Idling speed too high
Read the instructions below then
start the fault diagnostic procedure.
Symptom: Idling speed too high.
Fault symptoms
Idling speed too high.
Conditions
The following conditions apply for the current fault symptom:
|
•
|
No diagnostic trouble codes in the car with the current symptom description.
|
Note
|
|
Idling speed is always higher when the engine is cold and briefly after starting.
|
|
Diagnostic help
First, check that the pedal arm returns completely. Then, make sure the throttle body has not gone into limp-home mode without the control module being aware of it. This may occur if a throttle fault has occurred and diagnostic trouble codes are cleared or if the control module is de-energized without resetting the mechanism. After that, check for air leaks after the throttle. The additive fuel adaptation generally exceeds 4 mg/c if such a fault occurs. A high negative adaptation usually means the purge valve is stuck open.
Functions in the diagnostic tool related to the fault:
|
•
|
Idle speed control, unit ON/OFF.
|
|
•
|
Idle speed difference, unit rpm.
|
|
•
|
Additive Adaptation, unit mg/c.
|
See also description of test readings,
, for more information.
Checking the wiring
Jiggle the wiring harness at several points and in different directions to detect intermittent breaks and short circuits. Observe the multimeter, diagnostic tool or test lamp during the check.
