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.
  NOTE:
  Diagnose and repair any system voltage or 5-volt Sensor Reference DTCs before continuing with this test.
  
  Does the scan tool display this DTC as active?
  
  Yes
  - Go To 2
  No
  - Perform the INTERMITTENT CONDITION diagnostic procedure. Refer to INTERMITTENT CONDITION .
CHECK THE FTP SENSOR SUPPLY CIRCUIT FOR VOLTAGE
1. Turn the ignition off.
2. Disconnect the FTP Sensor harness connector.
3. Turn the ignition on.
4. Measure the voltage between ground and the FTP Sensor Supply circuit at the FTP Sensor harness connector.
  Is the voltage between 4.8 and 5.2 volts?
  
  Yes
  - Go To 3
  No
  - Go To 6
CHECK THE (N7) FTP SENSOR SIGNAL CIRCUIT FOR A SHORT TO GROUND
1. Disconnect the FTP Sensor harness connector.
2. With the scan tool, monitor the FTP Sensor voltage with the FTP Sensor harness connector disconnected.
  NOTE:
  The sensor voltage should be approximately 5.0 volts (plus or minus.1 volts) with the connector disconnected.
  
  Does the scan tool display the voltage as described above?
  
  Yes
  - Verify that there is good pin to terminal contact in the FTP Sensor and Powertrain Control Module connectors. Replace the FTP Sensor if no problems were found with the connectors. Refer to SENSOR, FUEL TANK PRESSURE, REMOVAL .
  - Perform the POWERTRAIN VERIFICATION TEST. Refer to POWERTRAIN VERIFICATION TEST .
  No
  - Go To 4
CHECK THE (N7) FTP SIGNAL CIRCUIT FOR A SHORT TO GROUND
1. Turn the ignition off.
2. Disconnect the PCM C1 harness connector.
3. Check for continuity between ground and the (N7) FTP Sensor Signal circuit at the FTP Sensor harness connector.
  Is there continuity between ground and the (N7) FTP Sensor Signal circuit?
  
  Yes
  - Repair the short to ground in the (N7) FTP Sensor Signal circuit.
  - Perform the POWERTRAIN VERIFICATION TEST. Refer to POWERTRAIN VERIFICATION TEST .
  No
  - Go To 5
CHECK FOR THE (N7) FTP SENSOR SIGNAL CIRCUIT SHORTED TO THE FTP SENSOR RETURN CIRCUIT
1. Check for continuity between the (N7) FTP Sensor Signal circuit and the FTP Sensor Return circuit at the FTP Sensor harness connector.
  Is there continuity between the (N7) FTP Sensor Signal circuit and the FTP Sensor Return circuit?
  
  Yes
  - Repair the short between the (N7) FTP Sensor Signal circuit and the FTP Sensor Return circuit.
  - Perform the POWERTRAIN VERIFICATION TEST. Refer to POWERTRAIN VERIFICATION TEST .
  No
  - Go To 6
POWERTRAIN CONTROL MODULE (PCM)
1. Using the wiring diagram/schematic as a guide, inspect the wiring and connectors for the Powertrain Control Module (PCM).
2. Look for any chafed, pierced, pinched or partially broken wires.
3. Look for broken, bent, pushed out or corroded terminals.
4. Perform any Service Bulletins that may apply.
  Were there any problems found?
  
  Yes
  - Repair as necessary.
  - Perform the POWERTRAIN VERIFICATION TEST. Refer to POWERTRAIN VERIFICATION TEST .
  No
  - Replace and program the Powertrain Control Module in accordance with the Service Information. Refer to MODULE, POWERTRAIN CONTROL, REMOVAL .
  - Perform the POWERTRAIN VERIFICATION TEST. Refer to POWERTRAIN VERIFICATION TEST .