Toyota ZZT230 series, Repair Manual

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0114
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ENGINE
DTC
P0300 Random/Multiple Cylinder Misfire Detected
DTC P0301
Cylinder 1 Misfire Detected
DTC P0302 Cylinder
2
Misfire Detected
DTC P0303 Cylinder 3 Misfire Detected
DTC P0304 Cylinder 4 Misfire Detected
CIRCUIT DESCRIPTION
Misfire: The ECM uses the crankshaft position sensor and camshaft position sensor to monitor changes in
the crankshaft rotation for each cylinder.
The ECM counts the number of times the engine speed change rate indicates that
misfire has occurred. And
when the misfire rate equals or exceeds the count indicating that
t
h
e engine condition
has
deteriorated, the
Mil lights up.
If the misfire rate
is
high enough and the driving conditions will cause catalyst overheating, the MIL blinks
when misfiring occurs.
DTC No. DTC Detecting Condition
Trouble Aiea
• Open or short In engine wire
• Connector connection
• Vacuum hose connection
• Ignition system
P0300 Misfiring
of random cylinders
is detected during any particular •Injector
P0301 200 or 1,000 lliVOiutions • Fuel pressure
P0302
For any particular 200 revolutions lor the engine, misfiring is • Manifold absolute pressure sensor
P0300 detected which can cause catalyst overheating
• Engine coolant temp. sensor
P0304
(This causes
Mil lo blink)
• Compression pressure
• Valve clearance
• Valve timing
• WTl system (locker atm)
•ECM
HINT:
When the 2 or more codes for a misfiring cylinder are recorded
repeatedly but
no
random misfire code is
recorded, it indicates that the misfires were detected and
recorded
at
different times.