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:
If P2101 is also set, make sure that the blade moves freely and does not hang up near Wide Open Throttle before trying to repair P0123.
1. Start the engine and allow it to idle.
  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 may result in possible serious or fatal injury.
2. With the scan tool, read DTCs.
  Is the DTC active?
  
  Yes
  - Go To 3
  No
  - Go To 2
THROTTLE FOLLOWER TEST
1. Turn the ignition on.
2. With the scan tool, perform the ETC Throttle Follower Test and monitor the TPS 1 or TPS 2 voltage.
3. Slowly press the accelerator pedal down.
4. The voltage for TPS 1 should start at approximately 0.7 volts and increase to approximately 4.3 volts.
  Is the TPS 1 voltage within the range of the listed specification?
  
  Yes
  - Perform the INTERMITTENT CONDITION diagnostic procedure. Refer to INTERMITTENT CONDITION .
  No
  - Go To 3
CHECK THE (K22) TPS 1 SIGNAL CIRCUIT FOR A SHORT TO VOLTAGE
1. Turn the ignition off.
2. Disconnect the Throttle Body harness connector.
3. Turn the ignition on.
4. Measure the voltage between ground and the (K22) TPS 1 Signal circuit at the Throttle Body harness connector.
  Is the voltage reading above 5.2 volts?
  
  Yes
  - Repair the (K22) TPS 1 Signal circuit for a short to voltage.
  - Perform the POWERTRAIN VERIFICATION TEST. Refer to POWERTRAIN VERIFICATION TEST, 16V Turbo .
  No
  - Go To 4
CHECK THE (K22) TPS 1 SIGNAL CIRCUIT FOR AN OPEN/HIGH RESISTANCE
1. Turn the ignition off.
2. Disconnect the PCM C2 harness connector.
  CAUTION:
  Do not probe the PCM harness connectors. Probing the PCM harness connectors will damage the PCM terminals resulting in poor terminal to pin connection. Install the GPEC Diagnostic Adaptor to perform the diagnosis.
3. Connect the (special tool #10436, Adapter, GPEC Diagnostic).
4. Measure the resistance of the (K22) TPS 1 Signal circuit from the Throttle Body harness connector to the GPEC Adaptor.
  Is the resistance below 3.0 Ohms?
  
  Yes
  - Go To 5
  No
  - Repair the (K22) TPS 1 Signal circuit for an open or high resistance.
  - Perform the POWERTRAIN VERIFICATION TEST. Refer to POWERTRAIN VERIFICATION TEST, 16V Turbo .
CHECK THE (K922) TPS RETURN CIRCUIT FOR AN OPEN/HIGH RESISTANCE
1. Measure the resistance of the (K922) TPS Return circuit from the Throttle Body harness connector to the GPEC Adaptor.
  Is the resistance below 3.0 Ohms?
  
  Yes
  - Go To 6
  No
  - Repair the (K922) TPS Return circuit for an open or high resistance.
  - Perform the POWERTRAIN VERIFICATION TEST. Refer to POWERTRAIN VERIFICATION TEST, 16V Turbo .
CHECK FOR THE (K22) TPS 1 SIGNAL CIRCUIT SHORTED TO THE (F855) 5-VOLT SUPPLY CIRCUIT
1. Check for continuity between the (K22) TPS 1 Signal circuit and the (F855) 5-Volt Supply circuit in the Throttle Body harness connector.
  Is there continuity between the (K22) TPS 1 Signal circuit and the (F855) 5-Volt Supply circuit?
  
  No
  - Go To 7
  Yes
  - Repair the short between the (F855) 5-Volt Supply circuit and the (K22) TPS 1 Signal circuit.
  - Perform the POWERTRAIN VERIFICATION TEST. Refer to POWERTRAIN VERIFICATION TEST, 16V Turbo .
CHECK THE (K22) TPS 1 SIGNAL CIRCUIT FOR A SHORT TO THE ETC MOTOR (-) CIRCUIT
1. Check for continuity between the (K22) TPS 1 Signal circuit and the ETC Motor (-) circuit at the Throttle Body harness connector.
  Is there continuity between the (K22) TPS 1 Signal circuit and the ETC Motor (-) circuit?
  
  Yes
  - Repair the short between the (K22) TPS 1 Signal circuit and the ETC Motor (-) circuit.
  - Perform the POWERTRAIN VERIFICATION TEST. Refer to POWERTRAIN VERIFICATION TEST, 16V Turbo .
  No
  - Go To 8
CHECK THE (K22) TPS 1 SIGNAL CIRCUIT FOR A SHORT TO THE ETC MOTOR (+) CIRCUIT
1. Check for continuity between the (K22) TPS 1 Signal circuit and the ETC Motor (+) circuit at the Throttle Body harness connector.
  Is there continuity between the (K22) TPS 1 Signal circuit and the ETC Motor (+) circuit?
  
  Yes
  - Repair the short between the (K22) TPS 1 Signal circuit and the ETC Motor (+) circuit.
  - Perform the POWERTRAIN VERIFICATION TEST. Refer to POWERTRAIN VERIFICATION TEST, 16V Turbo .
  No
  - Go To 9
THROTTLE POSITION SENSOR
1. Turn the ignition off.
2. Reconnect the PCM C2 harness connector.
3. Turn the ignition on, engine not running.
4. Connect a jumper between the (K22) TPS 1 Signal circuit and the (K922) TPS Return circuit at the Throttle Body harness connector.
5. With the scan tool, read DTCs.
  NOTE:
  The scan tool should display a P0122-THROTTLE POSITION SENSOR 1 CIRCUIT LOW DTC as active or pending with the jumper in place.
  
  Does the scan tool display the DTC as described above?
  
  Yes
  - Verify that there is good pin to terminal contact in the Throttle Body and Powertrain Control Module connectors. If no problems are found, replace the Throttle Body Assembly. Refer to THROTTLE BODY . Disconnect the Battery when replacing the Throttle Body Assembly. After installation is complete, using a scan tool select the ETC RELEARN function. .
  - Perform the POWERTRAIN VERIFICATION TEST. Refer to POWERTRAIN VERIFICATION TEST, 16V Turbo .
  No
  - Go To 10
POWERTRAIN CONTROL MODULE (PCM)
1. Using the wiring diagram/schematic as a guide, inspect the wiring and connectors between the 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 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 (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 .