector End View Reference: Entertainment Connector End Views

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 the scan tool, monitor the DTC Information for DTC B3608.

Does the scan tool indicate that DTC B3608 is current?

Go to Step 3

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

3

Test the steering wheel controls signal circuit from the SWC switch for a short to voltage. Refer to Circuit Testing and Wiring Repairs in Wiring Systems.

Did you find and correct the condition?

Go to Step 6

Go to Step 4

4

Inspect for poor connections at the harness connector of the radio. 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 6

Go to Step 5

5
  1. Replace the radio. Refer to Radio Replacement
  2. Perform the VIN relearn procedure with a scan tool. On the scan tool, go to Module Replacement/Setup in Vehicle Control Systems and select Radio.

Did you complete the replacement?

Go to Step 6

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6

Operate the system in order to verify the repair.

Did you correct the condition?

System OK

Go to Step 2