Maintenance manual for sunray hfc4da1-2c china-IV diesel engines
177
24.
DTC P0300 Multi-cylinder misfire
P0301 The 1
st
cylinder misfire
P0302
The 2
nd
cylinder misfire
P0303 The 3
rd
cylinder misfire
P0304 The 4
th
cylinder misfire
Fault Description: ECU determines when engine misfire occurs with the help of information from ignition control
(IC) module and camshaft position (CMP) sensors. ECU can detect single misfire via crankshaft speed change for
each cylinder. In the case of some vehicle running condition, too high misfire rate will lead to three way catalytic
converter (TWC) overheating. In the case of three way catalytic converter overheating, MIL will flash. If misfire rate
detected by ECU is enough to make emission level to exceed mandatory standard, DTC occurs. If diagnosis operation
fails in two continuous ignition cycle, control module lightens MIL. Control module records operation condition when
diagnosis is failed. For the first diagnosis failure, control module will keep this information in fault record. If
diagnosis failure occurs during the successive ignition cycle, control module records operation condition under
diagnosis failure and writes the operation condition in frozen fault condition and updates fault record.
Diagnosis Hint: Influence factors for misfire diagnosis—In the case of misfire diagnosis, it is required that all
vehicle parts are under mass production or equivalent. All changes which may influence engine crankshaft speed will
interfere with correct diagnosis for misfire.
In the case of faults in components as follows, misfire diagnosis will pause to avoid incorrect diagnostic
results—intake pressure/throttle position rationality fault; low voltage or open circuit of intake pressure sensor circuit;
high voltage of intake pressure sensor circuit; low voltage or open circuit of coolant temperature sensor circuit; high
voltage of coolant temperature sensor circuit; high voltage of throttle position sensor; low voltage of throttle position
sensor; signal interference of crankshaft position sensor circuit; no signals in crankshaft position sensor circuit; no
signals in camshaft position sensor circuit; camshaft position sensor rationality fault; high voltage or open circuit of
intake air temperature sensor circuit; low voltage of intake air temperature sensor circuit; no signals in vehicle speed
sensor.
Severe vibration which is not caused by engine may lead to setting fault (vibration source may lead to wears or
damages to brake discs with different thicknesses and additional drive belts).
To Next Page
Loading...