PCS Main modulation solenoid, interference
â–¶ How to fix
Check the cable harness between gearbox and control unit. If no fault is found, contact an Allison dealer.
What you'll see
No driver-visible symptom recorded.
System reaction
The Allison fault code number is: P0961.The fault code is set when the control unit detects interference in the main modulation solenoid return circuit for more than 2 seconds.The control unit shuts off all solenoids.The fault code is cleared automatically, when the vehicle has completed 40 start-up cycles without the fault being detected again.
Diagnostic depth
Detection
The control unit has detected interference on the return circuit for main modulation solenoid.
Possible cause
A possible cause of this fault code is a damaged cable harness in the solenoid return circuit.