FREE REPAIR MANUALS & LABOR GUIDES 1982-2013 Vehicles
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B2105






B2105-IGNITION UNLOCK RUN/START CONTROL CIRCUIT HIGH





For a complete wiring diagram Refer to Diagrams/Electrical.

- When Monitored:

With the ignition on or off and with the FCM awake.

- Set Condition:

The Front Control Module will set this DTC within 2 seconds if the ignition unlock run/start circuit voltage is not what the expected value should be.





Diagnostic Test

1.CHECK FOR ACTIVE DTC

With the scan tool, read the active DTC's.

Cycle the ignition switch from off to on, leaving the ignition on for a minimum of 90 seconds then turn the ignition off.

With the scan tool, read the active DTC's.

Does the scan tool display this DTC as active?

Yes

- Go To 2

No

- If the DTC is stored, check for an intermittent condition. Visually inspect the related wiring harness connectors. Look for broken, bent, pushed out, or corroded terminals.

2.(F902) IGNITION UNLOCK RUN START CIRCUIT SHORTED TO VOLTAGE





Disconnect the Shifter Lever Assembly harness connector.

Cycle the ignition switch from off to on then back to off.

NOTE: The ignition switch must be in the off position when performing the following step.

Using a 12-volt test light connected to ground, check the (F902) Ignition Unlock Run Start circuit.

Does the test light illuminate brightly?

Yes

- Repair the (F902) Ignition Unlock Run Start circuit for a short to voltage.
- Perform BODY VERIFICATION TEST - VER 1. Body Verification Test

No

- Go To 3

3.SHIFTER LEVER ASSEMBLY





Turn the ignition on.

With the test light still connected from the previous step, check the (F902) Ignition Unlock Run Start circuit.

Does the test light illuminate brightly?

Yes

- Replace the Shifter Lever Assembly.
- Perform BODY VERIFICATION TEST - VER 1. Body Verification Test

No

- Go To 4

4.(F902) IGNITION UNLOCK RUN START CIRCUIT OPEN





Turn the ignition off.

Remove the FCM from the IPM.

Measure the resistance of the (F902) Ignition Unlock Run Start circuit between the Shifter Lever Assembly and the FCM-PDM connector.

Is the resistance below 5.0 ohms?

Yes

- Inspect the wiring and connectors for damage or shorted circuits. If ok, replace and program the Front Control Module.
- Perform BODY VERIFICATION TEST - VER 1. Body Verification Test

No

- Repair the (F902) Ignition Unlock Run Start circuit for an open.
- Perform BODY VERIFICATION TEST - VER 1. Body Verification Test