B2122

B2122-IGNITION RUN CONTROL CIRCUIT LOW





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

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 Totally Integrated Power Module (TIPM) will set this DTC within 500ms if the (F923) Run Relay Control circuit voltage is open or shorted to ground.





1. CHECK FOR ACTIVE DTC
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.

2. RUN RELAY
1. Turn the ignition off.
2. Install a substitute Run Relay in place of the original Run Relay.
3. Cycle the ignition switch from off to on, leaving the ignition on for a minimum of 90 seconds.
4. With the scan tool, read the DTCs.

Does the scan tool display this DTC as active?

Yes

- Go To 3

No

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

3. (F923) RUN RELAY CONTROL CIRCUIT OPEN




1. Turn the ignition off.
2. Disconnect the TIPM C1 harness connector.
3. Remove the Run Relay from the Rear Power Distribution Module.
4. Measure the resistance of the Run Relay Control circuit.

Is the resistance below 10K ohms?

Yes

- Go To 4

No

- Repair the (F923) Run Relay Control circuit for an open.
- Perform the BODY VERIFICATION TEST Body Verification Test.

4. (F923) RUN RELAY CONTROL CIRCUIT SHORTED TO GROUND




1. Measure the resistance between ground and the (F923) Run Relay Control circuit at the TIPM C1 harness connector.

Is the resistance below 10K ohms?

Yes

- Repair the (F923) Run Relay Control circuit for a short to ground.
- 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 TIPM.
- Perform the BODY VERIFICATION TEST Body Verification Test.