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Diagnostic Procedure

WARNING: This page is about a different car, the 2002 Isuzu Rodeo Sport, 2002 Isuzu Rodeo, 2002 Isuzu Axiom, and 2002 Honda Passport. However, it is still accessible from the selected car via links, so may be relevant.
  1. Perform ON-BOARD DIAGNOSTIC II SYSTEM CHECK  under SELF-DIAGNOSTIC SYSTEM. After performing OBD-II system check, go to next step.
  2. Perform ELECTRIC THROTTLE CONTROL SYSTEM CHECK  under SELF-DIAGNOSTIC SYSTEM. After performing electronic throttle control system check, go to next step.
  3. Using scan tool, observe APS angle parameter while slowly opening throttle valve. APS3 angle reading should change steadily and evenly as specified. See CHECKING ACCELERATOR POSITION SENSORS table. If APS operate as specified, check for intermittent problem. See DIAGNOSTIC AIDS . If APS does not operate as specified, go to next step.
    CHECKING ACCELERATOR POSITION SENSORS

    Accelerator Position Sensor Specification (%)
    Accelerator Position Sensor No. 1
    Closed Throttle 13
    Wide Open Throttle 85-89
    Accelerator Position Sensor No. 2
    Closed Throttle 85-89
    Wide Open Throttle 11-15
    Accelerator Position Sensor No. 3
    Closed Throttle 85-89
    Wide Open Throttle 32-36
  4. Turn ignition off. Disconnect APS 10-pin harness connector. APS is located on accelerator pedal. On scan tool, observe APS voltage parameter. If voltage parameter is about zero volts, leave harness connector disconnected and go to next step. If voltage parameter is not as specified, go to step  6.
  5. Connect test light between specified APS harness connector terminals. See CHECKING ACCELERATOR POSITION SENSOR CIRCUITS table. See Figure. On scan tool, observe APS voltage parameters. Each APS voltage parameter should be about 5 volts. If voltage parameters are as specified, go to step  8. If voltage parameter are not as specified, go to step  7.
    CHECKING ACCELERATOR POSITION SENSOR CIRCUITS

    Accelerator Position Sensor No. Measure Between Terminals (Wire Color)
    1 No. 10 (Black) & 5 (White)
    2 No. 8 (Green) & 9 (Yellow)
    3 No. 1 (Orange) & 6 (Blue/Green)
  6. Check for short to voltage in APS1, 2 and 3 signal circuits. Check for high resistance in APS1, 2 and 3 ground circuit between PCM and APS. Check for poor connections in APS1, 2 and 3 ground circuit. 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 step  9.
  7. Check for poor connections in APS1, 2 and 3 signal or 5-volt supply circuit. Check for high resistance in APS1, 2 and 3 signal or 5-volt supply circuit between PCM and APS. 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.
  8. Replace APS. See ENGINE SENSORS & SWITCHES in REMOVAL, OVERHAUL & INSTALLATION article. After repair is complete, see VERIFYING VEHICLE REPAIR  under SELF-DIAGNOSTIC SYSTEM.
  9. Replace and reprogram PCM. See POWERTRAIN CONTROL MODULE REPLACEMENT  under POWERTRAIN CONTROL MODULE. Use scan tool to clear DTC and verify repair.
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