| 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. On models equipped with engine immobilizer, if ECM is replaced, ECM must be programmed with proper ignition key code for engine immobilizer system. For programming procedures, see COMPUTER RELEARN PROCEDURES article in GENERAL INFORMATION, or appropriate ENGINE IMMOBILIZER SYSTEMS article in ACCESSORIES & EQUIPMENT. |
Circuit Description
Crankshaft position sensor is a pick-up coil located on front of engine, near crankshaft pulley and uses a 34-tooth signal plate located on the crankshaft. ECM uses input signals from crankshaft position sensor to determine crankshaft angle and engine speed. DTC P0335 is set when ECM does not receive input signal from crankshaft position sensor when engine is cranking or with engine speed more than 600 RPM. DTC P1335 is set when ECM does not receive input signal from crankshaft position sensor when engine is running. Possible causes are
- Crankshaft position sensor circuit is open or shorted.
- Defective crankshaft 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, crankshaft position sensor operation may be checked by reading crankshaft position sensor waveform pattern with engine idling. This may be done by monitoring the crankshaft position sensor signal which may be referred to as the NE signal. Crankshaft position sensor waveform pattern may be checked by connecting oscilloscope between terminals No. 16 (Red wire) and No. 24 (Pink wire) at ECM electrical connector E5. This is the NE+ and NE- terminals on ECM. ECM is located behind passenger's side kick panel, just below instrument panel. see scheme 2 For ECM electrical connector terminal identification see scheme 4 Crankshaft position sensor waveform pattern should be properly displayed. (Scheme 313)
Scheme 313
Scheme 314
- Disconnect electrical connector for crankshaft position sensor. Crankshaft position sensor is located on front of engine, near crankshaft pulley. (Scheme 314)
- Using ohmmeter, check resistance between electrical terminals on crankshaft position sensor. Resistance should be 985-1600 ohms with sensor temperature of 14-122°F (-10-50°C) and 1265-1890 ohms with sensor temperature of 122-212°F (50-100°C). If resistance is within specification, go to next step. If resistance is not within specification, replace crankshaft position sensor. See CRANKSHAFT POSITION SENSOR under IGNITION SYSTEMS in REMOVAL, OVERHAUL & INSTALLATION - 4-CYLINDER article.
- Check for open and short in wiring harness and electrical connectors between crankshaft position sensor and ECM. See WIRING DIAGRAMS article. ECM is located behind passenger's side kick panel, just below instrument panel. see scheme 2 If wiring harness and electrical connectors are okay, go to next step. If wiring harness or electrical connector is defective, repair as necessary.
- Remove crankshaft position sensor. See CRANKSHAFT POSITION SENSOR under IGNITION SYSTEMS in REMOVAL, OVERHAUL & INSTALLATION - 4-CYLINDER article. Inspect crankshaft position sensor and teeth on signal plate located on the crankshaft for damage. If crankshaft position sensor or signal plate is damaged, replace components as necessary. If crankshaft position sensor and signal plate are okay, replace ECM.