Engine Idle Speed Check

Engine Idle Speed Check (With the Throttle Positioner Application)

On vehicles that have curb idle speed adjustment capability, if the idle speed is too low, the engine will run roughly. An idle speed that is too high will cause the vehicle to creep, have harsh engagements and harsh closed-throttle downshifts.

Refer to the ENGINE/EMISSION DIAGNOSIS* manual for curb idle speed adjustment information.

On vehicles equipped with an Exhaust Gas Recirculation (EGR) system, it is important to check the system for proper operation and for a no restricted or leakage condition.