Tommy93w350

Ok, thanks for the feedback.

I do remember taking the TPS off my 93 cleaning it, setting the voltage, pulling wires from the loom, and adjusting it until it worked. Once I spent the time on it doing the following, it never messed up again.

Viesel

Well I really need to get this thing fixed. Its absolutley irritating, all day I am driving around and it is non stop in and out of lockup. Its got to be hard on the trans. Is there another switch somewhere that could be the problem. I would rather try R&Ring swithes then to R&R the trans for VBs and such. Anymore ideas on what else it could be would really help. If I dont get it fixed I might get mad enough and go trade it in, and I cant afford that right now.

Geico266

What have you tried? I fixed 80% of the problem by resetting the APPS to the correct voltage.

piperca

Viesel, Geico266 is right! I was having a problem with my truck and a combination of adding a DTT noise filter and an APPS reset fixed the problem. Here's the link to the APPS reset: http://www.dieseltrans.com/phpBB/viewtopic.php?t=614 Our trucks are famous for having an electical noise issue. I have seen quite a few people post regarding this issue lately.

RickCJ

Did you read my 1st post? Do you know how to ground the tc lock up circut? You may have a bad tc clutch! You need to find out if it's the clutch or an electrical issue. Try hooking up a mystery switch and see if it slips or not.

Viesel

I will have to find out how to bypass the switch and try to see if it is the tc or electrical issue. Where do I find the info for the tc switch for adding a temp switch.
Yes, I replaced the apps and reset the new one and still the same.

Marine

Look in my gallery. I have it posted there.

piperca

Viesel, try looking at the end of the following thread, Barracuda has some excellent points, which didn't cost a lot. He replaced/added a couple of ground wires, which solved his problem.

https://www.dieseltruckresource.com/...ad.php?t=81095

Good luck and keep us informed!

Geico266

Here are the instructions copied from Barracuda's post. IT WORKS!

OK, I took a look last night at the wiring I had did for the extra ground..First thing you will need to do is remove the factory air box to get access to the PCM and disconnect the batteries as a precaution b/c you are playing around the PCM, you will notice their are (3) seperate connections going into the PCM w/ multiple wires in each one. The one you will need to work with is located furtherst right (3rd one over, closest to the drivers side) , you will find (2) wires which are both ground wires, they are black w/ tan tracers and are located right next to each other . Once located, use a "scotch-lok" type connector to attach to one (or both if you choose) to the wire that will run to the battery (i used a 14 awg wire, i do not think that is critical), they are small wires and you do not have a ton of room so be careful not to rip the wire from the factory plug, i pulled the plug from the PCM to make it easier . Run the wire over to the passenger side battery and make a good connection to the Negative battery post (clean ALL terminals of all batteries at the same time), you are done! I had tried the "re-flash" from the factory to cure this problem and it worked for a week, tried the "APPS Reset", didn't work at all. I will tell you that I first ordered the DTT noise filter (about $30) to cure this problem, I hooked it up and it helped but did not totally cure the problem and about a week after that I ran the extra ground and for around 8 months it has NEVER once acted up, the reason I am telling you this is I can not say for sure if the ground itself TOTALLY cured the problem or if both needed to happen to ultimately cure it. The ground makes a lot of sense if you think of the root problem causing the erratic TC lock and un-lock, if you find you need to do both, contact DTT Transmission and get the noise filter too, it is well worth the $30.....Please let me know if the ground alone cures your problem, I am very interested to know if I even needed the DTT filter...Good luck, let me know if u have any other questions.

Extra300

As I posted before, I have also purchased the DTT filter but I also ran a jumper wire from the computer to the APPS. My transmission man found the recommendation in one of his diagnastic manuals for this problem. As stated, 1. remove the air box, 2. of the three plugs you find, remove the one closeat to the driver, 3. locate the orange wire with the blue tracer (this is also the one DTT instructs you to splice their filter onto), cut this wire at this end, 4. if you have the DTT filter, solder it along with another 16 GA wire long enough to reach the APPS, or just the jumper wire, 5. remove the three bolts holding the APPS bracket to the block and unplug the unit, 6. locate the light blue wire with the black tracer, 7. (do not cut this wire) splice this wire onto the wire you have ran from the computer, 8. reinstall everything. All that took me about an hour. That, along with replacing all my OEM battery cable ends and cleaning the grounds has fixed my problem. Here is the order in which i kept doing things to fix this problem. It got better with each step and is now working perfectly. I am at 215,000 miles and counting.

1. New VP44, new APPS, and added a second in-line LP (to fix dead peddal)
2. installed DTT noise filter
3. cleaned all grownds (as DTT recommends)
4. added jumper wire which I described
5. replaced all OEM cable ends

Problem has not reoccured. Finally, once again a joy to drive with my Superchips installed.

dozer

the switch on the back of the brake pedal will unlock the TC when you press on the brake. Sometimes the return spring on the brake pedal will wear out and every bump you hit on the road will cause the pedal to bounce and triger the switch. Or the switch can just go bad and cause problems. A new switch is about $14 at napa.

OKIE99

66GTO
Member
Member # 5129

Rate Member posted July 23, 2005 02:11 PM
--------------------------------------------------------------------------------
If it's your TC locking & unlocking........

just fixed my 1999 with the exact same problem.
I learned the ONLY thing that time changed was corrosion. PERIOD! After wrestling with YOUR VERY PROBLEM for over a year now (I've done it all at 172,000 miles on my 1999) I FIXED THE PROBLEM the following using common sense and LOGIC.
#1. Forget a filter of any type.
#2. Forget about rewiring any wiring braids.
#3. Forget about reflashes.
#4. Forget about electrical loads

Your truck ran great for how long without the above filter additions, wire loom changes, computer reflashes or electrical loads.
Your computer and T/C worked well before WITH your electrical loads, without any filters, without computer reflashes. Use your common sense. What fixed MY truck.......drumbeat please.............was that I cleaned, to BARE SHINY METAL, 3 points. Each NEGATIVE battery post has a smaller black wire you will see goes to nearby sheetmetal. REMOVE SCREW and clean metalto BARE METAL. I took both screws and held them with pliers and held them at a wire wheel till they shined. THEN, at your PCM (on firewall behind your stock airbox) you will see a black wire, and on my PCM this black wire was on the bottom right. Remove this long screw, CLEAN PCM SURFACE where the black wire mates to screw, and of coarse CLEAN THE LONG SCREW TILL IT SHINES. With the very small voltages your PCM works with, a weak ground, CAUSED by a bad corrosive connection, will cause signals to seek or bleed to other areas. Please know electricity, like water, will search for the EASIEST ground path and thus will be affected by other high current draws (AC/Defroster mode, etc.) Everything electrical is competing for a ground, especially high current loads. Like in life the little guy loses. All this filter does is to lessen the impact or sensativity ALL CAUSED BY A WEAK GROUND. Same goes for the reflash. So goes with the bad bad wire loom that contains the alternator high amp wire. MAKES SENSE, AND IT WORKED FOR ME. All things on my truck were the same, except for weak ground points. Now those 3 points on my truck are the same as new!
What can it hurt to try ???? If you are super **** you can even run a new special wire from the PCM ground point right to your negative battery terminal. I did not have to do this as I returned my truck to like new conditions by eliminating corrosion.

--------------------
"66 GTO..Get in, Sit tight, Please Hang on"

Extra300

We bow to your superior wisdom and 'logic'. However, I wouldn't ignor the fact that, as parts wear (alternator), and all connections age, signal wires bundled together with alternator wires could, after years of use, develope problems that weren't apparent when new. This whole system is very voltage sensitive. Ever wonder why your AM signal isn't as clean as it was when the truck was new. Your computer is getting the same crap your radio is getting. Just because something worked great from the factory, doesn't mean it is right, or that it will always work right. Your lift pump probably worked great for some time also, but now, when it pukes, and it will, the dealer can't even offer you that pump, because of all the problems they have had. You go to him, and he will stick a different pump in your tank.

One thing is for sure, in spite of all the research and experimentation with fixing this problem, the final and permanent solution isn't expensive, but it will take some of your time. Even DTT (the producer of the noise filter) tells you, right up front, to expect 4 or 5 hours in cleaning all those years of corrosion off your electrical connections.

Geico266

I have to agree with both Okie99 & Extra300. I have cleaned up the grounds, ran new grounds, scraped grounds to bare metal, installed filter, reset APPS and I still have a problem, but it is now very intermitant.

I am going to redue all grounds again and see if I missed something. This is a furstrating problem.

Extra300

Don't forget to clean or replace your hot connections as well. My problem was not totally gone till I replaced ALL of the OEM battery cable ends with new ones. Sounds like you're close to getting it licked. Driving these things becomes fun again when you get past this problem, and you will.