Allison WTEC II Fault Code: 63 PID: SPN: 00 FMI: Input function fault

Code 63 00 is set when one of the two inputs for an input function Auxiliary Function Range Inhibit (Special) is in a different state (on or off) from the other input for longer than two minutes. When this condition is detected, Code 63 00 is set, the Service Indicator output is turned on. The transmission will not be inhibited in shifting from neutral to range.

If Code 63 00 is set and the ECU was programmed after 9/26/94, the SERVICE icon on the shift selector will be illuminated.