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. With the scan tool, read Instrument Panel Cluster (IPC) DTCs and record on the repair order.
  Is the DTC active?
  
  Yes
  - Go To 2
  No
  - Go To 7
CHECK THE TURBO BOOST GAUGE CONNECTOR
1. Turn the ignition off.
2. Check the Turbo Boost Gauge harness connector for signs of water intrusion, corrosion, pushed out or bent terminals, correct pin tension and properly seated.
  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
  - Go To 3
CHECK THE (G5) FUSED IGNITION SWITCH OUTPUT (RUN - START) CIRCUIT FOR AN OPEN OR HIGH RESISTANCE
1. Disconnect the Turbo Boost Gauge harness connector.
2. Turn the ignition on.
3. With a test light connected to ground, check the (G5) Fused Ignition Switch Output (Run - Start) circuit at the Turbo Boost Gauge harness connector.
  NOTE:
  The test light must illuminate brightly. Compare the brightness to that of a direct connection to the battery.
  
  Does the test light illuminate brightly?
  
  Yes
  - Go To 5
  No
  - Repair the (G5) Fused Ignition Switch Output (Run - Start) circuit for an open or high resistance.
  - Perform the BODY VERIFICATION TEST. Refer to BODY CONTROL MODULE (BCM) - BODY VERIFICATION TEST - 500 - EXCEPT ELECTRIC .
CHECK THE (D500) LIN BUS CIRCUIT FOR AN OPEN OR HIGH RESISTANCE
1. Turn the ignition off.
2. Disconnect the Instrument Cluster harness connector.
3. Measure the resistance of the (D500) LIN Bus circuit between the Instrument Cluster harness connector and the Turbo Boost Gauge harness connector.
  Is the resistance below 3.0 Ohms?
  
  Yes
  - Go To 5
  No
  - Repair the (D500) LIN Bus circuit for an open or high resistance.
  - Perform the BODY VERIFICATION TEST. Refer to BODY CONTROL MODULE (BCM) - BODY VERIFICATION TEST - 500 - EXCEPT ELECTRIC .
CHECK THE (G134) GAUGE CLUSTER RETURN CIRCUIT FOR AN OPEN OR HIGH RESISTANCE
1. Measure the resistance of the (G134) Gauge Cluster Return circuit between the Instrument Cluster harness connector and the Turbo Boost Gauge harness connector.
  Is the resistance below 3.0 Ohms?
  
  Yes
  - Replace the Turbo Booster Gauge in accordance with the Service Information. Refer to GAUGE, BOOST, REMOVAL .
  - Perform the BODY VERIFICATION TEST. Refer to BODY CONTROL MODULE (BCM) - BODY VERIFICATION TEST - 500 - EXCEPT ELECTRIC .
  No
  - Repair the (G134) Gauge Cluster Return circuit for an open or high resistance.
  - Perform the BODY VERIFICATION TEST. Refer to BODY CONTROL MODULE (BCM) - BODY VERIFICATION TEST - 500 - EXCEPT ELECTRIC .
CHECK THE TURBO BOOSTER GAUGE
1. Replace the Turbo Booster Gauge in accordance with the Service Information. Refer to GAUGE, BOOST, REMOVAL .
2. Perform the BODY VERIFICATION TEST. Refer to BODY CONTROL MODULE (BCM) - BODY VERIFICATION TEST - 500 - EXCEPT ELECTRIC .
  Did the DTC return?
  
  Yes
  - Replace the Instrument Panel Cluster (IPC) in accordance with the Service Information. Refer to REMOVAL .
  - Perform the BODY VERIFICATION TEST. Refer to BODY CONTROL MODULE (BCM) - BODY VERIFICATION TEST - 500 - EXCEPT ELECTRIC .
  No
  - Test complete.
CHECK THE WIRING AND CONNECTORS
1. The conditions necessary to set the DTC are not present at this time.
2. Using the schematics as a guide, inspect the wiring and connectors specific to this circuit. Wiggle the wiring and connectors while checking for shorted and open circuits.
3. Check all related splices and connectors for signs of water intrusion, corrosion, pushed out or bent terminals, and correct pin tension.
4. Check for 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
  - Test complete.