General TPS Requirements

I don’t have a spec unfortunately, generally it’s not something a guy needs to worry about as long as an automotive sensor is being used and it’s wired up properly. I will try to measure a variance at some point that I think would cause a problem and edit this reply.

In odd applications that need a signal made by an electronic device (like engines that have electronic cruise control which require my “TCR” module to emulate the throttle signal for the trans system) it hasn’t been a problem either, the device I use outputs the signal in 16 bit resolution. I would not recommend using any such device unless it is needed, for most applications a standard throttle sensor is what I would recommend.

There are some 5 volt hall effect sensors out there made by Honeywell and possibly others that would possibly be an improvement but they require special mounting considerations. They do not work when mounted to magnetic material.

Quoting the earlier post above, just in case you missed it:
“A huge FYI for anyone who doesn’t know already – when the Allison system does not get a real TPS signal, or is not programmed to get one from a sensor, the signal will be faked according to rpm – so while the engine is running the system will always show signal – but still may shut down converter lockup, and shift quality will often be quite poor. The only way to know you are getting a good signal is to check for it with EFI Live or some other scan tool with the key on and engine off.”

To add to that, another indication that the system is not getting the throttle signal is it will limit out at around 64-69%. The 8.1 system, using the CAT PWM sensor will still limit out about there even when that signal is actually working. That is the only type of signal that I could set up an A40 for, or possibly an A50 as well if a full flash 8.1 calibration could be found. I don’t recommend using those for reasons I won’t list out here, but if a person insisted on wanting to try one I would help them if needed.

Other MD TCMs may work but I require potential customers that think they may have the right one to send me a picture of the back of their TCM, and I only give them one chance at that :). Some guys love to poke tons of questions at me and spend tons of time to figure something out “on their own”, only to save a $100, and it makes me understandably grumpy. Even if someone has the “right flavor” of TCM, sometimes the TCM does not have the right operating system to be compatible with my tune library, so there is still a chance that I couldn’t work with it.

If the TCM is programmed to get TPS over J1939 it will not work for an analog sensor without being reprogrammed. There are some rare ones that are AutoDetect – those potentially could work for either sensor source, but those are so rare for a 1000-2550 series that I would be really surprised if anyone found one.

The TCMs I use for a stand alone system are different than A40 or A50s. However, if it happens to be one that can be reprogrammed for analog tps source, and it has the right OS, then yes it could be used. What they are exactly is info I don’t shout out to the public, but on occasion I have sold just the TCM before with info to modify the harness for a very fair price.

The range inhibit code sounds like it could be a second and unrelated issue, but in a situation like this, get the throttle signal solved and then a person can go from there.