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Home >> Chevrolet >> 2001 >> Camaro Base, 2D Convertible, Automatic >> Repair and Diagnosis >> External Pages >> Different car >> Section 7 (Engine Control System Self-Diagnostics - 5.7L) >> Diagnostic Tests >> DTC P1275: Accelerator Pedal Position (App) Sensor No. 1 Circuit ("Y" Body) >> Diagnostic Procedures

Diagnostic Procedures

WARNING: This page is about a different car, the 2000 Pontiac Firebird, 2000 Chevrolet Corvette, and 2000 Chevrolet Camaro. However, it is still accessible from the selected car via links, so may be relevant.
  1. Perform On-Board Diagnostic (OBD) system check. See ON-BOARD DIAGNOSTIC (OBD) SYSTEM CHECK . After performing OBD system check, go to next step.
    NOTE: If DTC P1120 or P1518 is also present, diagnose affected DTC first. See DTC P1120: TP SENSOR NO. 1 CIRCUIT ("Y" BODY)  or DTC P1518: THROTTLE ACTUATOR CONTROL (TAC) MODULE SERIAL DATA CIRCUIT ("Y" BODY) .
  2. Turn ignition on, engine off. Ensure accelerator pedal is not depressed. Using scan tool, select TAC DATA LIST option. Monitor APP sensor No. 1 voltage. If voltage reading is 0.25-2.24 volts, go to next step. If voltage reading is not 0.25-2.24 volts, go to step  6.
  3. Fully depress accelerator pedal. Check voltage reading on scan tool. If voltage reading is 2.24-4.23 volts, go to next step. If voltage reading is not 2.24-4.23 volts, go to step  6.
  4. Turn ignition off for 15 seconds. Turn ignition on, engine off. Using scan tool, select DTC option and FAILED THIS IGNITION option. Move/wiggle harness connectors and related connectors. If this DTC sets, go to step  29. If this DTC does not set, go to next step.
  5. Depress accelerator pedal to Wide Open Throttle (WOT) position then return to closed position. If this DTC sets, go to step  25. If this DTC does not set, problem is intermittent. See DIAGNOSTIC AIDS .
  6. Disconnect APP sensor harness connector. If scan tool reads zero volts, go to next step. If scan tool does not read zero volts, go to step  11.
  7. Using a test light connected to battery voltage, probe APP sensor No. 1 signal circuit. If scan tool reads 5 volts, go to next step. If scan tool does not read 5 volts, go to step  13.
  8. Check voltage between APP sensor No. 1 5-volt reference circuit and battery ground. If voltage reading is 4.6-5.4 volts, go to step  10. If voltage reading is not 4.6-5.4 volts, go to next step.
    NOTE: Disconnecting throttle actuator motor harness connector will set additional DTCs.
  9. Turn ignition off. Disconnect throttle actuator motor connector. Remove air inlet duct from throttle body. Turn ignition on, with engine off. Rotate throttle blade by hand to wide open throttle. Hold throttle blade in this position. Check voltage between APP sensor No. 1 5-volt reference circuit at harness connector and battery ground. If voltage reading is 4.6-5.4 volts, go to step  26. If voltage reading is not 4.6-5.4 volts, go to step  16.
  10. Check resistance between APP sensor No. 1 ground circuit and battery ground. If resistance is 0-5 ohms, go to step  24. If resistance is not 0-5 ohms, go to step  17.
  11. Turn ignition off. Leave APP sensor disconnected. Disconnect TAC module connector containing the APP sensor circuits. Turn ignition on, with engine off. Check voltage between battery ground and APP sensor No. 1 signal circuit in APP sensor harness connector. If voltage reading is zero volts, go to next step. If voltage reading is not zero volts, go to step  18.
  12. Turn ignition off. Disconnect the other TAC module connector. Check continuity between APP sensor No. 1 signal circuit and all other circuits in both TAC module connectors. If continuity exists, go to step  19. If continuity does not exist, go to step  28.
  13. Turn ignition off. Disconnect TAC module connector containing the APP sensor circuits. Check continuity of APP sensor No. 1 signal circuit. If continuity exists, go to next step. If continuity does not exist, go to step  20.
  14. Check continuity between APP sensor No. 1 signal circuit and battery ground. If continuity exists, go to step  21. If continuity does not exist, go to next step.
  15. Turn ignition off. Disconnect the other TAC harness connector. Check continuity between APP sensor No. 1 signal circuit and all other circuits in both TAC module connectors. If continuity exists, go to step  19. If continuity does not exist, go to step  27.
  16. Turn ignition off. Leave APP sensor harness connector disconnected. Disconnect TAC module harness connector containing APP sensor circuit. Check continuity of APP sensor No. 1 5-volt reference circuit. If continuity exists, go to step  27. If continuity does not exist, go to step  22.
  17. Turn ignition off. Leave APP sensor harness connector disconnected. Disconnect TAC module harness connector containing APP sensor circuit. Check continuity of APP sensor No. 1 ground circuit. If continuity exists, go to step  27. If continuity does not exist, go to step  23.
  18. Repair signal circuit for short to voltage. After repairs, go to step  30.
  19. Repair short between APP sensor signal circuit and TAC circuit that had continuity. After repairs, go to step  30.
  20. Repair open or high resistance in signal circuit. After repairs, go to step  30.
  21. Repair short to ground in signal circuit. After repairs, go to step  30.
  22. Repair open or high resistance in 5-volt reference circuit. After repairs, go to step  30.
  23. Repair open or high resistance in ground circuit. After repairs, go to step  30.
  24. Check for poor connection or terminal tension at APP sensor harness connector. Repair as necessary. After repairs, go to step  30. If connection or terminal tension is okay, go to next step.
  25. Replace accelerator pedal assembly. After replacing pedal assembly, go to step  30.
  26. If DTC P1120 was set when performing step  9, diagnose using DTC P1120 test. If DTC P1120 was not set, go to next step.
  27. Check for poor connection or terminal tension at TAC module harness connector. Repair as necessary. After repairs, go to step  30. If connector or terminal tension is okay, go to next step.
  28. Replace TAC module. After replacing module, go to next step.
  29. Repair harness connectors as necessary. After repairs, go to next step.
  30. Using scan tool, select DTC, CLEAR INFO. Start and warm engine to normal operating temperature. Select DTC, SPECIFIC, then enter this DTC. Operate vehicle within the conditions for setting this DTC. If scan tool indicates that this test ran and passed, go to next step. If scan tool does not indicate that this test ran and passed, repeat step  2.
  31. Using scan tool, select CAPTURE INFO, REVIEW INFO. If any undiagnosed DTC(s) are displayed, go to applicable DTC test.
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