Fault code 128 091 03. Replced throttle potentiometer no change What next?
It might help to know what model engine you have. A Serial Number would be even better. Is the throttle position sensor analogue or digital..? Part Number you installed..?
Stab in the dark here... Does your truck have dual speed sensors or a 4 wire dual coil speed sensor on the transmission output? Good possibility one is bad, Usually with dual sensors one runs the speedo and the other feeds the ECM cruise info. It would still help to know what you have.
Sorry, 2001 357 Peterbilt,N14 Cummins. Replaced Bendix 5002377. H290026. Don’t know about the system I have. I wondered if there was a separate sensor for the cruise as the speedometer works great. Check engine light came on and the cruise quit. We have seen 3 sensors on the transmission,back,center,front. Figured the back one to be the speedometer sensor,unplugged it and no change in the code. If we unplug the throttle potentiometer the code changes to a 4.
Rear of trans has sensor with 2 wires, speed I am guessing, 2 other sensors on side of trans. 1 about half way back and the other towards the front,both on the right hand side.
Now it would help to know what your transmission is.
Allison 6 speed automatic, I will have to get the model number. Had it but can’t find where I put it.
The 128 091 code is for your tps you just changed you have a wiring or connector issue most likely, 128 identifies it as a general engine fualt , an alisson fualt would start out 130 i belive but you can get codes from your trans thru the shift pad. The rear sensor on trans is road speed for speedo and cruise front sensor is basically engine speed and middle one is turbine speed. You have a problem somewhere in throttle circuits cruise switches are part of that .
Model number of transmission is HD1560. Serial number is 6610072022
Thank you for your reply. We started checking wiring today and will continue tomorrow. We have found several areas that have rubbed going over the top of the transmission. Don’t think we have found the problem yet.
Probably alisson hd4560 model. Around tranny and rear engine mounts and rear spring hangers is were i usually find harness problems on my macks , where its real fun to try and fix enter sarcasm anywhere in that sentence lol. Peterbilts im not to familier with as far as where the problems end up being in the harnesses but we have a few so im sure to learn it eventually.