Allison WTEC II Fault Code: 45 PID: SPN: 21 FMI: Open circuit, F solenoid circuit

Main code 45 indicates the ECU has detected either an open circuit condition in a solenoid coil or the wiring to that solenoid. The DO NOT SHIFT response is activated when this code is detected and all solenoids are turned off. DO NOT SHIFT light is not illuminated.

If solenoid resistance is about 1?2 Ohms, a short-to-ground code may not be set but could cause a burned-out solenoid driver in the ECU. Replace the solenoid when this occurs (see appropriate transmission Service Manual for replacement procedure). If the solenoid driver is burned out, 69 XX codes will be set. See the troubleshooting procedure for 69 XX codes.