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:
When this DTC is Active the engine speed, torque and vehicle speed are limited to a Limp in mode.

NOTE:
If there are any 5-Volt Reference DTCs present, diagnose and repair those DTCs before continuing with this test procedure.
1. Turn the ignition on.
  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 can result in possible serious or fatal injury.
  
  NOTE:
  If you are viewing data recorder information or Freeze Frame data the APP Sensor No. 2 is pulled low by the PCM as part of its system testing. This test happens every 320 milliseconds and may not show up on the scan tool but may show up on a data recorder or lab scope. It is acceptable to see the voltage close to zero with a normal sensor when using a data recorder/lab scope.
2. With the scan tool, read DTCs and record on the repair order.
  Is the DTC active or pending?
  
  Yes
  - Go To 2
  No
  - Go To 9
CHECK THE (K852) 5-VOLT SUPPLY CIRCUIT 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 between 4.8 and 5.2 volts?
  
  Yes
  - Go To 3
  No
  - Repair the (K852) 5-Volt Supply circuit for an open or short to ground.
  - Perform the POWERTRAIN VERIFICATION TEST. Refer to POWERTRAIN VERIFICATION TEST, 16V Turbo .
CHECK THE (K23) APP SENSOR 1 SIGNAL CIRCUIT FOR AN OPEN/HIGH RESISTANCE
1. Turn the ignition off.
2. Disconnect the PCM C1 harness connector.
3. Measure the resistance of the (K23) APP Sensor 1 Signal circuit between the APP Sensor harness connector and the PCM C1 harness connector.
  Is the resistance below 5.0 Ohms?
  
  Yes
  - Go To 4
  No
  - Repair the (K23) APP Sensor 1 Signal circuit for an open or high resistance.
  - Perform the POWERTRAIN VERIFICATION TEST. Refer to POWERTRAIN VERIFICATION TEST, 16V Turbo .
CHECK THE (K23) APP SENSOR 1 SIGNAL CIRCUIT FOR A SHORT TO GROUND
1. Check for continuity between ground and the (K23) APP Sensor 1 Signal circuit at the APP Sensor harness connector.
  Is there continuity between ground and the (K23) APP Sensor 1 Signal circuit?
  
  Yes
  - Repair the short to ground in the (K23) APP Sensor 1 Signal circuit.
  - Perform the POWERTRAIN VERIFICATION TEST. Refer to POWERTRAIN VERIFICATION TEST, 16V Turbo .
  No
  - Go To 5
CHECK FOR THE (K23) APP SENSOR 1 SIGNAL CIRCUIT SHORTED TO THE (K167) APP SENSOR 1 RETURN CIRCUIT
1. Check for continuity between the APP Sensor 1 Signal circuit and the Sensor 1 Return circuit at the APP Sensor harness connector.
  Is there continuity between the APP Sensor 1 Signal circuit and the Sensor 1 Return circuit?
  
  Yes
  - Repair the short between the (K23) APP Sensor 1 Signal circuit and the (K167) APP Sensor 1 Return circuit.
  - Perform the POWERTRAIN VERIFICATION TEST. Refer to POWERTRAIN VERIFICATION TEST, 16V Turbo .
  No
  - Go To 6
CHECK FOR THE (K23) APP SENSOR 1 SIGNAL CIRCUIT SHORTED TO THE (K400) APP SENSOR 2 RETURN CIRCUIT
1. Check for continuity between the (K23) APP Sensor 1 Signal circuit and the (K400) APP Sensor 2 Return circuit in the APP Sensor harness connector.
  Is there continuity between the (K23) APP Sensor 1 Signal circuit and the (K400) APP Sensor 2 Return circuit?
  
  Yes
  - Repair the short between the (K23) APP Sensor 2 Return circuit and the (K400) APP Sensor 1 Signal circuit.
  - Perform the POWERTRAIN VERIFICATION TEST. Refer to POWERTRAIN VERIFICATION TEST, 16V Turbo .
  No
  - Go To 7
ACCELERATOR PEDAL POSITION SENSOR
1. Reconnect the PCM C1 harness connectors.
2. Turn the ignition on.
3. With the scan tool, monitor the APP Sensor 1 voltage.
4. Connect a jumper between the (K852) 5-Volt Supply circuit and the (K23) APP Sensor 1 Signal circuit at the Sensor harness connector.
  NOTE:
  The sensor voltage should be approximately 5.0 volts (plus or minus.1 volts) with the jumper installed.
  
  Does the scan tool display the voltage as described above?
  
  Yes
  - Verify that there is good pin to terminal contact in the APP Sensor and Powertrain Control Module connectors. If OK, replace the APP Sensor Assembly in accordance with the Service Information. Refer to SENSOR, ACCELERATOR PEDAL POSITION . After installation is complete, use a scan tool and perform the Reset Accelerator Pedal Adaptives to relearn the APP Sensor values.
  - Perform the POWERTRAIN VERIFICATION TEST. Refer to POWERTRAIN VERIFICATION TEST, 16V Turbo .
  No
  - Go To 8
    NOTE:
    Remove the jumper wire before continuing.
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.
APP SENSOR SWEEP
1. Turn the ignition on.
2. With the scan tool, monitor the APP Sensor 1 voltage.
3. Slowly press the Accelerator pedal down.
  Does voltage start at approximately 0.45 volts and go to approximately 4.6 volts with a smooth transition?
  
  Yes
  - Perform the INTERMITTENT CONDITION diagnostic procedure. Refer to INTERMITTENT CONDITION .
  No
  - Replace the APP Sensor Assembly in accordance with the Service Information. Refer to SENSOR, ACCELERATOR PEDAL POSITION . After installation is complete, use a scan tool and perform the Reset Accelerator Pedal Adaptives to relearn the APP Sensor values.
  - Perform the POWERTRAIN VERIFICATION TEST. Refer to POWERTRAIN VERIFICATION TEST, 16V Turbo .