| WARNING | Read service precautions before proceeding with service procedure. See SERVICE PRECAUTIONS . |
| CAUTION | If Engine Control Module (ECM) replacement is instructed in following test, always ensure ECM electrical connectors and ground circuits are okay. If either are defective, repair and repeat testing to confirm ECM malfunction. |
Circuit Description
Camshaft position sensor is a pick-up coil located on end of cylinder head at flywheel end of engine and uses a signal plate on outer circumference of intake camshaft. ECM uses input signals from camshaft position sensor to determine the standard crankshaft angle. DTC is set when ECM does not receive input signal from camshaft position sensor with engine cranking or with engine speed more than 600 RPM. Possible causes are
- Camshaft position sensor circuit is open or shorted.
- Defective camshaft position sensor.
- Defective signal plate.
- Defective ECM.
Diagnostic Aids
Using Toyota hand-held tester or scan tool, read FREEZE FRAME data. Freeze frame data records engine conditions when malfunction is detected.
If oscilloscope is available, camshaft position sensor operation may be checked by reading camshaft position sensor waveform pattern with engine idling. This may be done by monitoring the camshaft position sensor signal which may be referred to as the G2 signal. Camshaft position sensor waveform pattern may be checked by connecting oscilloscope between terminals No. 10 (Red wire) at ECM electrical connector E7 and No. 24 (Green wire) at ECM electrical connector E8. This is the G2 and NE- terminals on ECM. ECM is located behind the glove box. (Схема №3) For ECM electrical connector terminal identification (Схема №7) Camshaft position sensor waveform pattern should be properly displayed. (Схема №16)