B2121-15

B2121-15-IGNITION RUN CONTROL 1 - CIRCUIT SHORT TO BATTERY OR OPEN

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





Theory of Operation

The Body Control Module (BCM) receives the network communication message from the Radio Frequency (RF) Hub indicating run operation is requested. The BCM provides a voltage output through the ignition run relay control circuit, which connects to the coil side of the Ignition Run Relay.

- When Monitored:
With the Ignition Run Relay off.

- Set Condition:
When the Body Control Module (BCM) detects a high condition on the Ignition Run Relay Control circuit.





Diagnostic Test

1. CHECK FOR AN ACTIVE DTC
1. Turn the ignition on.
2. With the scan tool, read DTCs.

Does the scan tool display this DTC as active?

Yes

- Go To 2

No

- Test complete, the condition or conditions that originally set this DTC are not present at this time. Using the wiring diagrams as a guide, check all related splices and connectors for signs of water intrusion, corrosion, pushed out or bent terminals, and correct pin tension.
- Perform the BODY VERIFICATION TEST. Body Verification Test .

2. CHECK THE IGNITION RUN RELAY FOR CORRECT OPERATION
1. Turn the ignition off.
2. Remove the Ignition Run Relay and substitute it with a known good relay.
3. Turn the ignition on.
4. With the scan tool, read DTCs.

Does the scan tool display this DTC as active?

Yes

- Go To 3

No

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

3. CHECK THE (K619) IGNITION RUN RELAY CONTROL CIRCUIT FOR A SHORT TO VOLTAGE
1. Turn the ignition off.
2. Remove the Ignition Run Relay.
3. Using a 12-volt test light connected to ground, check the (K619) Ignition Run Relay Control circuit.

Does the test light illuminate brightly?

Yes

- Repair the short to voltage in the (K619) Ignition Run Relay Control circuit.
- Perform the BODY VERIFICATION TEST. Body Verification Test .

No

- Go To 4

4. CHECK THE (K619) IGNITION RUN RELAY CONTROL CIRCUIT FOR AN OPEN
1. Disconnect the BCM E harness connector.
2. Measure the resistance of the (K619) Ignition Run Relay Control circuit between the PDC and the BCM E harness connectors.

Is the resistance below 5.0 Ohms?

Yes

- Replace the Body Control Module (BCM). Body Control Module - Removal.
- Perform the BODY VERIFICATION TEST. Body Verification Test .

No

- Repair the open in the (K619) Ignition Run Relay Control circuit.
- Perform the BODY VERIFICATION TEST. Body Verification Test .