LEMON Manuals: Even more car manuals for everyone
Home >> Chevrolet >> 2001 >> Camaro Base, 2D Convertible, Automatic >> Repair and Diagnosis >> External Pages >> Different car >> Section 43 (Engine Control System Self-Diagnostics - 3.8L) >> Diagnostic Tests >> DTC P1515: Commanded & Actual Throttle Position Mismatch >> Diagnostic Procedures

Diagnostic Procedures

WARNING: This page is about a different car, the 2002 Pontiac Firebird and 2002 Chevrolet Camaro. 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, see DIAGNOSTIC SYSTEM CHECK - ENGINE CONTROLS  under SELF-DIAGNOSTIC SYSTEM.
    2. NOTE: If you came from one of the following DTC tables continue with this procedure and go to next step.
  2. Is DTC P1120, P1220 or P1221 set? If yes, diagnose those DTCs first. See DIAGNOSTIC TROUBLE CODE DEFINITIONS . If no, go to next step.
  3. Turn OFF the ignition for 15 seconds. Turn ON the ignition, with the engine OFF. With a scan tool, observe the TP sensor 1 and 2 angle parameter. Slowly depress the accelerator pedal to Wide Open Throttle (WOT) and then slowly return the pedal to closed throttle. Does the TP sensor 1 and 2 angle increase to near 100 percent as the pedal is depressed and decrease as the pedal is released? If yes, see DIAGNOSTIC AIDS . If no, go to next step.
  4. Turn OFF the ignition. Disconnect the TAC. Turn ON the ignition, with the engine OFF. Measure the voltage across the throttle actuator circuits, motor high and motor low, using a DMM. Does the voltage measure 7.5-8.5 V? If yes, go to step  15. If no, go to next step.
  5. Measure the voltage on each throttle actuator circuit, motor high and motor low, using a DMM that is connected to a good ground. Is any voltage present? If yes, go to step  9. If no, go to next step.
  6. Test for an open in each throttle actuator circuit, motor high and motor low. Did you find a condition? If yes, go to step  10. If no, go to next step.
  7. Test for a short to ground on each throttle actuator circuit, motor high and motor low. Did you find a condition? If yes, go to step  11. If no, go to next step.
  8. Test for continuity between each throttle actuator circuit, motor high and motor low, and all other circuits in the TAC module connector. Is continuity indicated? If yes, go to step  12. If no, go to step  13.
  9. Repair the short to voltage on the affected throttle actuator circuit. After repairs, go to step  17.
  10. Repair the open or high resistance on the affected throttle actuator circuit. After repairs, go to step  17.
  11. Repair the short to ground on the affected throttle actuator circuit. After repairs, go to step  17.
  12. Repair the circuits that are shorted together. After repairs, go to step  17.
  13. Inspect for poor connections at the TAC module. Did you find and correct the condition? If yes, go to step  17. If no, go to next step.
  14. Replace the TAC module. See appropriate REMOVAL, OVERHAUL & INSTALLATION article. After repairs, go to step  17.
  15. Inspect for poor connections at the TAC. If yes, go to step  17. If no, go to next step.
  16. Replace the throttle body of the TAC assembly. See appropriate REMOVAL, OVERHAUL & INSTALLATION article. After repairs, go to next step.
  17. Clear the DTCs with a scan tool. Turn OFF the ignition. Start the engine. Operate the vehicle within the Conditions for Running DTC. Does the DTC run and pass? If yes, go to next step. If no, go to step  2.
  18. Observe the stored information, Capture Info with a scan tool. Does the scan tool display any DTCs that you have not diagnosed? If yes, see DIAGNOSTIC TROUBLE CODE DEFINITIONS . If no, system is okay.
scientia non olet · About LEMON Manuals