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Skip426 · 08-20-2022, 03:18 PM

Quote:

Originally Posted by Scott526

Update - The manual showed me how to get into the diagnostics on the shift panel. It reported a 21 12 code and no other codes. This is "Throttle position sensor failed low and ECU signals 100 percent throttle". So, I called NAPA and they have a TPS for about $450. I locate the TPS in the coach and it looks nothing like the new one from NAPA. I found a youtube video that says new technology has replaced the old sliding contactor/resistor type TPS. Has anyone installed this new tech? I am concerned about taking the old TPS off before having the right part.

Your existing TPS is reporting continuous operation at full throttle , so the trans doesn't shift till the engine revs to the governed limit .
Removing the TPS will not change that ; it actually may make for short shifting .
Have you examined the TPS control cable to the engine throttle linkage , to ensure the cable isn't bound up on something ?
Do you have a NAPA part number or photo of the replacement ?
Is there any indication that wiring and installation instructions are included , with the up-dated part ?

Ray,IN · 08-21-2022, 02:56 AM

Allison states to use the touch panel to check fluid level, it is more accurate.

Scott526 · 09-13-2022, 02:25 PM

Quote:

Originally Posted by Scott526

Update - The manual showed me how to get into the diagnostics on the shift panel. It reported a 21 12 code and no other codes. This is "Throttle position sensor failed low and ECU signals 100 percent throttle". So, I called NAPA and they have a TPS for about $450. I locate the TPS in the coach and it looks nothing like the new one from NAPA. I found a youtube video that says new technology has replaced the old sliding contactor/resistor type TPS. Has anyone installed this new tech? I am concerned about taking the old TPS off before having the right part.

Problem Solved: The part I purchased from NAPA was an accelerator pedal position sensor, returned. After further investigation the pin that the slip link connects to was sheared off. The slip link is the connection between the TPS and the throttle linkage see photo. I was able to remove the linkage and weld a piece of all thread on to solve the problem. My supposition is that the slip link got dirty/corroded/twisted and cause the pin to sheer.