Diagnostic Aids

Code will set if engine RPM exceeds 6350 RPM with cruise control engaged. This may result from wheelspin due to icy, wet or slippery pavement, extended wide open throttle acceleration or mechanical problems such as transaxle slippage. Under these conditions setting of Code 66 should be considered normal.

Fig 1: Code 66 Schematic (4.0L) Cruise Control Engine Speed Too High