Idle Speed Slow Return To Normal Idle (2.4L) - Chery Tiggo 2009 Service Manual

ELECTRONIC ENGINE CONTROLS - 2.4L ENGINE SYMPTOM DIAGNOSIS
Idle Speed Slow Return To Normal Idle
The following conditions apply to this symptom:
• Slow return to idle.
1.
PRELIMINARY CHECKS
• Carry out the following preliminary checks:
− Vacuum leaks
− Intake air system
− Throttle body
Are all checks OK?
Yes >>
Go to the next step.
No >>
Repair as necessary.
Verify the symptom no longer exists.
2.
CHECK ECM DTC
• Turn the ignition switch on.
• With the scan tool X-431, read the DTC.
Are there any DTCs present?
Yes >>
Repair as necessary.
No >>
Go to the next step.
3.
CHECK PCV VALVE
• Remove Positive Crankcase Ventilation (PCV) valve and shake it.
Does PCV valve rattle?
Yes >>
Install PCV valve, go to the next step.
No >>
Replace the PCV valve.
4.
CHECK PCV SYSTEM
• Start engine and bring to normal operating temperature. Disconnect crankcase ventilation hose from PCV valve.
Place a stiff piece of paper over the hose. Wait 1 minute.
Does vacuum hold paper in place?
Yes >>
Verify test results. If OK, see diagnostic index to repair any additional symptom.
No >>
Check for vacuum leaks, obstructions in the PCV system, oil cap, PCV valve, rocker cover bolt
torque/gasket leak. Repair as necessary.
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Chery Automobile Co., Ltd.