ehammett

Its a long story but I'll make it short as possible. Completely rebuilt tranny and new TC @ 235k 10 months ago now I have 260k. I pull a 6000# camper unloaded.

I never had any problems until the day got back to North Carolina from Colorado. As soon as I drop my trailer and drive somewhere it starts acting crazy I'll get to 45mph and in 4th gear TC will lock up but if im not accelerating and want to stay 45-50ish it will unlock, not drop down into 3rd, but unlock. Around 60 it will do the same, as long as i'm on an incline or accelerating she's fine, stop accelerating or level off to not use as much fuel it kicks out instantly.

I have left the batteries off for hours and it has solved the problem for a week then it goes back. I have cleaned the battery terminals (they are only 8 months old) extremely well as well as ALL the battery connections. I have put one of the noise filters on and it was better for a little while then got bad, i have shielded the alternator ground with aluminum foil and aluminum tape.

I have done everything I can think off but spend a LOT of money to "try" something.

For giggles I changed the tranny fluid and test drove.. no better. I removed the noise filter and drove for 3 weeks with no problems, yay i fixed it!!!

Nope..... I drive to michigan to pick up a new trailer. Did great up there and back..... Same thing, i drop the trailer and the next morning I go to work and its back to its old habit.

I took the battery cables off again and let it sit for a few hours, now it is twice as bad.

What would you try? I have been getting an APPS code for a couple years but its never shown any signs of being bad or is it now?

Open for all suggestions!

phox_mulder

Since unplugging the batteries has an effect on it, have you tried the basic APPS reset procedure?

https://www.dieseltruckresource.com/...n&onlynewfaq=1

Perhaps, the 2nd time you unplugged the batteries you didn't go all the way down on the go pedal, so it didn't reset properly.

Then theres the much more involved procedure of adjusting the voltage:
https://www.dieseltruckresource.com/...n&onlynewfaq=1

I'd say if you've been getting the code for a while, then the unit needs replacing.


phox

ehammett

I did the reset APPS procedure and so far so good.. we'll see how it goes thanks

ehammett

Wel everything is still working just as it is supposed to however out of curiosity I thought I would check the voltage of the APPS.

The back of the sensor shows .507VDC and I was reading .18!

The good news is I found it it is not the proper voltage but the bad news is the most I can get out of it is .24VDC so what do I do now, do i need a new APPS or is there something else to try?

Russ Roth

My APPS is way off like that. In fact, it would change every time I bolted it down again. I finally gave up trying to get it close. Bolted it down and just let it set wherever it ended up. Reset it with the push to the floor deal. That was probably a year ago and it has been fine.

ehammett

So having this proper voltage isn't really that big of a deal? I always have the APPS code show when reading the OBDII saying the output voltage is low and now I know why. I have drilled a hole in it and sprayed the contact cleaner, that's why it was off the first time.. had no idea the holes were slotted for adjustment... maybe I can make the slots wider lol

Anyway, what would ti do for me to have the correct voltage/adjustment. The truck runs as fine as it ever has with no problems at the moment, if it were to put out .5vdc what should i notice different?

hamilton71801

Mine shows .518 on the rear of the Apps but the voltage was 1.05. Adjusted it to .52, did the Apps reset and threw codes. I did the reset several more times and finally gave up and reset it back to 1.05 and does fine so far. I'm clueless.

ehammett

Yeah, I can only get from i think .01 to .240 thats a very small range but its the most variance there is and it was set on .18. I have had the APPS off before and did not know about this adjustment (to drill the hole and shoot contact cleaner) so when I put it back on it set for .185.

Anyway, I'm guessing the thing may be bad since I can't get the proper voltage but it only acts up sometimes?

F.O.S.

I had the same thing happening to my truck that you listed above and after six months of trying everything I read on hear and with no permenant fixes I broke down and bought a new APPS. Keep your receipt as after I installed the new one it went bad less than a year after and I exchanged it for another. So far about two months on my latest one and no problems.

Russ Roth

I really have no idea if it's a big deal or if they are no good. I thought it was probably no good but I just figured I would "run 'er until she develops." So far it has been fine and not developed into anything so I will just continue to run it as is. Mine shows no code relating to the APPS.

Fishin2Deep4U

What if any fueling or electronics mods have you made?

I am familiar with the unlock at light throttle..

Dave

ehammett

Edge Comp & mechanical gauges.

New Starter 9/06
New Transfer Pump 9/06
New Injection Pump 11/06
New Batteries 12/06
New Tranny/TC/Electronics 11/06

Other: Radiator, Hoses, brakes, rotors, heater core, 9-12/06

Thats all

Fishin2Deep4U

With my truck, the Smarty made cruise lockup come in at 50mph.

Now, you could have a completely different issue. My Edge box gets lockup at around 37mph.

There is a couple of "idle" switches in teh APPS. Sometimes with fueling mods, advancing or raising the APPS voltage will keep the PCm with enough voltage to hold the lockup signal.

It is possible it's a bad APPS as well.

Dave

ehammett

So too low of an APPS signal, could fool the PCM into believe that it should unlock at incorrect times?

hamilton71801

Could stage 3 injectors alone (SC turned off) make it lock/unlock and throw "Apps low voltage" code? Mine does it every now and then and sometimes even defuels for a while.