Diagnostic Test

WARNING: This page is about a different car, the 2015 Fiat 500. However, it is still accessible from the selected car via links, so may be relevant.

CHECK FOR AN ACTIVE DIAGNOSTIC TROUBLE CODE (DTC)
NOTE:
Prior to diagnosing this DTC, verify that the correct wattage bulbs are installed.
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.
CHECK THE (L77) LEFT FRONT PARK LAMP DRIVER CIRCUIT FOR AN OPEN IN THE HARNESS
1. Turn the ignition off.
2. Disconnect the Left Front Park/Turn Lamp harness connector.
3. Disconnect the BCM C1 harness connector.
4. Measure the resistance of the (L77) Left Front Park Lamp Driver circuit between the Left Front Park/Turn Lamp harness connector and the BCM C1 harness connector.
  Is the resistance below 5.0 Ohms?
  
  Yes
  - Go To 3
  No
  - Repair the open in the (L77) Left Front Park Lamp Driver circuit.
  - Perform the BODY VERIFICATION TEST. Refer to BODY CONTROL MODULE (BCM) - BODY VERIFICATION TEST - 500 - EXCEPT ELECTRIC .
CHECK THE (L71) LEFT REAR PARK LAMP DRIVER CIRCUIT FOR AN OPEN IN THE HARNESS
1. Disconnect the Left Tail Lamp Assembly harness connector.
2. Disconnect the BCM C2 harness connector.
3. Measure the resistance of the (L71) Left Rear Turn Signal Driver circuit between the Left Tail Lamp Assembly harness connector and the BCM C2 harness connector.
  Is the resistance below 5.0 Ohms?
  
  Yes
  - Go To 4
  No
  - Repair the open in the (L71) Left Rear Park Lamp Driver circuit.
  - Perform the BODY VERIFICATION TEST. Refer to BODY CONTROL MODULE (BCM) - BODY VERIFICATION TEST - 500 - EXCEPT ELECTRIC .
CHECK THE (Z910) GROUND CIRCUIT FOR AN OPEN IN THE HARNESS
1. Using a 12-volt test light connected to 12-volts, check the (Z910) Ground circuit at the Left Front Park/Turn Lamp harness connector.
  Does the test light illuminate brightly?
  
  Yes
  - Go To 5
  No
  - Repair the open in the (Z910) Ground circuit.
  - Perform the BODY VERIFICATION TEST. Refer to BODY CONTROL MODULE (BCM) - BODY VERIFICATION TEST - 500 - EXCEPT ELECTRIC .
CHECK THE (Z941) GROUND CIRCUIT FOR AN OPEN IN THE HARNESS
1. Using a 12-volt test light connected to 12-volts, check the (Z941) Ground circuit at the Left Tail Lamp Assembly harness connector.
  Does the test light illuminate brightly?
  
  Yes
  - Go To 6
  No
  - Repair the open in the (Z941) Ground circuit.
  - Perform the BODY VERIFICATION TEST. Refer to BODY CONTROL MODULE (BCM) - BODY VERIFICATION TEST - 500 - EXCEPT ELECTRIC .
CHECK THE BCM FOR CORRECT OPERATION AT THE LEFT FRONT PARK LAMP
1. Turn the ignition off.
2. Reconnect the BCM C1 and C2 harness connectors.
3. Connect a 12-volt test light between the (L77) Left Front Park Lamp Driver circuit and the (Z910) Ground circuit at the Left Front Park/Turn Lamp harness connector.
4. Turn the ignition on.
5. Turn the Left Turn Signal on.
  Does the test light blink on and off?
  
  Yes
  - Inspect the Park Lamp Bulb, replace if necessary. If OK, go to 7
  No
  - Replace the BCM in accordance with the Service Information. Refer to MODULE, BODY CONTROL, REMOVAL .
  - Perform the BODY VERIFICATION TEST. Refer to BODY CONTROL MODULE (BCM) - BODY VERIFICATION TEST - 500 - EXCEPT ELECTRIC .
CHECK THE BCM FOR CORRECT OPERATION AT THE LEFT REAR PARK LAMP
1. Connect a 12-volt test light between the (L71) Left Rear Park Lamp Driver circuit and the (Z941) Ground circuit at the Left Tail Lamp Assembly harness connector.
2. Turn the Left Turn Signal on.
  Does the test light blink on and off?
  
  Yes
  - Replace the Park Lamp Bulb in accordance with the Service Information. Refer to UNIT, FRONT LAMP, LOWER, REMOVAL UNIT, FRONT LAMP, UPPER, REMOVAL .
  - Perform the BODY VERIFICATION TEST. Refer to BODY CONTROL MODULE (BCM) - BODY VERIFICATION TEST - 500 - EXCEPT ELECTRIC .
  No
  - Replace the BCM in accordance with the Service Information. Refer to MODULE, BODY CONTROL, REMOVAL .
  - Perform the BODY VERIFICATION TEST. Refer to BODY CONTROL MODULE (BCM) - BODY VERIFICATION TEST - 500 - EXCEPT ELECTRIC .