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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. Did you perform the Diagnostic System Check - Engine Controls? If yes, go to next step. If no, go to DIAGNOSTIC SYSTEM CHECK - ENGINE CONTROLS .
  2. Is DTC P0223 also set? If yes, go to DTC P0223: TP SENSOR NO. 2 CIRCUIT - HIGH VOLTAGE . If no, go to next step.
  3. Is DTC P0221 also set? If yes, go to step  8. If no, go to next step.
  4. Turn ignition off. Turn ignition on, with engine off. Observe the TP sensor 1 voltage with a scan tool. Slowly depress the accelerator pedal to Wide-Open Throttle (WOT), then slowly return the pedal to closed throttle. Does the TP sensor 1 voltage increase as the pedal is depressed and decrease as the pedal is released? If yes, problem is intermittent. Refer to INTERMITTENTS in TROUBLE SHOOTING - NO CODES - 2.2L & 3.0L VUE article. If no, go to next step.
  5. Turn ignition off. Disconnect the throttle body harness connector. Turn ignition on, with engine off. Observe the TP sensor 1 parameter with a scan tool. Is the TP sensor 1 voltage more than 4.9 volts? If yes, go to next step. If no, go to step  12.
  6. Probe the signal circuit of the TP sensor 1 with a test light that is connected to a good ground. Does the test light illuminate? If yes, go to step  13. If no, go to next step.
  7. Probe the signal circuit of the TP sensor 1 with a test light that is connected to a good ground. Observe the TP sensor 1 voltage with a scan tool. Is the TP sensor 1 voltage at zero volts? If yes, go to step  17. If no, go to step  14.
  8. Measure the voltage from the 5-volt reference of the TP sensor to a good ground with the DVOM. Is the voltage within 4.8-5.2 volts? If yes, go to next step. If no, go to step  15.
  9. Probe the 5-volt reference circuit of the TP sensor with a test light that is connected to a good ground. Does the test light illuminate? If yes, go to next step. If no, go to step  15.
  10. Turn ignition off. 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 1 to a good ground with the DVOM. Is the resistance less than 5 ohms? If yes, go to next step. If no, go to step  19.
  11. Idle the engine. Observe the MAF sensor g/s with a scan tool. Increase the engine speed slowly to 3000 RPM, then back to idle. Does the MAF sensor g/s change smoothly and gradually through 7-30 g/s? If yes, go to step  20. If no, go to DTC P0101: MASS AIRFLOW SYSTEM PERFORMANCE .
  12. Test the signal circuit of the TP sensor 1 for a short to ground. Did you find and correct the condition? If yes, go to step  22. If no, go to step  20.
  13. Test the signal circuit of the TP sensor 1 for a short to voltage. Did you find and correct the condition? If yes, go to step  22. If no, go to step  20.
  14. Test the 5-volt reference circuit of the TP sensor 1 for a short to ground, high resistance or an open circuit. Repair as necessary. Did you find and correct the condition? If yes, go to step  22. If no, go to step  20.
  15. Test the signal circuit of the TP sensor 1 for a short to ground, short to low reference circuit, high resistance, or an open circuit. Repair as necessary. Did you find and correct the condition? If yes, go to step  22. If no, go to next step.
  16. Test the 5-volt reference circuit of the TP sensor for a short to voltage. Did you find and correct the condition? If yes, go to step  22. If no, go to step  20.
  17. Test for an intermittent and for a poor connection at the TP sensor. Did you find and correct the condition? If yes, go to step  22. If no, go to next step.
  18. Replace throttle body assembly. After replacing throttle body assembly, go to step  22.
  19. Repair the open or high resistance in the low reference circuit. After repairs, go to step  22.
  20. Test for an intermittent and for a poor connection at the ECM. Did you find and correct the condition? If yes, go to step  22. If no, go to next step.
  21. Replace ECM. Perform ECM relearn procedures. See ENGINE CONTROL MODULE  under PROGRAMMING. After replacing ECM, go to step 22
  22. Clear the DTCs with a scan tool. Turn ignition off for 30 seconds. Start engine. Operate 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. Did the DTC fail this ignition? If yes, go to step  2. If no, go to next step.
  23. Observe the Capture Info with a scan tool. Are there any DTCs that have not been diagnosed? If yes, diagnose affected DTC(s). See DIAGNOSTIC TROUBLE CODE DEFINITIONS . If no DTCs are displayed, system is okay.
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