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 DTC
1. Turn the ignition on.
2. With the scan tool, read DTCs and record on the repair order.
  Is the DTC active or pending?
  
  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. Refer to BODY CONTROL MODULE (BCM) - BODY VERIFICATION TEST - 500 - EXCEPT ELECTRIC .
FUEL LEVEL SENDING UNIT
1. Turn the ignition off.
2. Disconnect the Fuel Pump Module C1 harness connector.
3. Turn the ignition on.
4. With the scan tool, read DTCs.
  NOTE:
  The scan tool should display the P0463-FUEL LEVEL SENSOR 1 CIRCUIT HIGH DTC as active or pending with the harness connector unplugged
  
  Does the scan tool display as describe above?
  
  Yes
  - Replace the Fuel Level Sending Unit in accordance with the Service Information.
  - Perform the BODY VERIFICATION TEST. Refer to BODY CONTROL MODULE (BCM) - BODY VERIFICATION TEST - 500 - EXCEPT ELECTRIC .
  No
  - Go To 3
CHECK THE (N4) FUEL LEVEL SENSOR SIGNAL CIRCUIT FOR A SHORT TO GROUND
1. Turn the ignition off.
2. Disconnect the BCM C6 harness connector.
3. Check for continuity between ground and the (N4) Fuel Level Sensor Signal circuit at the Fuel Pump Module C1 harness connector.
  Is there continuity between ground and the (N4) Fuel Level Sensor Signal circuit?
  
  Yes
  - Repair the (N4) Fuel Level Sensor Signal circuit for a short to ground.
  - Perform the POWERTRAIN VERIFICATION TEST. Refer to POWERTRAIN VERIFICATION TEST, 16V .
  No
  - Go To 4
CHECK THE (N4) FUEL LEVEL SENSOR SIGNAL CIRCUIT FOR A SHORT TO THE (G109) FUEL LEVEL SENSE RETURN CIRCUIT
1. Check for continuity between the (G109) Fuel Level Sense Return circuit and the (N4) Fuel Level Sensor Signal circuit at the Fuel Pump Module C1 harness connector.
  Is there continuity between the (G109) Fuel Level Sense Return circuit and the (N4) Fuel Level Sensor Signal circuit?
  
  Yes
  - Repair the short between the (G109) Fuel Level Sense Return circuit and the (N4) Fuel Level Sensor Signal circuit.
  - Perform the BODY VERIFICATION TEST. Refer to BODY CONTROL MODULE (BCM) - BODY VERIFICATION TEST - 500 - EXCEPT ELECTRIC .
  No
  - Go To 5
BODY CONTROL MODULE (BCM)
1. Using the wiring diagram/schematic as a guide, inspect the wiring and connectors between the Fuel Pump Module and the BCM.
2. Look for any chafed, pierced, pinched, or partially broken wires.
3. Look for broken, bent, pushed out or corroded terminals. Verify that there is good pin to terminal contact in the Fuel Pump Module and the BCM harness connectors.
4. Perform any Service Bulletins that may apply.
  Were any problems found?
  
  Yes
  - Repair as necessary.
  - Perform the BODY VERIFICATION TEST. Refer to BODY CONTROL MODULE (BCM) - BODY VERIFICATION TEST - 500 - EXCEPT ELECTRIC .
  No
  - Replace the Body Control Module 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 .