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b) Whether the oxygen sensor installation is in place - may affect system's judgment of the air-fuel ratio.
c) Engine fault indicator - impacts system failure alarm
d) Battery voltage - to determine the adequacy of battery power
e) According to experience to judge whether the displayed value of coolant temperature sensor, intake air
temperature sensor, intake manifold absolute pressure sensor and oxygen sensor is normal
f) Operating range of the throttle position sensor - that it cannot be fully opened or fully closed may affect
engine dynamic performance and some system functions
16.4.2.2 Step 2
Whether the ECU power supply is turned off - communication between the diagnostic apparatus and system is
terminated after the key switch is turned off.
16.4.2.3 Step 3
a) Coolant temperature and coolant temperature cycling - indicates whether the thermostat is working
properly
b) Battery voltage - indicates whether the generator is working properly.
Too high: It may be the generator regulator failure;
Too low: It may be the improper generator connection or generator failure
c) Intake manifold pressure - may indicate whether there is leakage in inlet air and problem for valve
clearance.
Valve clearance is too small: this value is on the high side; it may affect the power of the engine, and
because of the exhaust valve too early to open, that the exhaust temperature increases greatly shortens the
life of the oxygen sensors and catalytic converters;
The valve clearance is too large: it will cause the intake manifold pressure is on the low side, and impact
judgment of the system on the engine operating state, resulting in idling exception while warming up the
enginecycle.
In addition, if the exhaust system is blocked, for example, foreign body presents in the exhaust passage,
excessive oil consumption resulting in clogging catalytic converter and blockage resulting from the
internal fragmentation of the catalytic converter, and it will cause this value is too high.
d)
Number of cycles of the oxygen sensor values - too little number of cycles, indicating the oxygen
sensor failure.
16.4.3 Concise troubleshooting
Please repair fuel injection systems according to the following sequence of steps; if troubleshooting can
be finished in some step, the follow-up steps may be omitted. And then with use of diagnostic equipment,
make inspection and erase the fault code according to 14.4.2.
In use of diagnostic equipment, the battery voltage is not less than 8.5 volts.
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Table of Contents
Troubleshooting
