| 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. 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 signal 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 with engine cranking or with engine speed of 600 RPM or more. DTC P1335 is set when ECM does not receive input signal from crankshaft position sensor with engine speed of 1000 RPM or more. Possible causes are
- Crankshaft position sensor circuit is open or shorted.
- Defective crankshaft position sensor.
- Defective signal plate.
- Defective ECM.
Diagnostic Aids
DTC P0335 uses two-trip detection logic. 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. 22 (Red wire) and No. 23 (Green wire) at ECM electrical connector E8. This is the NE- and NE+ terminals on ECM. ECM is located behind glove box and heater duct. see scheme 2 For ECM electrical connector terminal identification see scheme 4 Crankshaft position sensor waveform pattern should be properly displayed. (Scheme 59)
Scheme 59
Scheme 60
- Crankshaft position sensor should be checked. Remove lower engine cover for access to crankshaft position sensor. Crankshaft position sensor is located at front of crankshaft, near crankshaft pulley. (Scheme 60) Disconnect electrical connector for crankshaft position sensor.
- Manufacturer lists inspection procedure with crankshaft position sensor removed before checking the resistance. Remove bolt and crankshaft position sensor. Using ohmmeter, check resistance between electrical terminals on crankshaft position sensor. Resistance should be 1630-2740 ohms with sensor temperature of 14-122°F (-10-50°C) and 2065-3225 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. Reinstall crankshaft position sensor. Tighten crankshaft position sensor bolt to 58 INCH lbs. (6.6 N.m). Reinstall electrical connector and lower engine cover.
- Check for open and short in wiring harness and electrical connectors between crankshaft position sensor and ECM. See «WIRING DIAGRAMS»(ref-133228) article. ECM is located behind glove box and heater duct. 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.
- 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 and reinstall crankshaft position sensor. Tighten crankshaft position sensor bolt to 58 INCH lbs. (6.6 N.m). Reinstall electrical connector and lower engine cover. If crankshaft position sensor and signal plate are okay, replace ECM. Reinstall crankshaft position sensor. Tighten crankshaft position sensor bolt to 58 INCH lbs. (6.6 N.m). Reinstall electrical connector and lower engine cover.