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Home >> Chevrolet >> 2001 >> Venture Base, Van Passenger >> Repair and Diagnosis >> External Pages >> Different car >> Section 180 (Engine Controls - Self-Diagnostics - 2.2L) >> Diagnostic Tests >> DTC P1220: Throttle Position Sensor No. 2 Circuit >> Diagnostic Procedures

Diagnostic Procedures

WARNING: This page is about a different car, the 2003 Saturn Vue. However, it is still accessible from the selected car via links, so may be relevant.
  1. Perform diagnostic system check - engine controls. See DIAGNOSTIC SYSTEM CHECK - ENGINE CONTROLS  under SELF-DIAGNOSTIC SYSTEM. After performing diagnostic system check - engine controls, go to next step.
  2. Turn ignition on, with engine off. Observe the TP sensor voltage with the accelerator pedal in the rest position with a scan tool. Does the scan tool indicate voltage less than 0.27 volt or greater than 4.67 volts? If yes, go to step  4. If no, go to next step.
  3. Observe the Freeze Frame/Failure Records for this DTC. Turn ignition off for 90 seconds. Start engine. Operate the vehicle within the Conditions for Running the DTC. See CONDITIONS FOR RUNNING DTC . You may also operate the vehicle within the conditions that you observed from the Freeze Frame/Failure Records. Does the DTC fail this ignition? If yes, go to next step. If no, problem is intermittent. See INTERMITTENTS in TROUBLE SHOOTING - NO CODES - 2.2L & 3.0L VUE article.
  4. Turn ignition off. Disconnect the throttle body harness connector. Turn ignition on, with engine off. Observe the TP sensor No. 2 voltage parameter with a scan tool. Does the scan tool indicate that the TP sensor No. 2 voltage is greater than 4.8 volts? If yes, go to next step. If no, go to step  12.
  5. Probe the TP sensor signal circuit with a test light connected to ground. Does the test light illuminate? If yes, go to step  12. If no, go to next step.
  6. Observe the TP sensor No. 2 parameter with a test light still connected to the TP sensor signal circuit. Does the scan tool indicate that the voltage is less than 0.25 volt? If yes, go to next step. If no, go to step  11.
  7. Measure the voltage of the TP sensor No. 2 5-volt reference circuit with a DVOM. Does the DVOM indicate that the voltage is greater than 4.8 volts? If yes, go to next step. If no, go to step  10.
  8. Turn ignition off for 90 seconds. Allow the ECM to completely power down. This can be verified by the loss of communication on the scan tool. Measure the resistance from the low reference circuit of the TP sensor to the ECM case with the DVOM. Is the resistance less than 5 ohms? If yes, go to next step. If no, go to step  14.
  9. Test TP sensor low reference circuit for a short to ground. Did you find and correct the condition? If yes, go to step  22. If no, go to step  18.
  10. Does the DVOM indicate that the voltage is less than 5 volts on the TP sensor No. 2 5-volt reference circuit? If yes, go to step  15. If no, go to step  17.
  11. Test TP sensor No. 2 signal circuit for an open or for high resistance. Did you find and correct the condition? If yes, go to step  22. If no, go to step  13.
  12. Test TP sensor No. 2 signal circuit for a short to voltage. Did you find and correct the condition? If yes, go to step  22. If no, go to step  20.
  13. Test TP sensor No. 2 signal circuit for a short to ground. Did you find and correct the condition? If yes, go to step  22. If no, go to step  20.
  14. Test TP sensor No. 2 low reference circuit for an open or for high resistance. Did you find and correct the condition? If yes, go to step  22. If no, go to step  20.
  15. Test TP sensor 2 5-volt reference circuit for an open or for high resistance. Did you find and correct the condition? If yes, go to step  22. If no, go to next step.
  16. Test TP sensor 2 5-volt reference circuit for a short to ground. Did you find and correct the condition? If yes, go to step  22. If no, go to step  20.
  17. Test TP sensor 2 5-volt reference circuit for a short to voltage. Did you find and correct the condition? If yes, go to step  22. If no, go to next step.
  18. Inspect for poor connections at the throttle body harness connector. Did you find and correct the condition? If yes, go to step  22. If no, go to next step.
  19. Replace throttle body assembly. After replacing throttle body, go to step  22.
  20. Inspect for poor connections at the ECM harness connector. Did you find and correct the condition? If yes, go to step  22. If no, go to next step.
  21. Turn ignition off. Replace ECM. Perform ECM relearn procedure. See ELECTRONIC CONTROL MODULE REPROGRAMMING  under PROGRAMMING. After replacing ECM, go to next step.
  22. Using scan tool, clear DTCs. Turn ignition off for 30 seconds. Operate vehicle within the conditions for running the DTC. See CONDITIONS FOR RUNNING DTC . You may also operate vehicle within the conditions observed from the Freeze Frame/Failure Records. Did the DTC fail this ignition? If yes, go to step  2. If no, go to next step.
  23. With a scan tool, observe the stored information, Capture Info. Does the scan tool display any DTCs that you have not diagnosed? If yes, see DIAGNOSTIC TROUBLE CODE DEFINITIONS . If no, system is okay.
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