Diagnostic Test

TEST FOR INTERMITTENT CONDITION
1. Turn the ignition on.
2. Using a scan tool, record and erase Diagnostic Trouble Codes (DTCs).
3. Operate the Rear Window Defogger switch several times.
4. Cycle the ignition from on to off three times and leave on.
5. Using a scan tool, read DTCs.
  Does the scan tool display: B106C-REAR DEFROST CONTROL CIRCUIT HIGH?
  
  Yes
  - Go to step 2
  No
  - The conditions that caused this code to set are not present at this time. Using the wiring diagram/schematic as a guide, inspect the wiring and connectors.
  - Perform the BODY VERIFICATION TEST. See DTC-Based Diagnostics/MODULE, Front Control (FCM) - Standard Procedure .
CHECK FOR A SHORTED REAR WINDOW DEFOGGER RELAY
1. Turn the ignition off.
2. Install a known good relay in place of the Rear Window Defogger Relay.
3. Turn the ignition on.
4. Using a scan tool, erase DTCs.
5. Operate the Rear Window Defogger Switch several times.
6. Cycle the ignition from on to off three times and leave on.
7. Using a scan tool, read DTCs.
  Does the scan tool display: B106C-REAR DEFROST CONTROL CIRCUIT HIGH?
  
  Yes
  - Go to step 3
  No
  - Replace the original Rear Window Defogger Relay in accordance with the Service Information.
  - Perform the BODY VERIFICATION TEST. See DTC-Based Diagnostics/MODULE, Front Control (FCM) - Standard Procedure .
CHECK (C115) DEFOGGER RELAY CONTROL CIRCUIT FOR A SHORT TO VOLTAGE

Fig 1: Checking Defogger Relay Control Circuit
Courtesy of CHRYSLER LLC
1. Turn the ignition off.
2. Remove the replacement Rear Window Defogger Relay.
3. Disconnect the FCM from the Front Control Module IPM 49-way connector.
4. Turn the ignition on.
5. Measure the Voltage of the (C115) Defogger Relay Control circuit between the Rear Window Defogger Relay connector and ground.
  Is there any Voltage present?
  
  Yes
  - Repair the (C115) Defogger Relay Control circuit for a short to Voltage.
  - Perform the BODY VERIFICATION TEST. See DTC-Based Diagnostics/MODULE, Front Control (FCM) - Standard Procedure .
  No
  - Replace the Front Control Module (FCM) in accordance with the Service Information.
  - Perform the BODY VERIFICATION TEST. See DTC-Based Diagnostics/MODULE, Front Control (FCM) - Standard Procedure .