Diagnostic Procedure
- Perform ON-BOARD DIAGNOSTIC II SYSTEM CHECK under SELF-DIAGNOSTIC SYSTEM. After performing OBD-II system check, go to next step.
- Start engine and run until normal operating temperature is achieved (minimum 176°F 80°C). Turn ignition on, engine off. Using scan tool, observe Acceleration Position Sensor (APS) angle while slowly opening throttle. At idle position, APS1 value should equal 9-17 percent, APS2 and 3 should equal 83-91 percent. Slowly press accelerator pedal to wide open throttle. APS angle values should increase steadily and smoothly. At wide open throttle APS 1 value should be 83-91 percent, APS2 value should be 9-17 percent, APS3 value should be 30-38 percent. If APS values are as specified, go to next step. If APS values are not as specified, go to step 4.
- Using scan tool, retrieve DTCs. If DTC P1125 was reset, go to step 8. If DTC P1125 was not reset, check for intermittent problem. See DIAGNOSTIC AIDS .
- Disconnect APS 10-pin harness connector. APS is located on accelerator pedal. Using DVOM, measure voltage between specified APS harness connector terminals. See CHECKING ACCELERATOR POSITION SENSOR CIRCUITS table. See Fig 1. Voltage reading should be 5 volts. If voltage is as specified, go to next step. If voltage is not as specified, go to step 6.CHECKING ACCELERATOR POSITION SENSOR CIRCUITS
Accelerator Position Sensor No. Accelerator Position Sensor Harness Connector Terminals (Wire Color) 1 No. 10 (Black) & 4 (Red) 2 No. 8 (Green) & 3 (Blue) 3 No. 1 (Green wire) & 7 (Orange/Blue) - Check for short to voltage in AP1, AP2 and AP3 sensor signal circuit between sensor and PCM. Check for high resistance in AP1, AP2 and AP3 sensor ground circuit between sensor and PCM. Check for poor, loose or corroded connection in AP1, AP2 and AP3 sensor ground circuit between sensor and PCM. See WIRING DIAGRAMS article. If problem is found, repair as necessary. After repair is complete, see VERIFYING VEHICLE REPAIR under SELF-DIAGNOSTIC SYSTEM. If no problem is found, go to next step.
- Check for poor, loose or corroded connection in AP1, AP2 and AP3 sensor 5-volt reference and signal circuits between sensor and PCM. Check for high resistance in AP1, AP2 and AP3 sensor 5-volt reference and signal circuits between sensor and PCM. If problem is found, repair as necessary. After repair is complete, see VERIFYING VEHICLE REPAIR under SELF-DIAGNOSTIC SYSTEM. If no problem is found, go to next step.
- Replace suspect APS. See REMOVAL, OVERHAUL & INSTALLATION article. After repair is complete, see VERIFYING VEHICLE REPAIR under SELF-DIAGNOSTIC SYSTEM.
- Replace and reprogram PCM. See POWERTRAIN CONTROL MODULE REPLACEMENT under POWERTRAIN CONTROL MODULE. Use scan tool to clear DTC and verify repair