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Home >> Alfa Romeo >> 2019 >> Giulia Base, AWD >> Repair and Diagnosis >> Engine Performance >> System >> 2.0L - DTCS P0112-00 To P024B-00 >> DTC Troubleshooting >> P0122-00-Throttle/Pedal Position Sensor/Switch "A" Circuit Low >> Diagnostic Test

Diagnostic Test

  1. CHECK FOR AN ACTIVE DTC 
    NOTE:

    Diagnose and repair any system voltage or 5-Volt Reference DTCs before continuing with this test.

    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 

  2. CHECK THE (K22) TPS SIGNAL CIRCUIT FOR A SHORT TO GROUND 
    1. Turn the ignition off.
    2. Disconnect the Throttle Body harness connector.
    3. Disconnect the PCM C2 harness connector.
    4. Check for continuity between ground and the (K22) TPS Signal circuit at the TPS harness connector.

      Is there continuity between ground and the (K22) TPS Signal circuit?

      Yes 

      • Repair the (K22) TPS Signal circuit for a short to ground.
      • Perform the POWERTRAIN VERIFICATION TEST. Refer to POWERTRAIN VERIFICATION TEST .

      No 

      • Go To  3
  3. CHECK THE (K22) TPS SIGNAL CIRCUIT FOR A SHORT TO THE (K922) TPS RETURN CIRCUIT 
    1. Check for continuity between the (K22) TPS Signal circuit and the (K922) TPS Return circuit at the Throttle Body harness connector.

      Is there continuity between the (K22) TPS Signal circuit and the (K922) TPS Return circuit?

      Yes 

      • Repair the short between the (K22) TPS Signal circuit and the (K922) TPS Return circuit.
      • Perform the POWERTRAIN VERIFICATION TEST. Refer to POWERTRAIN VERIFICATION TEST .

      No 

      • Go To  4
  4. CHECK THE (K22) TPS SIGNAL CIRCUIT FOR A SHORT TO THE (K448) ETC MOTOR (-) CIRCUIT 
    1. Check for continuity between the (K22) TPS Signal circuit and the (K448) ETC Motor (-) circuit at the Throttle Body harness connector.

      Is there continuity between the (K22) TPS Signal circuit and the (K448) ETC Motor (-) circuit?

      Yes 

      • Repair the short between the (K22) TPS Signal circuit and the (K448) ETC Motor (-) circuit.
      • Perform the POWERTRAIN VERIFICATION TEST. Refer to POWERTRAIN VERIFICATION TEST .

      No 

      • Go To  5
  5. CHECK THE (K22) TPS SIGNAL CIRCUIT FOR A SHORT TO THE (K447) ETC MOTOR (+) CIRCUIT 
    1. Check for continuity between the (K22) TPS Signal circuit and the (K447) ETC Motor (+) circuit at the Throttle Body harness connector.

      Is there continuity between the (K22) TPS Signal circuit and the (K447) ETC Motor (+) circuit?

      Yes 

      • Repair the short between the (K22) TPS Signal circuit and the (K447) ETC Motor (+) circuit.
      • Perform the POWERTRAIN VERIFICATION TEST. Refer to POWERTRAIN VERIFICATION TEST .

      No 

      • Go To  6
  6. CHECK THE (K22) TPS SIGNAL CIRCUIT FOR AN OPEN/HIGH RESISTANCE 
    1. Measure the resistance of the (K22) TPS Signal circuit between the Throttle Body harness connector and the PCM C2 harness connector.

      Is the resistance below 3.0 Ohms?

      Yes 

      • Go To  7

      No 

      • Repair the (K22) TPS Signal circuit for an open or high resistance.
      • Perform the POWERTRAIN VERIFICATION TEST. Refer to POWERTRAIN VERIFICATION TEST .
  7. THROTTLE POSITION SENSOR 
    1. Reconnect the PCM C2 harness connector.
    2. Connect a jumper between the (F851) 5-Volt Supply circuit and the (K22) TPS Signal circuit at the Throttle Body harness connector.
    3. Turn the ignition on.
    4. With the scan tool, read DTCs.
      NOTE:

      The DTC P0123-00-THROTTLE/PEDAL POSITION SENSOR/SWITCH "A" CIRCUIT HIGH should be active or pending with the jumper in place.

      Does the scan tool display 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 in accordance with the Service Information. Refer to THROTTLE BODY, REMOVAL AND INSTALLATION . Disconnect the Battery when replacing the Throttle Body Assembly. After installation is complete, using a scan tool, perform the ETC RELEARN procedure.
      • Perform the POWERTRAIN VERIFICATION TEST. Refer to POWERTRAIN VERIFICATION TEST .

      No 

      • Go To  8
  8. 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 C2 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 

      No 

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