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:
If there are any 5-Volt Supply DTCs present, perform the diagnostics for those DTCs before continuing with this one.
1. Start the engine and allow it to reach normal operating temperature.
2. With the scan tool, read DTCs and record on the repair order.
  Is the DTC active or pending?
  
  Yes
  - Go To 2
  No
  - Perform the INTERMITTENT CONDITION diagnostic procedure. Refer to INTERMITTENT CONDITION .
CHECK THE (K860) 5-VOLT SUPPLY CIRCUIT FOR A SHORT TO VOLTAGE
1. Turn the ignition off.
2. Disconnect the Crankcase Pressure Sensor harness connector.
3. Turn the ignition on.
4. Measure the voltage on the (K860) 5-Volt Supply circuit at the Crankcase Pressure Sensor harness connector.
  Is the voltage above 5.2 volts?
  
  Yes
  - Repair the (K860) Crankcase Pressure Sensor Signal circuit for a short to voltage.
  - Perform the POWERTRAIN VERIFICATION TEST. Refer to POWERTRAIN VERIFICATION TEST, 16V Turbo .
  No
  - Go To 3
CHECK THE (K926) CRANKCASE PRESSURE SENSOR SIGNAL CIRCUIT FOR A SHORT TO VOLTAGE
1. Measure the voltage on the (K926) Crankcase Pressure Sensor Signal circuit at the Crankcase Pressure Sensor harness connector.
  Is there any voltage present?
  
  Yes
  - Repair the (K926) Crankcase Pressure Sensor Signal circuit for a short to voltage.
  - Perform the POWERTRAIN VERIFICATION TEST. Refer to POWERTRAIN VERIFICATION TEST, 16V Turbo .
  No
  - Go To 4
CHECK THE (K926) CRANKCASE PRESSURE SENSOR SIGNAL CIRCUIT FOR A SHORT TO THE (K860) 5-VOLT SUPPLY CIRCUIT
1. Turn the ignition off.
2. Disconnect the PCM C2 harness connector.
3. Check for continuity between the (K926) Crankcase Pressure Sensor Signal circuit and the (K860) 5-Volt Supply circuit at the Crankcase Pressure Sensor harness connector.
  Is there continuity between the (K926) Crankcase Pressure Sensor Signal circuit and the (K860) 5-Volt Supply circuit?
  
  Yes
  - Repair the short between the (K926) Crankcase Pressure Sensor Signal circuit and the (K860) 5-Volt Supply circuit.
  - Perform the POWERTRAIN VERIFICATION TEST. Refer to POWERTRAIN VERIFICATION TEST, 16V Turbo .
  No
  - Go To 5
CHECK THE (K915) SENSOR GROUND CIRCUIT FOR AN OPEN/HIGH RESISTANCE
1. Measure the resistance of the (K915) Sensor Ground circuit between the Crankcase Pressure Sensor harness connector and the PCM C2 harness connector.
  Is the resistance below 3.0 Ohms?
  
  Yes
  - Go To 6
  No
  - Repair the (K915) Sensor Ground circuit for an open/high resistance.
  - Perform the POWERTRAIN VERIFICATION TEST. Refer to POWERTRAIN VERIFICATION TEST, 16V Turbo .
CRANKCASE PRESSURE SENSOR
1. Reconnect the PCM C2 harness connector.
2. Connect a jumper between the (K926) Crankcase Pressure Sensor Signal circuit and the (K915) Sensor Ground circuit at the Crankcase Pressure Sensor harness connector.
3. Turn the ignition on.
4. With the scan tool, read DTCs.
  NOTE:
  The scan tool should display the P051C-CRANKCASE PRESSURE SENSOR CIRCUIT LOW DTC as active or pending with the jumper in place.
  
  Does the DTC display as described above?
  
  Yes
  - Replace the Crankcase Pressure Sensor in accordance with the Service Information.
  - Perform the POWERTRAIN VERIFICATION TEST. Refer to POWERTRAIN VERIFICATION TEST, 16V Turbo .
  No
  - Go To 7
CHECK RELATED PCM AND COMPONENT CONNECTIONS
1. Perform any Service Bulletins that apply.
2. Disconnect all PCM harness connectors.
3. Disconnect all related in-line harness connections (if equipped).
4. Disconnect the related component harness connectors.
5. Inspect harness connectors, component connectors, and all male and female terminals for the following conditions:
  - Proper connector installation.
  - Damaged connector locks.
  - Corrosion.
  - Other signs of water intrusion.
  - Weather seal damage (if equipped).
  - Bent terminals.
  - Overheating due to a poor connection (terminal may be discolored due to excessive current draw).
  - Terminals that have been pushed back into the connector cavity.
  - Check for spread terminals and verify proper terminal tension.
  Repair any conditions that are found.
6. Reconnect all PCM harness connectors. Be certain that all harness connectors are fully seated and the connector locks are fully engaged.
7. Reconnect all in-line harness connectors (if equipped). Be certain that all connectors are fully seated and the connector locks are fully engaged.
8. Reconnect all related component harness connectors. Be certain that all connectors are fully seated and the connector locks are fully engaged.
9. With the scan tool, erase DTCs.
10. Test drive or operate the vehicle in accordance with the when monitored and set conditions.
11. With the scan tool, read DTCs.
  Did the DTC return?
  
  Yes
  - Replace 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, 16V Turbo .
  No
  - Perform the POWERTRAIN VERIFICATION TEST. Refer to POWERTRAIN VERIFICATION TEST, 16V Turbo .
  - Test complete.