Power Mode Mismatch

Power Mode Mismatch

Diagnostic Instructions

* Perform the Diagnostic System Check - Vehicle prior to using this diagnostic procedure. Initial Inspection and Diagnostic Overview
* Review Strategy Based Diagnosis for an overview of the diagnostic approach.
* Diagnostic Procedure Instructions provides an overview of each diagnostic category.

Diagnostic Fault Information






Circuit/System Verification

With a scan tool, access Body Control Module, Power Mode data display list and compare all parameters listed with the corresponding ignition key position. The PMM Power Mode Parameters table below illustrates the correct state of these input parameters (circuits) in correspondence to the ignition switch position. The circuits which the individual parameters are related to are in parentheses.





If any parameters are incorrect in any key position, refer to the Circuit/System Testing or Component Testing.

Circuit/System Testing

Important: You must perform the Circuit/System Verification before proceeding with Circuit/System Testing.

1. Inspect the Ign Switch fuse for open.

^ If the fuse is open, test the circuits listed below for a short to ground:

* Ignition switch B+
* Accessory voltage
* Off/Run crank voltage
* Ignition 1 voltage

^ If all circuits test normal, replace the BCM.

2. Ignition OFF, disconnect the harness connector at the ignition switch.
3. Ignition ON, verify that a test lamp illuminates between the ignition switch B+ circuit terminal 2 and ground.

^ If the test lamp does not illuminate, test the B+ circuit for an open/high resistance.

Important: The ignition switch component test must be preformed before proceeding with this test to verify the integrity of the switch.

4. Ignition OFF, disconnect X2 and X4 harness connectors at the BCM.
5. Ignition key out, test for less than 1-volt between the circuit terminals listed below and ground:

* Accessory voltage terminal C8
* Ignition 1 voltage terminal D3
* Off/Run/Crank voltage terminal 56

^ If greater than the specified range, test the circuit for a short to voltage.

6. Test for less than 1 ohm between the BCM terminals and the ignition switch terminals listed below:

* Accessory voltage terminal C8 and 4
* Ignition 1 voltage terminal D3 and 3
* Off/Run/Crank voltage terminal 56 and 5

^ If greater than the specified range, test the circuit for an open/high resistance.

7. If all circuits test normal, replace the BCM.

Component Testing

Ignition Switch

Using the Resistance Test below, check the resistance between the pins of the ignition switch listed in each switch position listed.

If any reading is other than specified, replace the ignition switch.






Repair Instructions

Perform the Diagnostic Repair Verification after completing the diagnostic procedure. Verification Tests

* Ignition and Start Switch Replacement