Engine/Transmission (1998.5 - 2002) new auto transmission problem

[sgoeing]

The auto on my 99 is acting really weird. It goes fine up into fourth gear, but at 45, when it should lockup, it does. But then it acts like it unlocks, and locks back up. It was unlocking and relocking exactly once. Now, it may do it 2 or 3 times until I get up to about 50mph. After that, no issues.



I'm wondering if it wasn't an issue with my low boost fueling setting on my edge attitude. I turned it back down, but I haven't tried it since turning it back down.

 

[fox]

It is most likely electrical noise getting into the computer. Clean the grounds. If that doesn't change it, do a search here on electrical noise or locking and unlocking.

 

[sgoeing]

That's so odd though. I haven't changed a thing since I put the Edge Juice in over a year ago.

In the last several months, I've changed absolutely nothing other than the transmission speed sensor which fixed a shift problem. I had no problems in the weeks since until now.

 

[sgoeing]

So is the APPS signal an analog voltage signal that varies directly according to where you hold the pedal?

If so, why can't I just put a capacitor on that line to get rid of any voltage spikes?

 

[Tom W]

The wiring and batteries are older. Weak batteries can contribute to this. First clean the battery terminals and see if it improves. Try the easy things first, don't make it any harder than it has to be.

 

[Timbeaux38]

Weak batteries will cause your truck to do all kinds of stupid crap

 

[sgoeing]

The batteries are less than a year old.

 

[DFerverda]

My truck, 1998. 5 same as your 99 did the same thing 2 weeks ago. I cleaned the battery terminials and All of the grounds i could find going to the engine and put electrical grease on all the connectors, It quit hunting and has been fine since.

Dirk

 

[sgoeing]

Well, I cleaned the battery terminals and strung a 1 Farad cap from the alternator to the passenger battery putting grease on everything. We'll see what happens when I drive it around tomorrow.

 

[DBuchheit]

I had the same problem. Disconnecting the batteries and cleaning grounds would sometimes help for a while, but it would always return. I finally broke down and installed a DTT noise filter. That fixed it for good. It's quick to install and I highly recommend it.

 

[FourBarR]

If after you do the cleaning of grounds (there are many of them in hidden places)installed the noise filter, wrap the black /brown ground wire from the alternator to right fender location . Have your codes checked,if you get p0121,p0122 or p0123 you need to change the APPS.

 

[sgoeing]

I had the same problem. Disconnecting the batteries and cleaning grounds would sometimes help for a while, but it would always return. I finally broke down and installed a DTT noise filter. That fixed it for good. It's quick to install and I highly recommend it.

I had a 1 Farad cap just sitting in the garage so I ran it right off the alternator to the passenger's battery and grounded to the battery.

I drove it to work this morning and around some tonight, and it's gone. I think the whole transmission is actually shifting more cleanly too. Mine must be noise from the alternator. I checked ebay too, and you can get a 1 farad cap for 20 bucks now. Hose clamps to secure it to the battery support were 5 bucks, and the tube of dielectric grease was another five bucks. 30 dollars total (including the cap which I already had just wasting away) is pretty good. DTT wanted 60 for that filter, and I bet my supplies throughout my system are cleaner than a system with the filter. (I hope anyway, because as much as I like improving things, I hate fixing nagging little problems).