Sanman

Hey just wanted to update on my situation and maybe this will help someone else, So I was able to solve the problem by getting lucky. It was actually the PTO switch itself, Even though the light turned on and turned on the hydraulics it’s not a regular rocker switch, it has a secondary part to it that’s attached from behind and looking from the front of it you would never know that until you take it out. Anyway the secondary part of it was loose and just had to be readjusted and tightened up.

LilMartian so your saying the problem could be in the transmission ECU ?

Hey Mackpro yes the PTO light goes on with the switch and its a automatic Allison transmission.

New to the site and wanted to say hi before asking for help, Im driving a 2015 Mack Granite RollOff with 41K on it and recently when I turn on the PTO it still always activates the hydraulic pumps but now is NOT disengaging the Idle shut down mode, is NOT activating the rev limiter and is NOT activating the governor to prevent the transmission from shifting past the first gear. If I had to guess i would say that the switch is not communicating with the Mack truck computer but is still communicating/working with the pumps themselves. Has anyone ever have this problem or heard of it and what can I do to fix it ? any help is appreciated and thank everybody in advance.