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. 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 DTC diagnostic procedure. Refer to INTERMITTENT CONDITION .
CHECK THE (K21) IAT SIGNAL CIRCUIT FOR A SHORT TO VOLTAGE
1. Turn the ignition off.
2. Disconnect the MAP Sensor harness connector.
3. Turn the ignition on.
4. Measure the voltage on the (K21) IAT Signal circuit at the MAP Sensor harness connector.
  Is the voltage above 5.2 volts?
  
  Yes
  - Repair the (K21) IAT Signal circuit for a short to voltage.
  - Perform the POWERTRAIN VERIFICATION TEST. Refer to POWERTRAIN VERIFICATION TEST .
  No
  - Go To 3
CHECK THE (K21) IAT 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 (K21) IAT Signal circuit between the MAP Sensor harness connector and the PCM C2 harness connector.
  Is the resistance below 3.0 Ohms?
  
  Yes
  - Go To 4
  No
  - Repair the (K21) IAT Signal circuit for an open or high resistance.
  - Perform the POWERTRAIN VERIFICATION TEST. Refer to POWERTRAIN VERIFICATION TEST .
CHECK THE (K900) SENSOR GROUND CIRCUIT FOR AN OPEN/HIGH RESISTANCE
1. Measure the resistance of the (K900) Sensor Ground circuit between the MAP Sensor harness connector and the PCM C2 harness connector.
  Is the resistance below 3.0 Ohms?
  
  Yes
  - Go To 5
  No
  - Repair the (K900) Sensor Ground circuit for an open or high resistance.
  - Perform the POWERTRAIN VERIFICATION TEST. Refer to POWERTRAIN VERIFICATION TEST .
CHECK THE INTAKE AIR TEMPERATURE SENSOR
1. Reconnect the MAP Sensor harness connector.
2. Connect a jumper between the (K21) IAT Signal circuit and the (K900) Sensor Ground at the MAP Sensor harness connector.
3. Turn the ignition on.
4. With the scan tool, read DTCs and record on the repair order.
  NOTE:
  The P0112-INTAKE AIR TEMPERATURE SENSOR 1 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 MAP Sensor in accordance with the Service Information. Refer to SENSOR, MANIFOLD AIR PRESSURE (MAP), REMOVAL .
  - Perform the POWERTRAIN VERIFICATION TEST. Refer to POWERTRAIN VERIFICATION TEST .
  No
  - Go To 6
POWERTRAIN CONTROL MODULE (PCM)
1. Using the wiring diagram/schematic as a guide, inspect the wiring and connectors between the MAP Sensor 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.
4. Monitor the scan tool data relative to this circuit and wiggle test the wiring and connectors.
5. Look for the data to change or for the DTC to reset during the wiggle test.
6. Perform any Service Bulletins that may apply.
  Were any problems found?
  
  Yes
  - Repair as necessary.
  - Perform the POWERTRAIN VERIFICATION TEST. Refer to POWERTRAIN VERIFICATION TEST .
  No
  - 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 .