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.

VEHICLE HISTORY AND SERVICE BULLETIN INVESTIGATION
1. Turn the ignition on.
2. With the scan tool, read DTCs. Record the Freeze Frame data if any DTCs are present.
3. Whether or not any DTCs are Active you will want to check the following items which may assist in repairing the customer's complaint successfully.
  - Check the vehicle's repair history.
  - If the vehicle has a repair history that pertains to the customer's current complaint, review the repair.
  - Inspect the vehicle for any aftermarket accessories that may have been installed incorrectly.
  - Check for any service bulletin(s) related to the customer's complaint or DTCs.
  - If a service bulletin applies, follow the instructions per the service bulletin.
  Choose the following scenario that applies.
  
  The service bulletin repaired the customer's complaint.
  - Testing complete.
  A DTC is present, no service bulletins apply or the service bulletin didn't repair the customer's complaint.
  - Go To 2
CHECK FOR AN ACTIVE DTC
NOTE:
If there are any Fuel Tank Pressure Sensor DTCs present, diagnose and repair those DTCs before continuing with this test procedure.
1. Start the engine.
2. Test drive the vehicle in accordance with the set conditions.
3. With the scan tool, read DTCs.
  NOTE:
  If any other DTC sets, active or pending, perform the diagnostic procedure for that DTC before proceeding with this test.
  
  Is the DTC active or pending?
  
  Yes
  - Go To 3
  No
  - Perform the INTERMITTENT CONDITION diagnostic procedure. Refer to INTERMITTENT CONDITION .
CHECK THE (K859) FTP SENSOR SUPPLY CIRCUIT FOR VOLTAGE
1. Turn the ignition off.
2. Disconnect the FTP Sensor harness connector.
3. Turn the ignition on.
4. Measure the voltage between ground and the (K859) FTP Sensor Supply circuit at the FTP Sensor harness connector.
  Is the voltage between 4.8 and 5.2 volts?
  
  Yes
  - Go To 4
  No
  - Repair the (K859) FTP Sensor Supply circuit for an open circuit or short to ground.
  - Perform the POWERTRAIN VERIFICATION TEST. Refer to POWERTRAIN VERIFICATION TEST, 16V Turbo .
CHECK FOR HIGH RESISTANCE IN THE (N7) FTP SENSOR SIGNAL CIRCUIT
1. Turn the ignition off.
2. Disconnect the PCM C1 harness connector.
3. Measure the resistance of the (N7) FTP Sensor Signal circuit between the FTP Sensor harness connector and the PCM C1 harness connector.
  Is the resistance below 3.0 Ohms?
  
  Yes
  - Go To 5
  No
  - Repair the (N7) FTP Sensor Signal circuit for an open or high resistance.
  - Perform the POWERTRAIN VERIFICATION TEST. Refer to POWERTRAIN VERIFICATION TEST, 16V Turbo .
CHECK FOR HIGH RESISTANCE IN THE (K917) FTP SENSOR RETURN CIRCUIT
1. Measure the resistance of the (K917) FTP Sensor Return circuit between the FTP Sensor harness connector and the PCM C1 harness connector.
  Is the resistance below 3.0 Ohms?
  
  Yes
  - Go To 6
  No
  - Repair the (K917) FTP Sensor Return circuit for an open or high resistance.
  - Perform the POWERTRAIN VERIFICATION TEST. Refer to POWERTRAIN VERIFICATION TEST, 16V Turbo .
VISUALLY INSPECT THE TURBO RELATED EVAPORATIVE SYSTEM COMPONENTS
1. Turn the ignition off.
2. Perform a visual and physical inspection of the Turbo related Evaporative Emission system components. Check for the following conditions:
  - Verify the flow direction arrow on the tee on the boost vacuum purge harness is pointing from the Charge Air Cooler (CAC) (high pressure) to the air induction (low pressure)
  - Check for the Purge Solenoid vacuum hose to be pinched/bent/blocked between the intake manifold to purge solenoid
  - Check for the Evap purge hose to be pinched/bent/blocked between Purge Solenoid, Fuel tank and Evap Purge Canister
  - Check for blockage/obstruction between CAC port and the ejector tee
  Were any of the above conditions found?
  
  Yes
  - Repair as necessary.
  - Perform the POWERTRAIN VERIFICATION TEST. Refer to POWERTRAIN VERIFICATION TEST, 16V Turbo .
  No
  - Go To 7
VISUALLY INSPECT THE REMAINDER OF THE SYSTEM
1. Turn the ignition off.
2. Perform a visual and physical inspection of the entire Evaporative Emission system. Check for the following conditions:
  - Improper installation of the Fuel Fill Cap
  - Holes or cracks
  - Loose seal points
  - Evidence of damaged components
  - Incorrect routing of hoses and tubes
  - Loose or missing Fuel Filler Cap
  - Damaged Locking tabs on Fuel Cap and/or fill tube
  - Damaged seal points on Fuel Cap and/or fill tube
  - Fuel cap gasket seal
  Were any of the above conditions found?
  
  Yes
  - Repair as necessary.
  - Perform the POWERTRAIN VERIFICATION TEST. Refer to POWERTRAIN VERIFICATION TEST, 16V Turbo .
  No
  - Go To 8
EVAP PURGE SOLENOID
NOTE:
To continue testing you will need the Evaporative Emission Leak Detector (EELD) (special tool #8404C, Kit, EELD And Accessory).

WARNING:
Keep lit cigarettes, sparks, flames, and other ignition sources away from the test area to prevent the ignition of explosive gases, Keep the test area well ventilated.
1. Connect the red power lead of the EELD to the battery positive terminal and the black ground lead to battery negative terminal.
2. Disconnect the vacuum hoses at the Evap Purge Solenoid.
3. Connect the SMOKE supply tip (black hose) to the "CAN" port on the Evap Purge Solenoid.
4. Set the smoke/air control switch to SMOKE.
5. While still holding the remote smoke/air start button, check to see if smoke is exiting the purge valve. This indicates that there is a leak internal to the purge valve.
  NOTE:
  This is an optional method of checking the purge valve for leaks if the EELD is unavailable.
6. Using a hand vacuum pump, apply 10 in Hg to the "CAN" side of the Purge Solenoid.
7. Observe the vacuum gauge for at least 15 seconds.
  NOTE:
  The solenoid should hold vacuum for a minimum of 15 seconds.
  
  Is smoke visible from the Purge Solenoid or does it NOT hold a vacuum?
  
  Yes
  - Verify that there is good pin to terminal contact at the Purge Solenoid and the Powertrain Control Module connectors. Replace the Purge Solenoid if no problems were found in the connectors.
  - Perform the POWERTRAIN VERIFICATION TEST. Refer to POWERTRAIN VERIFICATION TEST, 16V Turbo .
  No
  - Go To 9
POWERTRAIN CONTROL MODULE (PCM)
1. Using the wiring diagram/schematic as a guide, inspect the wiring and connectors between the Purge Solenoid and the Powertrain Control Module (PCM).
  - Look for any chafed, pierced, pinched or partially broken wires.
  - Look for broken, bent, pushed out or corroded terminals.
  - 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 .