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. Start the engine.
2. Allow the engine to reach normal operating temperature.
  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.
3. 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 (K42) KNOCK SENSOR 1 SIGNAL CIRCUIT FOR A SHORT TO VOLTAGE
1. Turn the ignition off.
2. Disconnect the Knock Sensor harness connector.
3. Turn the ignition on.
4. Measure the voltage on the (K42) Knock Sensor 1 Signal circuit in the Knock Sensor harness connector.
  Is the voltage above 5.2 volts?
  
  Yes
  - Repair the (K42) Knock Sensor 1 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 (K42) KNOCK SENSOR 1 SIGNAL CIRCUIT FOR AN OPEN/HIGH RESISTANCE
1. Turn the ignition off.
2. Disconnect the PCM C2 harness connector.
3. Measure the resistance of the (K42) Knock Sensor 1 Signal circuit from the Knock Sensor harness connector to the PCM C2 harness connector.
  Is the resistance below 3.0 Ohms?
  
  Yes
  - Go To 4
  No
  - Repair the (K42) Knock Sensor 1 Signal circuit for an open or high resistance.
  - Perform the POWERTRAIN VERIFICATION TEST. Refer to POWERTRAIN VERIFICATION TEST, 16V Turbo .
CHECK THE (K942) KNOCK SENSOR 1 RETURN CIRCUIT FOR AN OPEN/HIGH RESISTANCE
1. Measure the resistance of the (K942) Knock Sensor 1 Return circuit from the Knock Sensor harness connector to the PCM C2 harness connector.
  Is the resistance below 3.0 Ohms?
  
  Yes
  - Go To 5
  No
  - Repair the (K942) Knock Sensor 1 Return circuit for an open or high resistance.
  - Perform the POWERTRAIN VERIFICATION TEST. Refer to POWERTRAIN VERIFICATION TEST, 16V Turbo .
CHECK FOR THE (K42) KNOCK SENSOR 1 SIGNAL CIRCUIT SHORTED TO THE (K942) KNOCK SENSOR 1 RETURN CIRCUIT
1. Check for continuity between the (K42) Knock Sensor 1 Signal circuit and the (K942) Knock Sensor 1 Return circuit in the Knock Sensor harness connector.
  Is there continuity between the (K42) Knock Sensor Signal circuit and the (K942) Knock Sensor Return circuit?
  
  Yes
  - Repair the short between the (K42) Knock Sensor 1 Signal circuit and the (K942) Knock Sensor 1 Return circuit.
  - Perform the POWERTRAIN VERIFICATION TEST. Refer to POWERTRAIN VERIFICATION TEST, 16V Turbo .
  No
  - Go To 6
CHECK THE (K42) KNOCK SENSOR 1 SIGNAL CIRCUIT FOR A SHORT TO GROUND
1. Check for continuity between ground and the (K42) Knock Sensor 1 Signal circuit at the Knock Sensor harness connector.
  Is there continuity between ground and the (K42) Knock Sensor Signal circuit?
  
  Yes
  - Repair the (K42) Knock Sensor 1 Signal circuit for a short to ground.
  - Perform the POWERTRAIN VERIFICATION TEST. Refer to POWERTRAIN VERIFICATION TEST, 16V Turbo .
  No
  - Go To 7
KNOCK SENSOR
1. Turn the ignition off.
2. Verify that there is good pin to terminal contact at the Knock Sensor and the Powertrain Control Module harness connector.
3. If no problems were found in the connectors, replace the Knock Sensor 1. Refer to SENSOR, KNOCK, REMOVAL .
4. Reconnect the PCM C2 harness connector.
5. Turn the ignition on.
6. With the scan tool, erase DTCs.
7. Start the engine and allow it to reach normal operating temperature.
  WARNING:
  When the engine is operating, do not stand in direct line with the fan. Do not put your hands near the pulleys, belts or fan. Do not wear loose clothing. Failure to follow these instructions may result in possible serious or fatal injury.
  
  NOTE:
  It may be necessary to test drive the vehicle within the DTC monitoring conditions in order for this DTC to reset.
8. With the scan tool, read DTCs.
  Is the DTC active or pending?
  
  Yes
  - Go To 8
  No
  - Test complete.
  - Perform the POWERTRAIN VERIFICATION TEST. Refer to POWERTRAIN VERIFICATION TEST, 16V Turbo .
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.