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Home >> Chevrolet >> 2002 >> Blazer 4D Utility, 4WD, Part Time >> Repair and Diagnosis >> External Pages >> Different car >> Section 83 (Engine Controls Self-Diagnostics - 2.2L) >> Diagnostic Tests >> DTC P0105: Map/TP Sensor Circuit - Insufficient Activity >> Diagnostic Procedures

Diagnostic Procedures

WARNING: This page is about a different car, the 2002 GMC Sonoma and 2002 Chevrolet S10 Pickup. 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, go to next step.
  2. Install a scan tool. Turn ignition on, with engine off. Observe the TP sensor voltage on the scan tool. Does the scan tool display a TP voltage less than 0.90 volt when the throttle is fully closed? If yes, go to next step. If no, go to step  4.
  3. Select the TP angle parameter on the scan tool. Monitor the scan tool while slowly depressing the accelerator pedal to the floor, then slowly release the pedal. Repeat the procedure several times. Does the TP angle value increase steadily when the accelerator pedal is depressed to more than 98 percent and decrease steadily, returning to less than 1 percent when the pedal is released? If yes, go to step  5. If no, go to step  17.
  4. Check throttle body for binding or damaged linkage. Did you find and correct the condition? If yes, go to step  34. If no, go to step  17.
  5. Observe the Manifold Absolute Pressure (MAP) sensor pressure with a scan tool. Compare this value to a value observed from a known-good vehicle. Is the difference between the MAP values less than 3 kPa? If yes, go to next step. If no, go to step  9.
  6. Start engine. Using scan tool, observe MAP sensor value. Does the MAP sensor value change while starting the engine? If yes, go to next step. If no, go to step  8.
  7. With engine running, snap throttle while observing MAP sensor display on scan tool. Does the MAP sensor value change rapidly when the throttle position changes? If yes, see DIAGNOSTIC AIDS . If no, go to next step.
  8. Turn ignition off. Remove vacuum source from MAP sensor (sensor is located near throttle body, on intake manifold). Check port for vacuum restrictions or leaks. Did you find and correct the condition? If yes, go to step  34. If no, go to next step.
  9. Turn ignition off. Disconnect MAP sensor harness connector. Turn ignition on. Observe MAP sensor voltage on scan tool. Does the scan tool indicate that the voltage is about zero volts? If yes, go to next step. If no, go to step  12.
  10. Connect a test light to a good ground. Probe the 5-volt reference circuit of the MAP sensor with the test light. Does the test light illuminate? If yes, go to next step. If no, go to step  14.
  11. Connect a 3-amp fused jumper to the MAP sensor 5-volt reference circuit. Connect the other end of the 3-amp fused jumper to the MAP sensor signal circuit. Does the scan tool indicate that the voltage is about 5 volts If yes, go to step  13. If no, go to step  15.
  12. Test the MAP sensor signal circuit for a short to voltage. Did you find and correct the condition? If yes, go to step  34. If no, go to step  30.
  13. Connect a test light to B+. Probe the MAP sensor low reference circuit with the test light. Does the test light illuminate? If yes, go to step  28. If no, go to step  16.
  14. Test the 5-volt reference circuit of the MAP sensor for high resistance. Did you find and correct the condition? If yes, go to step  34. If no, go to step  30.
  15. Test the signal circuit of the MAP sensor for high resistance. Did you find and correct the condition? If yes, go to step  34. If no, go to step  30.
  16. Test the MAP sensor low reference circuit for high resistance. Did you find and correct the condition? If yes, go to step  34. If no, go to step  30.
  17. Turn ignition off. Disconnect the TP sensor electrical connector. Turn ON the ignition. Observe the TP sensor voltage on the scan tool. Does the scan tool indicate that the voltage is about 0 volts If yes, go to next step. If no, go to step  21.
  18. Connect a test light to a good ground. Probe the 5-volt reference circuit of the TP sensor with the test light. Does the test light illuminate? If yes, go to next step. If no, go to step  23.
  19. Measure the voltage from the TP sensor 5-volt reference circuit to a good ground. Does the voltage measure more than 5.2 volts If yes, go to step  24. If no, go to next step.
  20. Connect a 3-amp fused jumper to the TP sensor 5-volt reference circuit. Connect the other end of the 3-amp fused jumper to the TP sensor signal circuit. Does the scan tool indicate that the voltage is about 5 volts If yes, go to step  22. If no, go to step  25.
  21. Test the TP sensor signal circuit for a short to voltage. Did you find and correct the condition? If yes, go to step  34. If no, go to step  30.
  22. Connect a test light to B+. Probe the TP sensor low reference circuit at the TP sensor electrical connector with the test light. Does the test light illuminate? If yes, go to step  29. If no, go to step  26.
  23. Test the 5-volt reference circuit of the TP sensor for high resistance. Did you find and correct the condition? If yes, go to step  34. If no, go to step  30.
  24. 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  34. If no, go to step  27.
  25. Test the TP sensor signal circuit for high resistance. Did you find and correct the condition? If yes, go to step  34. If no, go to step  30.
  26. Test the TP sensor low reference circuit for high resistance. Did you find and correct the condition? If yes, go to step  34. If no, go to step  30.
  27. Test the 5-volt reference circuit of the following sensors for a short to voltage: A/C high side pressure sensor or Fuel Tank Pressure (FTP) sensor. Did you find and correct the condition? If yes, go to step  34. If no, go to step  30.
  28. Inspect for poor connections at the MAP sensor. Did you find and correct the condition? If yes, go to step  34. If no, go to step  31.
  29. Inspect for poor connections at the TP sensor electrical connector. Did you find and correct the condition? If yes, go to step  34. If no, go to step  32.
  30. Check for poor connections at PCM harness connector. Did you find and correct the condition? If yes, go to step  34. If no, go to step  33.
  31. Replace MAP sensor. After replacing sensor, go to step  34.
  32. Replace TP sensor. After replacing sensor, go to step  34.
  33. Replace PCM. See appropriate REMOVAL, OVERHAUL & INSTALLATION article. Perform PCM relearn procedure. See POWERTRAIN CONTROL MODULE  under PROGRAMMING. After replacing PCM, go to next step.
  34. Use the scan tool in order to perform the Fuel Trim Reset procedure. Did you complete the procedure? If yes, go to next step.
  35. Clear the DTCs with a scan tool. Turn ignition off for 30 seconds. Start engine. Operate the vehicle within the Conditions for Running this DTC. See CONDITIONS FOR RUNNING DTC . Does the scan tool indicate that this diagnostic ran and passed? If yes, go to next step. If no, go to step  2.
  36. 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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