Engine Electrical System

11) Periodically instability (the memory has to be restored after ECU’s
power-off)
Yes
Fix the indicated
malfunction.
1
Turn the ignition switch to “ON” position.
Inspect with the diagnostic tester to see
whether there is any malfunction
information record.
No Proceed to next step.
Yes Proceed to next step.
2
Verify that the air filter is free of any
blockage.
No Replace
Yes Proceed to next step.
3
Verify that the air intake pressure is
maintained between 35-65 kPa at idle
speed.
No
Overhaul air intake
system and leakage.
Yes Proceed to Step 7
4
Run the engine at idle speed and cut off
the cylinder one by one in order to verify
that the speed is decreased and fluctuated.
No Proceed to next step.
Yes Proceed to next step.
5
Turn the ignition switch to “ON” position
and connect the adaptor between ECU and
the wiring harness. Verify that the
voltages at following ECU’s pins
including absolute pressure sensor output
of air intake manifold, air intake
temperature sensor output, coolant
temperature sensor output, oxygen sensor
output, electronic grounding, ignition
switch pin, and ECU’s pins of 65#, 64#,
67#, and 66# (output connected to idle
actuator) are normal.
No
Repair or replace the
wiring harness.
Yes Proceed to next step.
6
Run the engine at idle speed until the
coolant temperature reaches its normal
value in order to verify that the ignition
advance angle is normal.
No Inspect other items.
Yes Clean
7
Verify that the sensing holes of air intake
manifold pressure sensor and air intake
temperature sensor have any blockage.
No Proceed to next step.
Yes Replace the fuel.
8
Verify that the fuel is deteriorated or
contaminated with water.
No Proceed to next step.
Yes Proceed to next step.
9
Apply a voltage supply of 12V directly
between the battery and the fuel injector
with special connector, and verify that the
fuel injector functions normally.
No
Overhaul the fuel
injector and relevant
wiring harness.
Yes Proceed to next step.
10
Verify that the resistance of each cylinder
high voltage cable is normal.
No Replace
11 Verify that the ignition coil and high Yes Replace
E-79
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