Code 8: TDC Sensor

NOTE: For wiring diagrams, see WIRING DIAGRAMS article. For vacuum diagrams, see VACUUM DIAGRAMS article.

Turn ignition off. Disconnect alternator sense fuse in under-hood relay box for 10 seconds to reset ECU. Start engine and observe CHECK ENGINE and LED lights. If lights are off, problem is intermittent. Check for poor or loose connections at distributor connector, White/Blue and Orange/Blue wire terminals in connectors No. C305 and C102 at right shock tower. Test drive vehicle and check again.
If CHECK ENGINE light is on and LED indicates Code 8, turn engine off. Disconnect 2-wire sensor connector at distributor. Measure resistance between Orange/Blue and White/Blue wire terminals. If reading is not 500-1000 ohms, replace TDC sensor. If reading is within specification, proceed to next step.
Check continuity between ground and Orange/Blue wire terminal. Check continuity between ground and White/Blue wire terminal. If continuity exists, sensor is shorted to ground. Replace TDC sensor. If no continuity exists, proceed to next step.
Reconnect sensor connector. Attach ECU test harness to wire harness side only. Check resistance between connector C3 and C4 terminals. See Figure . Resistance should be 500-1000 ohms. If resistance is not okay, repair open in Orange/Blue or White/Blue wire.
If resistance is okay, check continuity between terminal C3 and ground. If continuity does not exist, substitute a known good ECU and retest. If condition goes away, replace original ECU. If continuity is present, repair open in Orange/Blue wire between ECU terminal C3 and TDC sensor.