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.
- Perform ON-BOARD DIAGNOSTIC II SYSTEM CHECK under SELF-DIAGNOSTIC SYSTEM. After performing OBD-II system check, go to next step.
- Perform ELECTRIC THROTTLE CONTROL SYSTEM CHECK under SELF-DIAGNOSTIC SYSTEM. After performing ELECTRIC THROTTLE CONTROL 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 to wide open throttle. APS angle values should increase steadily and smoothly as specified. See CHECKING ACCELERATOR POSITION SENSORS table. If APS values are as specified, check for intermittent problem. See DIAGNOSTIC AIDS . If APS values are not 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 - 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, go to next step. If voltage parameter is not as specified, go to step 6.
- Connect test light between specified APS harness connector terminals. See CHECKING ACCELERATOR POSITION SENSOR CIRCUITS table. See Fig 1. On scan tool, observe APS voltage parameter. Voltage reading should be about 5 volts. If voltage is as specified, go to step 7. If voltage is not as specified, go to step 8.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 (Green/Blue) - Check for short to voltage in APS1, APS2 and APS3 signal circuit between sensor and PCM. Check for high resistance in APS1, APS2 and APS3 sensor ground circuit between sensor and PCM. Check for poor, loose or corroded connection in APS1, APS2 and APS3 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 step 9.
- 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. 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.
- Replace APS. See ENGINE SENSOR & SWITCHES in 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.