Check fuel injector
Check fuel injector, injector
dirt, and repair or replace as
necessary.
Check coolant temperature
sensor
Check coolant temperature
sensor and connector, repair or
replace as necessary
Check intake air
temperature pressure
sensor
Check intake air temperature
pressure sensor
Check oxygen sensor
Check oxygen sensor, And
replace if damaged.
4.4 High Idle Speed
Check fault
codes
Determine fault sources
upon diagnostic codes.
Check air intake
system
Vacuum leakage
1 hose connection
2 throttle valve body
intake air valve
3 intake manifold
installation
Check throttle
position sensor
Throttle position sensor
and connection, repair and
replace when necessary.
Check step
motor fault
1 check step motor coil
resistance
2 when warming up and
engine idle, use scan tester
to read step motor total
steps, and adjust the idle
screw till total steps is
20-40
Check coolant
temperature
sensor
Check coolant temperature
sensor and connecting
wire, repair or replace as
necessary.