Diagnostic Aids

WARNING: This page is about a different car, the 2002 Saturn Vue. However, it is still accessible from the selected car via links, so may be relevant.

Verify ECM's ability to control engine RPM by using ENGINE SPEED CONTROL in SPECIAL FUNCTIONS section of scan tool. This allows idle speed to be increased and decreased in increments of 25, 100 and 500 RPM. ACTUAL RPM should be within 100 RPM of DESIRED RPM.

Make an underhood visual inspection first. Possible causes are:

Air induction tubing cracked, damaged or loose.
Carbon around throttle plate/bore.
Accessory drive component loading engine.
System voltage low.