B2124-IGNITION RUN CONTROL CIRCUIT OPEN





For a complete wiring diagram Refer to Section 8W.


  • When Monitored:

    With the ignition on.

  • Set Condition:

    The Front Control Module will set this DTC within 500ms if the (F921) or (F923) run relay control circuit voltage is open or shorted to ground.


Possible Causes
  
(F921) or (F923) RUN RELAY CONTROL CIRCUIT OPEN OR SHORTED TO GROUND
  
RUN RELAY
  
FRONT CONTROL MODULE
  



Diagnostic Test

1.CHECK FOR ACTIVE DTC





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






Does the scan tool display this DTC as active?

Yes
  • Go To 3


No

3.(F921) or (F923) RUN RELAY CONTROL CIRCUIT OPEN






NOTE: This circuit contains a diode. When checking resistance of this circuit the red ohmmeter lead must be connected to the run relay cavity (85) and the black ohmmeter lead must be connected to the FCM–PDM connector.




Is the resistance below 10.0 ohms?

Yes
  • Go To 4


No

4.(F921) RUN RELAY CONTROL CIRCUIT SHORTED TO GROUND



NOTE: This circuit contains a diode. When checking for a short to ground you must check both sides of the diode.




Is the resistance below 10.0 ohms?

Yes


No
  • Go To 5

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



NOTE: This circuit contains a diode. When checking for a short to ground you must check both sides of the diode.




Is the resistance below 10.0 ohms?

Yes


No
  • Inspect the wiring and connectors for damage or shorted circuits. If ok, replace and program the Front Control Module in accordance with the service information.
  • Perform BODY VERIFICATION TEST – VER 1. (Refer to BODY VERIFICATION TEST – VER 1).