Main code 24 indicates the ECU has detected either a high or low fluid temperature in the transmission sump (via the sump temperature sensor in the internal harness). No upshifts are allowed above a calibration range when Code 24 23 is set. A related code is 33 12 which indicates a temperature reading outside the usable range of the sensor and indicates a probable sensor failure.
Allison WTEC II Fault Code: 24 PID: SPN: 12 FMI: Sump fluid temperature, cold
Allison WTEC II Fault Code: 23 PID: SPN: 15 FMI: Secondary Shift Selector Mode Function Fault
Allison WTEC II Fault Code: 23 PID: SPN: 14 FMI: Secondary Shift Selector or RSI Link Fault
Allison WTEC II Fault Code: 23 PID: SPN: 13 FMI: Primary Shift Selector Mode Function Fault
Allison WTEC II Fault Code: 23 PID: SPN: 12 FMI: Primary Shift Selector or RSI Link Fault
Allison WTEC II Fault Code: 22 PID: SPN: 16 FMI: Output speed sensor reasonableness test
