Diagnosis & Repair
WARNING: This page is about a different car, the 2000 Toyota Land Cruiser. However, it is still accessible from the selected car via links, so may be relevant.
- Turn ignition off. Access ECM behind glove box. Connect an oscilloscope by backprobing between terminal No. 17 (Brown wire) at ECM harness connector E6 and terminal No. 8 (Red wire; circuit M+) or No. 7 (White wire; circuit M-) at ECM harness connector E5. Start engine and allow to idle. Observe waveform. See Fig 1 and Fig 2 . If waveform is okay, replace ECM. If waveform is not okay, go to next step.
- Disconnect throttle control motor Gray, 4-pin harness connector. Measure resistance between terminals No. 1 (White wire) and No. 2 (Red wire) at throttle control motor (component side). Resistance should be .3-100.0 ohms at 68°F (20°C). If resistance is as specified, go to next step. If resistance is not as specified, replace throttle control motor.
- Check for open or short in wiring between throttle control motor and ECM. See WIRING DIAGRAMS article. If problem exists, repair wiring as necessary. If problem does not exist, replace ECM.