Coolant temperature sensor (T79), voltage high
â–¶ How to fix
Check the cable harness between the coolant temperature sensor and control unit pins 58 and 35. If no fault is found, contact an Allison dealer.
What you'll see
No driver-visible symptom recorded.
System reaction
No system-reaction text recorded.
Diagnostic depth
Detection
The control unit has read a coolant temperature that is less than a calibrated value.
Possible cause
Possible cause of the fault code is an open circuit in one of the cables connected to pin 35 or 58 on the control unit. A short circuit to battery in the cable connected to pin 58 on the control unit can also cause the fault code.