Circuit Description
WARNING: This page is about a different car, the 2002 Lexus RX 300. However, it is still accessible from the selected car via links, so may be relevant.
ECM uses signals provided by crankshaft and camshaft position sensors. If engine speed rate has changed enough to equal a preset number, a misfire is detected and MIL is illuminated. If misfire rate is high enough, and driving conditions will cause catalytic converter damage or overheating, MIL blinks when a misfire is occurring. DTC is set during any particular 200 revolutions of engine, misfiring is detected which can cause catalytic converter overheating and/or damage or during any particular 1000 revolutions of engine, misfiring is detected which can cause a deterioration in emission levels. Possible causes are:
- Faulty ignition system.
- Faulty injector(s).
- Incorrect fuel pressure.
- Low engine compression.
- Incorrect valve clearance.
- Incorrect valve timing.
- Faulty Mass Airflow (MAF) sensor.
- Faulty Engine Coolant Temperature (ECT) sensor.
- Open or short in secondary ignition wire.
- Loose connector.
- Faulty ECM.