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.

ACTIVE DIAGNOSTIC TROUBLE CODE (DTC)
NOTE:
Check the vehicle repair history. If the O2 Sensor 1/2 has been replaced make sure that the O2 sensor was properly installed and meets OEM specification.

NOTE:
Check for contaminants that may have damaged the O2 Sensor: contaminated fuel, unapproved silicone, oil and coolant.
1. Start the engine.
2. Allow the engine to reach normal operating temperature.
3. With the scan tool, read DTCs.
  NOTE:
  It may be necessary to drive the vehicle to meet the conditions to set this DTC, try to repeat the conditions in which the fault originally set by reviewing the Freeze Frame data.
  
  Is the DTC Active or Pending at this time?
  
  Yes
  - Go To 2
  No
  - Perform the INTERMITTENT CONDITION diagnostic procedure. Refer to INTERMITTENT CONDITION .
CHECK THE EXHAUST SYSTEM FOR LEAKS
1. Perform the CHECKING THE EXHAUST SYSTEM FOR LEAKS test procedure. Refer to CHECKING THE EXHAUST SYSTEM FOR LEAKS .
  Were any exhaust leaks found?
  
  Yes
  - Repair or replace the leaking exhaust parts as necessary.
  - Perform the POWERTRAIN VERIFICATION TEST. Refer to POWERTRAIN VERIFICATION TEST .
  No
  - Go To 3
CHECK THE FUEL DELIVERY SYSTEM
1. Perform the CHECKING THE FUEL DELIVERY SYSTEM diagnostic procedure. Refer to CHECKING THE FUEL DELIVERY SYSTEM (HARD START) .
  Were any problems found with the fuel system?
  
  Yes
  - Perform the appropriate repair.
  - Perform the POWERTRAIN VERIFICATION TEST. Refer to POWERTRAIN VERIFICATION TEST .
  No
  - Go To 4
CHECK THE OXYGEN SENSOR OPERATION
1. Perform the CHECKING THE OXYGEN SENSOR OPERATION diagnostic procedure. Refer to DIAGNOSIS AND TESTING .
  Were any problems found?
  
  Yes
  - Repair as necessary in accordance with the Service Information.
  - Perform the POWERTRAIN VERIFICATION TEST. Refer to POWERTRAIN VERIFICATION TEST .
  No
  - Go To 5
ENGINE MECHANICAL
1. Turn the ignition off.
2. Check for any of the following conditions/mechanical problems.
  - AIR INDUCTION SYSTEM - must be free from leaks
  - ENGINE VACUUM - must be at least 13 inches in neutral
  - ENGINE VALVE TIMING - must be within specifications
  - ENGINE COMPRESSION - must be within specifications
  - ENGINE EXHAUST SYSTEM - must be free of any restrictions or leaks
  - ENGINE PCV SYSTEM - must flow freely
  - TORQUE CONVERTER STALL SPEED - must be within specifications
  - POWER BRAKE BOOSTER - no internal vacuum leaks
  - FUEL - must be free of contamination
  - FUEL INJECTOR - plugged or restricted injector; control wire not connected to correct injector
  Are there any engine mechanical problems?
  
  Yes
  - Repair as necessary.
  - 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 relative to the components tested in this procedure.
2. Monitor the scan tool data relative to the components tested in this procedure and wiggle test the wiring and connectors.
3. Look for any chafed, pierced, pinched or partially broken wires.
4. Look for broken, bent, pushed out or corroded terminals.
5. Perform any Technical Service Bulletins that may apply.
  Were any problems found?
  
  Yes
  - Repair as necessary.
  - Perform the POWERTRAIN VERIFICATION TEST. Refer to POWERTRAIN VERIFICATION TEST .
  No
  - Replace and program the PCM in accordance with the Service Information. Refer to MODULE, POWERTRAIN CONTROL, REMOVAL .
  - Perform the POWERTRAIN VERIFICATION TEST. Refer to POWERTRAIN VERIFICATION TEST .