Idle Speed

Idle speed is controlled by PCM and idle speed control air by-pass valve on all engines. On most models, engine idle RPM is fixed and cannot be changed by standard adjustments. A scan tester must be used on these systems because control strategy and idle speed specification are controlled by PCM. See IDLE RPM SPECIFICATIONS.

Before performing idle speed adjustment procedure, complete a thorough basic inspection and self-test (KOEO, KOER, Continuous Memory self-tests) to confirm operation of sub-systems contributing to idle speed control. See QUICK TEST in TESTS W/CODES - EEC-IV article in this section.