GM Service Manual Online
For 1990-2009 cars only

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

    â€¢ The ignition 0 voltage circuit is active, and the key in ignition signal circuit is inactive or high.
    â€¢ These conditions must be present for more than 0.3 seconds.

Action Taken When the DTC Sets

The BCM stores DTC B2965 in memory.

Conditions for Clearing the DTC

    â€¢ The DTC becomes history when the fault is no longer present.
    â€¢ A history DTC is cleared after 100 consecutive ignition cycles if the condition for the malfunction is no longer present.
    â€¢ The BCM receives the clear code command from the scan tool.

Step

Action

Values

Yes

No

Schematic Reference: Audible Warnings Schematics

1

Did you perform the Audible Warnings Diagnostic System Check?

--

Go to Step 2

Go to Diagnostic System Check - Audible Warnings

2

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

Does the Key In Ignition parameter display Yes?

--

Go to Step 3

Go to Step 4

3

  1. Turn OFF the ignition.
  2. Remove the key.
  3. Disconnect the BCM connector C1.
  4. Connect a test lamp between the ignition 0 voltage circuit and a good ground.

Does test lamp illuminate?

--

Go to Step 7

Go to Step 11

4

  1. Turn OFF the ignition.
  2. Disconnect the BCM connector C2.
  3. Connect a test lamp between the signal circuit of the ignition key alarm switch and battery positive voltage.
  4. Turn ON the ignition, with the engine OFF.

Does the test lamp illuminate?

--

Go to Step 8

Go to Step 5

5

Test the signal 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 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 0 voltage circuit for a short to battery 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 switch. Refer to Ignition and Start Switch Replacement .

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 as specified in the supporting text.

Does the DTC set?

--

Go to Step 2

System OK