B2100

B2100-IGNITION RUN/START INPUT CIRCUIT PERFORMANCE





For a complete wiring diagram, refer to the Wiring Information Electrical Diagrams.

Theory of Operation

The family of B2100 DTCs typically describes ignition performance related faults. These are often caused by a contradiction of switch status information. For example, if an ECU receives a bussed message indicating ignition switch position but the state of a hardwired ignition circuit indicates another switch position a B2100 series DTC would likely result.

These DTCs can be caused by a number of conditions including:

- loose connections
- missing or blown fuses
- faulty component
- vehicle no start or long crank time

Verify the proper operation of the starting system and verify that this DTC is active before proceeding with the diagnostic test.

- When Monitored:
With the ignition on.

- Set Condition:
The Front Control Module (FCM) does not receive the voltage input from the (F20) Fused Ignition Switch Output (Run-Start) circuit for 10 seconds.





1. CHECK FOR ACTIVE DTC

NOTE: Verify that Fuse #34 is installed in the Junction Block.

1. With the scan tool, read the active DTCs.
2. Cycle the ignition switch from off to on, leaving the ignition on for a minimum of 90 seconds.
3. With the scan tool, read the active DTCs.

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.
- Perform the BODY VERIFICATION TEST. Body Verification Test.

2. FRONT CONTROL MODULE (FCM)




1. Turn the ignition off.
2. Disconnect the IPM C2 harness connector.
3. Turn the ignition on.
4. Using a volt meter, measure for voltage on the (F20) Fused Ignition Switch Output (Run-Start) circuit at the IPM C2 harness connector.

Is current battery voltage present?

Yes

- Replace the Front Control Module.
- Perform the BODY VERIFICATION TEST. Body Verification Test.

No

- Go To 3

3. (A106) FUSED B+ CIRCUIT




1. Turn the ignition off.
2. Disconnect the Ignition Switch harness connector.
3. Using a 12-volt test light connected to ground, check for voltage on the (A106) Fused B+ circuit.

Does the test light illuminate brightly?

Yes

- Go To 4

No

- Go To 5

4. (F20) FUSED IGNITION SWITCH OUTPUT (RUN-START) CIRCUIT OPEN




1. Measure the resistance of the (F20) Fused Ignition Switch Output (Run-Start) circuit between the IPM C2 and Ignition Switch harness connectors.

Is the resistance above 10.0 Ohms?

Yes

- Repair the (F20) Fused Ignition Switch Output (Run-Start) circuit for an open.
- Perform the BODY VERIFICATION TEST. Body Verification Test.

No

- Replace the Ignition Switch.
- Perform the BODY VERIFICATION TEST. Body Verification Test.

5. (F20) FUSED IGNITION SWITCH OUTPUT (RUN-START) CIRCUIT AND (A106) FUSED B+ CIRCUIT




1. Using an ohm meter, measure for a short to ground on the (F20) Fused Ignition Switch Output (Run-Start) circuit and the (A106) Fused B+ circuit.

Is the resistance below 10K Ohms on either the (F20) or (A106) circuits?

Yes

- Repair the appropriate circuit for a short to ground.
- Perform the BODY VERIFICATION TEST. Body Verification Test.

No

- Repair the (A106) Fused B+ circuit for an open.
- Perform the BODY VERIFICATION TEST. Body Verification Test.