GM Service Manual Online
For 1990-2009 cars only
Makes 🢒 Oldsmobile 🢒 2001 🢒 Intrigue 🢒 Body and Accessories 🢒 Body Control System 🢒 DTC B1422

Circuit Description

The body control module (BCM) monitors the IGN0, IGN1 and the CRANK circuits from the ignition switch. The BCM uses the voltage state (B+ or 0) and the sequence of state changes to determine the power mode called for by the ignition switch.

Conditions for Running the DTC

The BCM must be powered and must detect a change in the ignition switch circuit states.

Conditions for Setting the DTC
    • The BCM detects an improper voltage on one of the ignition switch circuits.
    • The sequence of the change of the circuit is incorrect for the power mode.

Action Taken When the DTC Sets
    • The BCM stores the DTC to memory.
    • The BCM operates in a fail-safe power mode dependent on the last valid power mode detected and the state of the engine run flag data on the class 2 serial data communications circuits.
    • The other modules on the vehicle operate in a fail safe power mode dependent on the last valid power mode transmitted by the BCM and the state of the engine run flag on the class 2 serial data communications circuits.

Conditions for Clearing the DTC
    • A current DTC clears when the malfunction is no longer present.
    • A history DTC clears when the module ignition cycle counter reaches the reset threshold, without a repeat of the malfunction.

Step

Action

Yes

No

Schematic Reference: Body Control System Schematics

1

Preform the Diagnostic System Check for the system exhibiting the symptom. Refer to Control Module References .

Did you perform the Diagnostic System Check?

Go to Step 2

Go to Control Module References

2
  1. Install a scan tool.
  2. Leave the ignition switch OFF.
  3. With a scan tool, monitor the following in Body Control Module, Data Display, Inputs:
    4. • Ignition 0
    • Ignition 1
    • Crank

Does the scan tool indicate that all inputs are inactive?

Go to Step 3

Go to Step 7

3
  1. Install a scan tool.
  2. Turn the ignition switch to ACCESSORY.
  3. With a scan tool, monitor the following in Body Control Module, Data Display, Inputs:
    4. • Ignition 0
    • Ignition 1
    • Crank

Does the scan tool indicate that the Ignition 0 input is active?

Go to Step 4

Go to Step 9

4
  1. Install a scan tool.
  2. Turn the ignition switch to ON, with the engine OFF.
  3. With a scan tool, monitor the following in Body Control Module, Data Display, Inputs:
    4. • Ignition 0
    • Ignition 1
    • Crank

Does the scan tool indicate that the Ignition 0 and the Ignition 1 inputs are active?

Go to Step 5

Go to Step 9

5

Important: The engine may start in this step. Turn the engine OFF immediately after reviewing the input data.

  1. Install a scan tool.
  2. Turn the ignition switch to CRANK/START.
  3. With a scan tool, monitor the following in Body Control Module, Data Display, Inputs:
    4. • Ignition 0
    • Ignition 1
    • Crank

Does the scan tool indicate that the Ignition 0 and the Ignition 1 and the Crank inputs are active?

Go to Step 6

Go to Step 9

6

Were any of the ignition switch inputs active when they were not called for in the previous steps?

Go to Step 7

Go to Step 12

7
  1. Disconnect the ignition switch harness connector(s).
  2. Install a scan tool.
  3. With a scan tool, monitor the following in Body Control Module, Data Display, Inputs:
    4. • Ignition 0
    • Ignition 1
    • Crank

Does the scan tool indicate that any of the Ignition 0 and the Ignition 1 and the Crank inputs are active?

Go to Step 8

Go to Step 10

8
  1. Disconnect the BCM harness connectors.
  2. Test the suspect ignition switch input circuit(s) 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 15

Go to Step 12

9
  1. Disconnect the ignition switch connector(s).
  2. Install a 3A fused jumper between the suspect circuit(s) and an ignition switch B+ supply.
  3. With a scan tool, monitor the suspect circuit(s) in Body Control Module, Data Display, Inputs:

Does the scan tool indicate that the suspect circuit(s) is now active?

Go to Step 10

Go to Step 11

10

Inspect for poor connections at the ignition switch harness connector(s). 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 15

Go to Step 13

11
  1. Disconnect the BCM harness connectors.
  2. Test the suspect ignition switch input circuit(s) for a short to ground or an open. Refer to Circuit Testing and Wiring Repairs in Wiring Systems.

Did you find and correct the condition?

Go to Step 15

Go to Step 12

12

Inspect for poor connections at the BCM harness connector(s). 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 15

Go to Step 14

13

Replace the ignition switch. Refer to Ignition and Start Switch Replacement in Instrument Panel, Gages and Console.

Did you complete the replacement?

Go to Step 15

--

14

Important: Perform the set up procedure for the BCM.

Replace the BCM. Refer to Body Control Module Replacement .

Did you complete the replacement?

Go to Step 15

--

15
  1. Reconnect all components.
  2. Use the scan tool in order to clear DTCs.
  3. Operate the vehicle within the Conditions for Running the DTC as specified in the supporting text.

Does the DTC reset?

System OK

Go to Step 2