GM Service Manual Online
For 1990-2009 cars only
Makes 🢒 GMC_Truck 🢒 2002 🢒 GMC C Sierra - 2WD 🢒 Body and Accessories 🢒 Instrument Panel, Gages, and Console 🢒 DTC B2961

Circuit Description

The body control module (BCM) monitors the ignition key alarm switch. When the key is in the ignition, the ignition key alarm switch is closed and the signal circuit is low. When the key is not in the ignition, the ignition key alarm switch is open and the signal circuit is high.

Conditions for Running the DTC

The ignition is ON.

Conditions for Setting the DTC
    • The ignition 1 input is active and the key in ignition switch signal circuit is inactive and the signal circuit is high.
    • The conditions above must be present for more than 5 seconds.

Action Taken When the DTC Sets

The BCM stores DTC B2961 in memory.

Conditions for Clearing the DTC
    • The DTC becomes history when the fault is no longer present.
    • A history DTC will clear after 100 malfunction free warm-up cycle.
    • The BCM receives a clear code command from the scan tool.

Step

Action

Yes

No

Schematic Reference: Audible Warnings Schematics

1

Did you perform the Audible Warning Diagnostic System Check?

Go to Step 2

Go to Diagnostic System Check - Audible Warnings

2
  1. Install a scan tool.
  2. Turn the ignition ON, with the engine OFF.
  3. With the scan tool, observe the Key In Ignition parameter in the BCM data list.

Does the Key In Ignition parameter display Yes?

Go to Step 3

Go to Step 4

3
  1. Turn the ignition ON, with the engine OFF.
  2. Observe the Ignition 1 parameter in the BCM data list.
  3. Turn the ignition OFF.

Does the Ignition 1 parameter display ACTIVE with the ignition OFF?

Go to Step 7

Go to Step 11

4
  1. Turn the ignition OFF.
  2. Disconnect the BCM connector C2.
  3. Connect a test lamp between the key in ignition signal circuit and battery positive voltage.
  4. Place the key in the ignition.

Does the test lamp illuminate?

Go to Step 8

Go to Step 5

5

Test the key in ignition signal circuit for an open or for a high resistance. Refer to Circuit Testing and to Wiring Repairs in Wiring Systems.

Did you find and correct the condition?

Go to Step 12

Go to Step 6

6

Test the ground circuit of the ignition key alarm switch for an open or for a high resistance. Refer to Circuit Testing and to Wiring Repairs in Wiring Systems.

Did you find and correct the condition?

Go to Step 12

Go to Step 9

7

Test the ignition 1 voltage circuit for a short to voltage. Refer to Circuit Testing and to Wiring Repairs in Wiring Systems.

Did you find and correct the condition?

Go to Step 12

Go to Step 11

8

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

Did you find and correct the condition?

Go to Step 12

Go to Step 11

9

Inspect for poor connections at the harness connector of the ignition switch. Refer to Testing for Intermittent Conditions and Poor Connections and to Connector Repairs in Wiring Systems.

Did you find and correct the condition?

Go to Step 12

Go to Step 10

10

Replace the ignition key alarm switch. Refer to Ignition Switch Replacement - On Vehicle in Steering Wheel and Column.

Did you complete the replacement?

Go to Step 12

--

11

Important: Perform the set up procedure for the replacement BCM.

Replace the BCM. Refer to Body Control Module Replacement in Body Control System.

Did you complete the replacement?

Go to Step 12

--

12
  1. Use the scan tool in order to clear the DTCs.
  2. Operate the vehicle within the Conditions for Running the DTC.

Does the DTC reset?

Go to Step 2

System OK