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:
The most likely cause of this DTC is a plugged intake air system or dirty Throttle Body. Check for any Service Bulletins that may apply.

NOTE:
Diagnose any 5-Volt Reference, TPS, Fuel System Lean or Rich, or MAP Sensor DTCs before continuing.
1. Start the engine and allow it to idle.
2. With the scan tool, read DTCs.
  Is the DTC active or pending?
  
  Yes
  - Go To 2
  No
  - Perform the INTERMITTENT CONDITION diagnostic procedure. Refer to INTERMITTENT CONDITION .
CHECK THE INTAKE SYSTEM
1. Turn the ignition off.
2. Inspect the Air Filter and intake inlet for debris such as ice, snow, water or mud that may be causing a restriction.
3. Check the Throttle Body for blade and opening for excessive build up.
  Were any vacuum leaks found?
  
  Yes
  - Perform the appropriate repair.
  - Perform the POWERTRAIN VERIFICATION TEST. Refer to POWERTRAIN VERIFICATION TEST, 16V Turbo .
  No
  - Go To 3
CHECK THE MAP SENSOR OPERATION
1. Start the engine.
2. With the scan tool, monitor MAP Sensor voltage.
3. Snap the throttle to wide open and back to idle.
  Does the MAP Sensor voltage vary from below 2.0 volts at idle to above 3.5 volts at wide open throttle?
  
  Yes
  - Go To 5
  No
  - Go To 4
CHECK THE MAP SENSOR CIRCUITS
1. Start the engine.
2. Disconnect the MAP Sensor harness connector.
3. Disconnect the PCM C2 harness connector.
4. Measure the resistance of all three MAP Sensor circuits between the MAP Sensor harness connector and the PCM C2 harness connector.
  Is the resistance below 5.0 Ohms for all three circuits?
  
  Yes
  - Replace the MAP Sensor in accordance with the Service Information.
  - Perform the POWERTRAIN VERIFICATION TEST. Refer to POWERTRAIN VERIFICATION TEST, 16V Turbo .
  No
  - Repair the excessive resistance in the circuit that measured above 5.0 Ohms.
  - Perform the POWERTRAIN VERIFICATION TEST. Refer to POWERTRAIN VERIFICATION TEST, 16V Turbo .
THROTTLE FOLLOWER TEST
1. Turn the engine off. Turn the ignition on, engine not running.
2. With a scan tool, perform the ETC Throttle Follower Test and monitor the TPS 1 and TPS 2 voltage.
3. Slowly press the throttle pedal down.
4. The voltage for TPS 1 should start at approximately 0.7 volts and increase to approximately 4.3 volts.
5. The voltage for TPS 2 should start at approximately 4.3 volts and decrease to approximately 0.7 volts.
  Is the voltage within the range of the listed specification for the appropriate Sensor?
  
  Yes
  - Go To 7
  No
  - Go To 6
CHECK THE THROTTLE POSITION SENSORS CIRCUITS
1. Turn the ignition off.
2. Disconnect the Throttle Body harness connector.
3. Disconnect the PCM C2 harness connector.
4. Measure the resistance of TPS 1 and TPS 2 Sensor circuits between the Throttle Body harness connector and the PCM C2 harness connector.
  Is the resistance below 5.0 Ohms for all circuits?
  
  Yes
  - Verify that there is good pin to terminal contact in the Throttle Body and Powertrain Control Module connectors. If OK, disconnect the Battery when replacing the Throttle Body Assembly. Replace the Throttle Body Assembly. Refer to THROTTLE BODY, REMOVAL . After installation is complete, use a scan tool and the Throttle Body Self Learning procedure.
  - Perform the POWERTRAIN VERIFICATION TEST. Refer to POWERTRAIN VERIFICATION TEST, 16V Turbo .
  No
  - Repair the excessive resistance in the circuit that measured above 5.0 Ohms.
  - Perform the POWERTRAIN VERIFICATION TEST. Refer to POWERTRAIN VERIFICATION TEST, 16V Turbo .
POWERTRAIN CONTROL MODULE (PCM)
1. Using the wiring diagram/schematic as a guide, inspect the wiring and connectors between the MAP Sensor, Throttle Body 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 MAP Sensor, Throttle Body and Powertrain Control Module 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, 16V Turbo .
  No
  - Replace and program 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 .