Note On Intermittents
WARNING: This page is about a different car, the 1990 Cadillac Seville and 1990 Cadillac Eldorado. However, it is still accessible from the selected car via links, so may be relevant.
Code EO64 sets when vehicle speed increases more than 16 MPH in one second with cruise control engaged (4 MPH in .25 seconds). If code EO63 is set, cruise control will disengage and Code EO64 is stored in memory. Most occurrences of Code EO64 are caused by wheelspin due to icy or wet conditions. If Code EO64 is found and no other cruise control faults exist, clear codes and road test vehicle. If code sets without wheel spin, see CHART C1, ECM REPLACEMENT CHECK. When all diagnosis and repairs are completed, clear codes and verify operation.