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:
Diagnose and repair any system voltage or sensor supply voltage DTCs before continuing with this test.
1. Turn the ignition on.
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 (K852) 5-VOLT SUPPLY CIRCUIT FOR A SHORT TO VOLTAGE
1. Turn the ignition off.
2. Disconnect the APP Sensor harness connector.
3. Turn the ignition on.
4. Measure the voltage on the (K852) 5-Volt Supply circuit at the APP Sensor harness connector.
  Is the voltage above 5.2 volts?
  
  Yes
  - Repair the (K852) 5-Volt Supply circuit for a short to voltage.
  - Perform the POWERTRAIN VERIFICATION TEST. Refer to POWERTRAIN VERIFICATION TEST, 16V Turbo .
  No
  - Go To 3
CHECK THE (K29) APP SENSOR SIGNAL 2 CIRCUIT FOR A SHORT TO BATTERY VOLTAGE
1. Measure the voltage on the (K29) APP Sensor Signal 2 circuit at the APP Sensor harness connector.
  Is the voltage above 5.2 volts?
  
  Yes
  - Repair the (K29) APP Sensor Signal 2 circuit for a short to Battery voltage.
  - Perform the POWERTRAIN VERIFICATION TEST. Refer to POWERTRAIN VERIFICATION TEST, 16V Turbo .
  No
  - Go To 4
CHECK THE (K29) APP SENSOR SIGNAL 2 CIRCUIT FOR A SHORT TO THE (K852) 5-VOLT SUPPLY CIRCUIT
1. Turn the ignition off.
2. Disconnect the PCM C1 harness connector.
3. Check for continuity between the (K29) APP Sensor Signal 2 circuit and the (K852) 5-Volt Supply circuit at the APP Sensor harness connector.
  Is there continuity between the (K29) APP Sensor Signal 2 circuit and the (K852) 5-Volt Supply circuit?
  
  Yes
  - Repair the (K29) APP Sensor Signal 2 circuit for a short to the (K852) 5-Volt Supply circuit.
  - Perform the POWERTRAIN VERIFICATION TEST. Refer to POWERTRAIN VERIFICATION TEST, 16V Turbo .
  No
  - Go To 5
CHECK THE (K29) APP SENSOR SIGNAL 2 CIRCUIT FOR A SHORT TO THE (K854) 5-VOLT SUPPLY CIRCUIT
1. Check for continuity between the (K29) APP Sensor Signal 2 circuit and the (K854) 5-Volt Supply circuit at the APP Sensor harness connector.
  Is there continuity between the (K29) APP Sensor Signal 2 circuit and the (K854) 5-Volt Supply circuit?
  
  Yes
  - Repair the (K29) APP Signal 2 circuit for a short to the (K854) 5-Volt Supply circuit.
  - Perform the POWERTRAIN VERIFICATION TEST. Refer to POWERTRAIN VERIFICATION TEST, 16V Turbo .
  No
  - Go To 6
CHECK THE ACCELERATOR PEDAL POSITION SENSOR
1. Reconnect the PCM C1 harness connector.
2. Connect a jumper between the (K29) APP Sensor Signal 2 circuit and the (K400) APP Sensor Ground circuit at the APP Sensor harness connector.
3. Turn the ignition on.
4. With the scan tool, read DTCs.
  NOTE:
  The P2127-ACCELERATOR PEDAL POSITION SENSOR 2 CIRCUIT LOW DTC should display as active or pending with the jumper in place.
  
  Does the scan tool display as described above?
  
  Yes
  - Replace the Accelerator Pedal Position 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 and program the Powertrain Control Module (PCM) 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.