ok my truck has a strange problem that nobody can seem to figure out i have posted on this subject before and have done all the suggestions but they dont help so i have payed close attention to exactly what it is doing and from this info maby someone can help me fix this problem because the dealer cant fix it and im tired of replacing parts to try to fix it and it dosnt help. first i have cut off the gray connectors on the pasengerside by the battery tray and soldered the connections and shrink wrapped them i have also replaced the altinator and i have cleaned the battery terminals and replaced the vp44 and transfer pump all of this needed to be done and all of these problems happened all at once including the transmission acting up at what seems exactly at 35mph. ok this is what its doing and i need to know what will fix it and if it is doing damage by driving the way it is now the APPS is $504.00 and would not like to replace it if necessary especially if it not going to fix this particular problem. when i am going 35mph the tc is locking and unlocking and the throttle is very sensitive if i just very lightly push the accelerator down to gain speed slowly the the tc will lock up and stay locked until i let off the petal and it will do it all the time if i am just maintaining 35mph is locks and unlocks constantly and when the trans switches from 2nd to 3rd it seems like the tc stays locked up after the switch from to 3rd until i let off the gas it only dose it at 35mph and the auto trans guy at the dealer says there is no mechanical failure with the trans and dose not know why its is so sensitive and suggested to replace the apps just like he said to replace the alternator because i was getting what he called electrical noise. sorry for the long post but this problem is driving me crazy and i dont want to damage the trans so any help would be appreciated and if someone could tell me if this is hurting the transmission.

 

Where are you located?

 

i am located in Washington

 

As you have experieced chasing this prob down can really bite. If you can make it happen 90% of the time, try unhooking the alternator (yes, I know it's new) and test driving and see what happens.

 

will do. by the way when i had it at the dealer i told them to go through all the grounds and they said that b4 they could check the grounds the alternator had to be replaced dose this make since to anyone

 

There are many solutions for this. I believe if you read enough about it you will find that the loom holding the APPS wires to the ECM is the same loom that carries the altenator wires. The problem is that the altenator wires are creating electrical noise in the APPS wires. Some fixes are to pull the APPS wires out of that loom of wires and route them to the ECM away from that loom. Another fix I have heard of is placing a noise filter in the APPS wire. I actually put a ground from the APPS housing by tapping the hole in the front of the APPS housing and runnng it directly to the Negitive battery terminal on the Drivers side battery. I have had this settup for over 2 years now and it has never happened again. Good luck.

 

i'm having this problem also. exactly where did you tap the housing Magaliasram? doesnt look like theres much room.

how does this problem happen after 5yrs?

 

what about hurting the transmission is bad for the tc to lock and unlock like that dose it wear it out is it damaging my trans?

 

I had what sounds like an identical problem. I tried a number of the fixes that often work, but they didn't help. Two tranny shops said it was an electrical problem, and one of them tried to fix it by replacing the APPS. That didn't help. I did two things at once the day that the problem stopped - I exercised the brake switch several times and I put an RF choke on the black wire with tan stripe that runs by the alternator. I put the RF choke between the alternator and where the wire runs to the passenger side of the engine bay. Frankly I don't know why putting the RF choke there would help and I wonder if my brake switch was the real problem. I got both ideas from members on this site. The RF choke is just a ferrite core that you snap on around the wire, and if there are electrical "spikes" it creates an opposing magnetic field that "chokes" out the spike (supposedly). I don't know if these will fix your problem but they seem to have fixed mine, unless it just randomly stopped. It has been 5-6 months since the problem last happened, and it was happening every day or every other day. Good luck!

 

I've also cut the field wires for the alt and made a new twisted pair harness for them and ran them straight to the JTEC controller. Only thing with that is you also have to run a new wire over to the trans relay as the B+ output for the alt field also goes to the trans relay (blue wire). Green wire is the one the JTEC grounds to full field the alt.

Removing the brushes and cleaning them, or replacing them and cleaning the surface where the brushes ride has helped on some too.

 

I had the same problem off and on since I bought my truck in '99. Usually a reflash fixed it, but finally the last time it happened the dealer said they couldnt fix it. I was po ed. I had a fit and explained to them that when I paid 41k for the truck I expected it to last a while. Anyway to get me out of there the service manager told me about this thing you buy off the internet its called the Happi box. Its some kind of filter that hooks into the wiring going to the ecm. I bought it and its the best money I have ever spent. I have had it on my truck for 2 years and never had the problem again. I have heard that one of the performance transmission guys sell something like it for a much cheaper price. If you cant find something from them I would sure suggest that Happi box. I am very happy with it.

 

....the "happy box" didn't work on one truck I had issues with. Problem with this rfi deal is there seems to be many different issues that can "correct" this prob.

...I've had a couple guys get po'ed because this issue "came back" after we attempted a repair. I make it as clear as i can that any attempt to repair the prob "MAY" correct the issue. Nobody likes to hear that, but that's how it is. I often refer to this site and show them how many people have the same issue and how difficult it can be to pinpoint. So far my 01.5 has never suffered.

 

no body has mentioned anything about damage to the tc or trans in any of these threads i posted or post that i have read. dose it hurt the transmission??????????????

 

oh and what would be a better to try first the electrical noise filter for $39 or the happy box and how much is a happy box and where do i get one?

 

i had the same problem. this is what fixed it for me and a few others who had the chronic problem of it coming back. Hardest part is opening the hood.https://www.atsdiesel.com/PDF/120505...%2047%20RE.pdf