GM Service Manual Online
For 1990-2009 cars only

DTC B2973 Door Key Switch Circuit Low Envoy Only


Object Number: 357916  Size: MF
Body Control Module Components
Body Control System Schematics
Handling ESD Sensitive Parts Notice
Body Control System Connector End Views

Circuit Description

The body control module (BCM) monitors CKT 262 for the content theft system. The BCM supplies an output to the LF and the RF mini-wedge door jamb switches when the BCM sense the output voltage low by turning the key in the door key switch, it disables the content theft system.

Conditions for Setting the DTC

    • CKT 262 is shorted to ground for more than 184 seconds.
    • The system voltage must be between 9.0 volts and 16.0 volts.
    • The above conditions must be met for 0.5 seconds.

Action Taken When the DTC Sets

    • If the short to ground occurs after the vehicle is secured, the content theft system will be disabled.
    • If the short to ground occurs before the vehicle is secured, the content system will not disable the system by turning the key in the door key switch.

Conditions for Clearing the MIL/DTC

    • The current DTC will clear immediately after the short to ground is corrected.
    • A history DTC will clear after 100 consecutive ignition cycles without a fault present.
    • History and current DTCs can be cleared using a scan tool.

Diagnostic Aids

    • Always diagnose the first DTC listed on the scan tool.
    • The scan tool must display DTC B2973 as a current code before performing diagnostics.
    • If a self-powered test lamp is not available, the same results may be obtained by connecting a test lamp to battery voltage and probing the ground circuit.
    • Perform a visual inspection for loose or poor connections at all related components.
    • Refer to Wiring Systems for intermittent or poor connections.

Test Description

The number(s) below refer to the step number(s) on the diagnostic table.

  1. This determines if the BCM is defective. Disconnecting the BCM connector will set other DTCs.

  2. The step determines if the left front mini-wedge (door jamb switch) is shorted to ground.

  3. This step determines if the right front mini-wedge (door jamb switch) is shorted to ground or if CKT 262 is shorted to ground.

Step

Action

Value(s)

Yes

No

1

Was the BCM Diagnostic System Check performed?

--

Go to Step 2

Go to Diagnostic System Check - Body Control System

2

  1. Using a scan tool, monitor the current DTCs.
  2. Disconnect the BCM connector C3 (PPL).

Does the scan tool display DTC 2973 as current?

--

Go to Step 8

Go to Step 3

3

  1. Using a test lamp, backprobe (in order to prevent damage to the terminal) between CKT 262 (LT GRN) cavity B3 and B+ at BCM connector C3.
  2. Disconnect the LF mini-wedge (door jamb switch).

Does the test lamp light?

--

Go to Step 4

Go to Step 6

4

With the test lamp still connected, disconnect the RF mini-wedge (door jamb switch).

Does the test lamp light?

--

Go to Step 7

Go to Step 5

5

Replace the RF mini-wedge.

Is the repair complete?

--

Go to Step 9

--

6

Replace the LF mini-wedge.

Is the repair complete?

--

Go to Step 9

--

7

Locate and repair CKT 262 (LT GRN) short to ground between the BCM connector C3 (PPL) and the LF/RF mini-wedge (door jamb switches).

Is the repair complete?

--

Go to Step 9

--

8

  1. Replace the BCM.
  2. Program the BCM with the proper calibrations.
  3. Perform the learn procedure.

Is the repair complete?

--

Go to Step 9

--

9

Clear the DTCs.

Is the repair complete?

--

Go to Diagnostic System Check - Body Control System

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