Diagnostic Test

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 step 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. See DTC-Based Diagnostics/MODULE, Front Control (FCM) - Standard Procedure .
A/C PRESSURE TRANSDUCER
1. Turn the ignition off.
2. Disconnect the A/C Pressure Transducer harness connector.
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 active DTCs.
  Does the scan tool display this DTC as active?
  
  Yes
  - Go to step 3
  No
  - Replace the A/C Pressure Transducer in accordance with the service information.
  - Perform the BODY VERIFICATION TEST. See DTC-Based Diagnostics/MODULE, Front Control (FCM) - Standard Procedure .
(F891) 5 VOLT SUPPLY CIRCUIT SHORTED TO GROUND

Fig 1: Checking 5 Volt Supply Circuit Shorted To Ground
Courtesy of CHRYSLER LLC
1. Turn the ignition off.
2. Disconnect the FCM C1 harness connector.
3. Measure the resistance between ground and the (F891) 5 Volt Supply circuit.
  Is the resistance below 1000.0 Ohms?
  
  Yes
  - Repair the (F891) 5 Volt Supply circuit for a short to ground.
  - Perform the BODY VERIFICATION TEST. See DTC-Based Diagnostics/MODULE, Front Control (FCM) - Standard Procedure .
  No
  - Go to step 4
(F891) 5 VOLT SUPPLY CIRCUIT SHORTED TO THE (C918) FCM SENSOR RETURN CIRCUIT

Fig 2: Checking 5 Volt Supply Circuit Shorted To Front Control Module Sensor Return Circuit
Courtesy of CHRYSLER LLC
1. Measure the resistance between the (F891) 5 Volt Supply circuit and the (C918) FCM Sensor Return circuit.
  Is the resistance below 1000.0 Ohms?
  
  Yes
  - Repair the (F891) 5 Volt Supply circuit for a short to the (C918) FCM Sensor Return circuit.
  - Perform the BODY VERIFICATION TEST. See DTC-Based Diagnostics/MODULE, Front Control (FCM) - Standard Procedure .
  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 the BODY VERIFICATION TEST. See DTC-Based Diagnostics/MODULE, Front Control (FCM) - Standard Procedure .