Circuit Description
The Body Control Module (BCM) 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.
See the table in Diagnostic Aids.
Conditions for Running the DTC
The ignition is in on or crank.
Conditions for Setting the DTC
| • | The BCM detects that the ignition 1 voltage circuit is active and the ignition 0 circuit is inactive. |
| • | The BCM detects that the crank voltage circuit is active and the ignition 0 voltage circuit is inactive. |
| • | The BCM detects that the crank voltage circuit is active and the ignition 1 voltage circuit is inactive. |
| • | One of the above conditions is present for greater than 0.3 seconds. |
Action Taken When the DTC Sets
The SERVICE VEHICLE SOON indicator is illuminated .
Conditions for Clearing the DTC
| • | The current DTC clears when the conditions for setting the DTC are no longer present. |
| • | The history DTC clears after 100 malfunction free ignition cycles. |
Diagnostic Aids
| • | Refer to Testing for Intermittent Conditions and Poor Connections in Wiring Systems. |
| • | 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.
-
Test the entire ignition voltage circuit, which includes the ignition switch and the fuses.
-
Test the entire crank voltage circuit, which includes the ignition switch and the fuse.
-
Test the entire ignition 1 voltage circuit, which includes the ignition switch and the fuse.
Step | Action | Value(s) | Yes | No |
|---|---|---|---|---|
Schematic Reference: Body Control System Schematics | ||||
1 | Preform a Diagnostic System Check for the system exhibiting symptoms. Did you perform the Diagnostic System Check? | -- | Go to Step 2 | Go to the Diagnostic System Check for the system exhibiting symptoms |
2 |
Does the scan tool display Active for both parameters? | -- | Go to Step 3 | Go to Step 5 |
3 |
Does the scan tool display Inactive? | -- | Go to Step 4 | Go to Step 6 |
4 |
Does the scan tool display Inactive? | -- | Go to Testing for Intermittent Conditions and Poor Connections in Wiring Systems | Go to Step 7 |
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 | |
Test the crank voltage circuit of the BCM 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 | |
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 BCM. 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 |
Important:: Set up new BCM. Refer to Body Control Module (BCM) Programming/RPO Configuration Replace the BCM. Refer to Body Control Module Replacement . Did you complete the replacement? | -- | Go to Step 10 | -- |
10 |
Does the DTC reset? | -- | Go to Step 2 | System OK |
