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
NOTE:
This DTC sets to indicate a general O2 Sensor system circuit or component failure. The PCM runs secondary tests to pinpoint which circuit has the failure. It is important to diagnose any correlating DTCs relating to this fault first. If there are no other DTCs present, the most likely cause is related to an intermittent circuit connection or component failure.
1. Turn the ignition on.
2. With the scan tool, record then erase DTCs.
3. Start the engine and road test until it reaches normal operating temperature.
4. With the scan tool, read the active, pending or stored DTCs.
  Are there any active, pending or stored DTCs at this time?
  
  Yes
  - Go To 2
  No
  - Perform the INTERMITTENT CONDITION diagnostic procedure. Refer to INTERMITTENT CONDITION .
CORRELATING DTCS
1. With the scan tool, read the pending, active or stored DTCs.
  Are there any correlating active, pending or stored circuit low DTCs at this time?
  
  Yes
  - Perform the diagnostics for the correlating DTC before continuing with this test procedure.
  No
  - Go To 3
CHECK THE O2 SENSOR CIRCUITS 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:
  - (K41) O2 Sensor 1/1 Signal circuit at the O2 Sensor 1/1 harness connector.
  - (K902) O2 Sensor 1/1 Return circuit at the O2 Sensor 1/1 harness connector.
  - (K89) O2 Sensor 1/1 Current Pump Control circuit at the O2 Sensor 1/1 harness connector.
  - (K103) O2 Sensor 1/1 Pump Cell Current Trim at the O2 Sensor 1/1 harness connector.
  Is the continuity between ground and any of the above circuits?
  
  Yes
  - Repair the circuit that showed continuity for a short to ground.
  - Perform the POWERTRAIN VERIFICATION TEST. Refer to POWERTRAIN VERIFICATION TEST .
  No
  - Go To 4
O2 SENSOR
1. Reconnect the PCM C1 harness connector.
2. Replace the O2 Sensor accordance with the Service Information and reconnect the harness connector. Refer to SENSOR, OXYGEN, REMOVAL .
3. Turn the ignition on.
4. With the scan tool, erase DTCs.
5. Start the engine and allow it to idle long enough for the O2 Sensor to enter closed loop operation.
6. With the scan tool, read DTCs.
  Did the DTC return?
  
  Yes
  - Go To 5
  No
  - Repair is complete.
  - Perform the POWERTRAIN VERIFICATION TEST. Refer to POWERTRAIN VERIFICATION TEST .
POWERTRAIN CONTROL MODULE (PCM)
1. Using the wiring diagram/schematic as a guide, inspect the wiring and connectors between the O2 Sensor and 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. Verify that there is good pin to terminal contact in the O2 Sensor and Powertrain Control Module harness connectors.
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 .
  - Perform the POWERTRAIN VERIFICATION TEST. Refer to POWERTRAIN VERIFICATION TEST .