GM Service Manual Online
For 1990-2009 cars only

Circuit Description

The IPC monitors the ignition 0 voltage circuit, the ignition 1 voltage circuit, and the crank voltage circuit. The ignition 0 voltage circuit is active (circuit is high) when the ignition switch is in accessory, on, or start. The ignition 1 circuit is active (circuit is high) when the ignition switch is in on or start. The crank voltage circuit is active (circuit is high) when the ignition switch is in start.

Conditions for Running the DTC

The ignition is on or in the crank position.

Conditions for Setting the DTC

    â€¢ The IPC detects that the ignition 1 voltage circuit is active and the ignition 0 circuit is inactive.
    â€¢ The IPC detects that the crank voltage circuit is active and the ignition 0 voltage circuit is inactive.
    â€¢ The IPC detects that the crank voltage circuit is active and the ignition 1 voltage circuit is inactive.
    â€¢ One of the above conditions is present for greater than 0.3 seconds.

Action Taken When the DTC Sets

The IPC illuminates the SERVICE VEHICLE SOON indicator.

Conditions for Clearing the DTC

    â€¢ The current DTC clears when the conditions for setting the DTC are no longer present.
    â€¢ The history DTC clears after 100 malfunction free ignition cycles.
    â€¢ The IPC receives a clear code command from the scan tool.

Diagnostic Aids

    â€¢ Refer to Testing for Intermittent Conditions and Poor Connections in Wiring Systems.
    â€¢ The table below shows the ignition switch positions and the corresponding states of the circuits.

Ignition Switch Position

Ignition 0 Voltage Circuit

Ignition 1 Voltage Circuit

Crank Voltage Circuit

Off/Lock

Inactive

Inactive

Inactive

Accessory

Active

Inactive

Inactive

On

Active

Active

Inactive

Start

Active

Active

Active

Test Description

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

  1. Test the entire ignition voltage circuit, which includes the ignition switch and the fuses.

  2. Test the entire crank voltage circuit, which includes the ignition switch and the fuse.

  3. Test the entire ignition 1 voltage circuit, which includes the ignition switch and the fuse.

Step

Action

Value(s)

Yes

No

Schematic Reference: Instrument Cluster Schematics

1

Did you perform the Instrument Cluster Diagnostic System Check?

--

Go to Step 2

Go to Diagnostic System Check - Instrument Cluster

2

  1. Install a scan tool.
  2. Turn the ignition ON.
  3. With a scan tool, observe the Ignition 1 and the Ignition 0 parameters in the IPC Data list.

Does the scan tool display Active for both parameters?

--

Go to Step 3

Go to Step 5

3

  1. Turn ON the ignition, with the engine OFF.
  2. With a scan tool, observe the Crank parameter in the IPC Data list.

Does the scan tool display Inactive?

--

Go to Step 4

Go to Step 6

4

  1. Turn the ignition switch to accessory.
  2. With a scan tool, observe the Ignition 1 parameter in the IPC data list.

Does the scan tool display Inactive?

--

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

Go to Step 7

5

Test the inactive ignition voltage circuit for an open, a high resistance, or a short to ground. Refer to Circuit Testing and Wiring Repairs in Wiring Systems.

Did you find and correct the condition?

--

Go to Step 10

Go to Step 8

6

Test the crank voltage circuit of the IPC 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 10

Go to Step 8

7

Test the ignition 1 voltage circuit 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 10

Go to Step 8

8

Inspect for poor connections at the harness connector of the IPC. 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 10

Go to Step 9

9

Replace the IPC. Refer to Instrument Cluster Replacement .

Did you complete the replacement?

--

Go to Step 10

--

10

  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 reset?

--

Go to Step 2

System OK