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1998 Toyota 4Runner Repair Question


Topics covered: Sensor, Wiring, Camshaft.
Mileage: 275,000 miles.

Asked on February 17, 2013

Toyota 4Runner Sensor Problem

Just changed timing belt and cam sensor cleared computer codes po340 keeps returning and car has no power could ecm be the problem
Avatar Asked by dbl054

Answer

Replied on February 17, 2013

DTC P0340: CAMSHAFT POSITION (CMP) SENSOR CIRCUIT

CAUTION: If ECM replacement is instructed in following testing, always ensure ECM connectors and ground circuit are okay. If either are suspect, repair and repeat
testing to confirm ECM malfunction.

Circuit Description

The CMP sensor is a pick up coil mounted on left side of cylinder head. A 1 tooth signal plate is mounted on intake camshaft. DTC is set when either no cranking or engine running signal is received by ECM from
sensor. Possible causes are:

? Open or short in CMP sensor circuit.
? CMP sensor.
? Starter.
? ECM.

Diagnosis & Repair

1. Disconnect CMP sensor connector. Using ohmmeter, measure resistance between CMP sensor connector terminals. Resistance should be 835 1400 ohms (cold sensor) or 1060 1645 ohms (hot sensor).
2. Replace CMP sensor as necessary. If CMP sensor is okay, check for open or short circuit in wiring harness between ECM and CMP sensor. See appropriate wiring diagram in WIRING DIAGRAMS article.
Repair wiring as necessary.
3. If wiring harness is okay, remove and inspect CMP sensor. Also inspect signal plate. Replace CMP sensor and/or signal plate as necessary. If both components are okay, replace ECM.

Tiny Answered by hmac300 (expert)
17,848 answers provided