| Table 1: | Normal Device Power Moding |
| Table 2: | Code Setting Criteria (Fault) for Device Power Moding |
Circuit Description
Class 2 communications will not start until the vehicle systems on power mode has been identified. Three discrete wires from the ignition switch contacts are monitored by the Body Control Module (BCM) in order to determine the present power mode (ignition switch position). The BCM communicates the system power mode to all Class 2 modules on the Class 2 bus.
Conditions for Running the DTC
The Body Control Module must be powered.
Conditions for Setting the DTC
One of the three monitored ignition switch circuits has malfunctioned.
Action Taken When the DTC Sets
The BCM implements default actions for each ignition switch position when faults are detected.
Conditions for Clearing the MIL/DTC
The power moding malfunction must be corrected.
Diagnostic Aids
| • | The following may cause an intermittent: |
| - | Damaged terminal |
| - | Backed out terminal |
| - | Poor terminal tension |
| - | Chafed wire |
| - | Broken wire inside the insulation |
| • | When diagnosing for an intermittent short or an open, manipulate the wire harness while watching the test equipment for changes. |
Key Position | ACCESSORY Power | IGN 1 Power | IGN 0 Power |
|---|---|---|---|
OFF | Inactive | OFF | OFF |
ACCESSORY | Active | OFF | ON |
ON | Active | ON | ON |
Key Position | ACCESSORY Power | IGN 1 Power | IGN 0 Power |
|---|---|---|---|
OFF | Inactive | ON | OFF |
ACCESSORY | Active | OFF | OFF |
ON | Active | ON | OFF |
Step | Action | Value(s) | Yes | No |
|---|---|---|---|---|
1 | Did you perform the Body Control Module Diagnostic System Check? | -- | Go to Step 2 | |
2 |
Do all of the ignition switch input parameters display ON or Active? | -- | Go to Step 6 | Go to Step 3 |
3 | Test the ignition switch circuits that displayed inactive or OFF on the scan tool for an open or short to ground. Refer to Circuit Testing and Wiring Repairs in Wiring Systems. Did you find and correct the condition? | -- | Go to Step 12 | Go to Step 4 |
4 | Check for poor connections at the Body Control Module. 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 12 | Go to Step 5 |
5 | Check for poor connections at the ignition switch. 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 12 | Go to Step 11 |
6 |
Do all of the ignition switch input parameters of the ignition switch display Inactive or OFF? | -- | Go to Step 7 | Go to Step 8 |
7 |
Does the ignition switch Ign 1and Ign 0 input parameters display OFF and the Accessory Power input parameter display Active? | -- | Go to Step 10 | Go to Step 11 |
8 | Test the Ignition switch circuit(s) that displayed Active or ON in Step 6 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 12 | Go to Step 9 |
9 |
Did the test lamp illuminate? | -- | Go to Step 10 | Go to Step 11 |
10 | Replace the ignition switch. Refer to Ignition and Start Switch Replacement in Instrument Panel, Gauges and Console. Did you complete the replacement? | -- | Go to Step 12 | -- |
11 |
Did you complete the replacement and the set up procedure? | -- | Go to Step 12 | -- |
12 | Operate the system in order to verify the repair. Did you find and correct the condition? | -- | System OK | Go to Step 2 |
