Page 318 - Foton Workshop Manual - Tunland (AT)

04-172 DIAGNOSTICS - ENGINE CONTROL SYSTEM

P234，P238，P239，P689，P731，P2321-CRANKSHAFT

POSITION SENSOR FAULT
P234-ENGINE CRANKSHAFT SPEED / POSITION - DATA IS VALID

BUT ABOVE NORMAL OPERATING RANGE - HIGHEST SEVERITY

04 LEVEL
P238-SENSOR POWER 3 CIRCUIT - VOLTAGE IS BELOW

NORMAL OR SHORTED TO LOW VOLTAGE POWER SUPPLY
P239-SENSOR POWER 3 CIRCUIT - VOLTAGE IS ABOVE NORMAL

OR SHORTED TO LOW VOLTAGE POWER SUPPLY
P689-ENGINE CRANKSHAFT SPEED / POSITION - DATA IS
UNSTABLE, INTERMITTENT OR INCORRECT

P731-ENGINE SPEED / POSITION CAMSHAFT AND CRANKSHAFT
ALIGNMENT ERRORS - MECHANICAL SYSTEMS ARE NOT

RESPONDING OR MISALIGNED
P2321-ENGINE CRANKSHAFT SPEED / POSITION - DATA IS
UNSTABLE, INTERMITTENT OR INCORRECT

Description

1 . The crankshaft position sensor is a Holzer effect sensor.The engine control
module (ECM) provides a 5V power to the position sensor through the sensor
power circuit. When the teeth on the crankshaft speed ring or the lobe at back
of the camshaft gear turns the sensor, the sensor generates a signal to be sent
to the ECM.The ECM identifies the signal and converts it to an engine speed
reading, and then determines the engine position according to the missing teeth
of the speed indicator ring.
Circuit Diagram

Page 318