B2140

B2140-IGNITION START (REMOTE START) CONTROL CIRCUIT HIGH





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

Theory of Operation

The family of B2100 Diagnostic Trouble Codes (DTCs) typically describes ignition performance related faults. These are often caused by a contradiction of switch status information. For example, if an Electronic Control Unit (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) will set this DTC within 500ms if the (F26) Ignition Switch Output (Start) circuit is shorted to voltage.





1. CHECK FOR ACTIVE DTC
1. Turn the ignition on.
2. 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. STARTER RELAY
1. Turn the ignition off.
2. Remove the Starter Relay.
3. Turn the ignition on.
4. With the scan tool, read the active FCM DTCs.

Does the scan tool display this DTC as active?

Yes

- Go To 4

No

- Replace the Starter Relay.
- Perform the BODY VERIFICATION TEST. Body Verification Test.

3. ENGINE CONTROL MODULE (ECM)
1. Turn the ignition off.
2. Disconnect the ECM C2 harness connector.
3. Turn the ignition on.
4. With the scan tool, read the active FCM DTCs.

Does the scan tool display this DTC as active?

Yes

- Go To 4

No

- Replace the Engine Control Module.
- Perform the ECM VERIFICATION TEST. Powertrain Verification Test.

4. (F26) IGNITION SWITCH OUTPUT (START) CIRCUIT SHORTED TO VOLTAGE




1. Turn the ignition off.
2. Disconnect the FCM C1 harness connector.
3. Turn the ignition on.
4. Measure the voltage of the (F26) Ignition Switch Output (Start) circuit at the FCM C1 harness connector.

Is the voltage above 10.0 Volts?

Yes

- Repair the (F26) Ignition Switch Output (Start) circuit for a short to voltage.
- Perform the BODY VERIFICATION TEST. Body Verification Test.

No

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