Solenoid PCS4 jammed in disconnected position
â–¶ How to fix
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 detected slipping in clutch C4 which PCS4 supplies with hydraulic pressure.
Possible cause
The cause can be: Erratic sensor signal from turbine or output shaft speed.Leak or obstruction in C4 supply circuit.Faulty PCS4 solenoid.A governor valve for PCS4 is stuck.