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 DTCs and record on the repair order.
2. Clear the PCM DTCs.
3. Turn the ignition off for at least one minute.
4. Turn the ignition on.
5. Start the engine.
  NOTE:
  It may be necessary to test drive the vehicle under various load conditions.
  
  Is the DTC active or pending?
  
  Yes
  - Go To 2
  No
  - Check for any Service Bulletins that may apply and verify the PCM is at the latest calibration available. If OK, remove the Camshaft Position Sensor and inspect for any physical damage to the sensor and the cylinder head, repair as necessary. If no problems were found with CMP Sensor and no updates are available for the PCM and the DTC is intermittent it is possible the CMP Sensor gap to the Camshaft Target Wheel is too large or the CMP Signal circuit is picking up interference from another source. Repair as necessary.
CHECK FOR TIMING BELT AND SPROCKET MISALIGNMENT
1. Turn the ignition off.
2. Verify the engine timing is correct in accordance with the Service Information. Refer to VALVE TIMING .
  Are the Camshaft and Crankshaft alignment marks properly lined up as shown in the service procedure?
  
  Yes
  - Go To 3
  No
  - Reassemble the timing belt and sprockets correctly.
  - Perform the POWERTRAIN VERIFICATION TEST. Refer to POWERTRAIN VERIFICATION TEST .
CHECK THE CRANKSHAFT TARGET WHEEL
NOTE:
There are 58 teeth on the Crankshaft Target Wheel. One of the gaps between the 58 teeth is 3 times as wide as the others.
1. Remove the CKP Sensor.
2. Visually inspect the sensor mounting location for damage, foreign material.
3. Rotate the engine and if inspect the target wheel for any defects or signs of damage.
  Were any defects noticed on the CKP Sensor or Target Wheel?
  
  Yes
  - Repair or replace the component as needed in accordance with the Service Information.
  - Perform the POWERTRAIN VERIFICATION TEST. Refer to POWERTRAIN VERIFICATION TEST .
  No
  - Go To 4
CHECK THE CAMSHAFT POSITION SENSOR TARGET WHEEL
1. Remove the CMP Sensor.
2. Visually inspect the sensor mounting location for damage, foreign material.
3. Inspect the CMP target wheel.
  Were any defects noticed on the CMP Sensor or Target Wheel?
  
  Yes
  - Replace the CMP target wheel in accordance with the Service Information.
  - Perform the POWERTRAIN VERIFICATION TEST. Refer to POWERTRAIN VERIFICATION TEST .
  No
  - If the target wheel is disoriented on the camshaft. Replace the camshaft in accordance with the Service Information.
  - Perform the POWERTRAIN VERIFICATION TEST. Refer to POWERTRAIN VERIFICATION TEST .