Engine/Transmission (1998.5 - 2002) torque converter unlocking even with torq lock switch on

[9412v9824v]

ok so i bought a 24 valve cummins 1998. 5 ive always been a 12 valve guy but figured id give it a shot. well like my 12 valve i wanted to hook up a torque lock switch. in the 12v you flip the switch and the converter locks up and you know it. but with the 24 valve i flip the switch and you can tell it locks up (not as much as the 12v) but when you get into the throttle the converter unlocks... . i have read up on all the ground issues with the pcm. . i also unhooked batteries for 15 mins and hooked them back up turning key on pushing throttle to the floor and letting back up. i test drove it and still same thing. also wrapped wires in tin foil even though i thought that was stupid lol:-laf but none the less i wanna figure this out. so with all that said... the issue is {lock up switch on and converter still unlocks under power but if you cruise and use light throttle it stays locked and stacks locked when you slow down where the truck starts to choke out like a standard left in to high of a gear} please let me know what all your thoughts are. id love to figure this out. my thoughts from here after doing what ive done is lockup soliniod in transmission? or bad converter? hoping someone else has a better solution thanksOo.

 

[VolsFan]

Mine was doing the famous locking in and out of o/d, but not while it was locked out of o/d. I grounded the APPS wire to the battery and have not had any problems in several yrs, not sure if it will work for your situation, sounds like something simple though.

 

[9412v9824v]

well thanks for the info... . i am a 12 valve guy thru n thru i have one(94) along with my 24v so i need a lil more info on grounding the apps? wire? lol where do i find it and which wire is the one needing to be grounded? lol more help the better is appreciated

 

[cerberusiam]

How did you wire in the lockup switch? What wire in the harness, etc.



If you wired the lockup switch on the sense side of the circuit and the TC still unlocks, either the trans control relay is shutting down and dropping the power to the solenoids, or, your TC is TU. Once you override the TC lockup all the rest of the problems around the lock\unlock are negated and it will never unlock the solenoid electronically.

 

[9412v9824v]

i wired the lockup switch like i did the 12 valve i have... . orange with black tracer coming out of the pcm plug i spliced into (not cutting wire) and ran wire across engine bay to hole in firewall then hooked wire to toggle switch then other side of switch to ground. and what does TU mean? when you were talkin about the TC?

thanks

 

[VolsFan]

It is in the wiring harness on the drivers side near the injection pump, think it is green with a yellow stripe if memory serves correct, should say APPS, which is accelerator pedal position sensor. If you want more info, I can walk up to the shop and take a pic of it, sure not doing anything else. Cant swear it will solve ypur problem though

 

[cerberusiam]

i wired the lockup switch like i did the 12 valve i have... . orange with black tracer coming out of the pcm plug i spliced into (not cutting wire) and ran wire across engine bay to hole in firewall then hooked wire to toggle switch then other side of switch to ground. and what does TU mean? when you were talkin about the TC?

thanks

TU equals Tango Uniform, or broke. (polite temr for tits up)





Is that the same wire that is pin #7 on the trans control plug? I am thinking you need to tap the wire at the trans connection instead of the ECM. I think the PCM is not liking osmething there. Add a 33 ohm 1/2 watt resistor between the switch and ground to fool any electronic monitoring.

 

[VolsFan]

the 12 vlaves are tps, throttle position sensors, not sure why the change. Not sure how many miles on your 24, but probably gonna have to consider changing out your APPS. Then theres trucks like my dads 99 with 350k and he runs that sucker ragged with little to no maintenance and he still has his original, go figure

 

[9412v9824v]

well i went by the online procedure of how to wire it. i jumped the transmission relay in the fuse box. then ran wire from the orange w black tracer from the pcm. it runs to switch and then to ground on other side of switch. the torq switch works like it should you can feel it lock up the converter. . just when you give it hard throttle the tc unlocks. also ill take a look at the apps wire and ground it and see if it fixs it. but cont with the good input here i wanna figure this out lol

thanks

 

[9412v9824v]

also it has 190k on it

 

[9412v9824v]

also. . volsfan. . if you wanna snapa pic thatd b great. so i dont tap the rong wire and ground it out and fry my 24valve in the yard lol

 

[VolsFan]

here ya go. This is what I did, per the instructions of suncoat trans that somebody posted on here a while ago. It is a black wire with a yellow stripe. Just cut it and ran both ends to the neg terminal on the batteyr. I remember when my t/c kept locking and unlocking at around 40-45 mph. it wasnt too lonmg after I had my tranbs done, torque converter, shift kit, kevlar bands, billet input/output, the whole nine, I was ****** when it started acting up! Then I did some research on here and came up with this, hope it helps. You can see my fuel line too that shows where the harness is

 

[VolsFan]

woops, didnt post

 

[VolsFan]

this should go through

 

[9412v9824v]

ok i see what your talking about but where exactly is that harness located on the drivers side for me to splce into. thanks

 

[cerberusiam]

well i went by the online procedure of how to wire it. i jumped the transmission relay in the fuse box.

Thats the wrong way to do it and is likely causing the PCM to freak out.



Pull the jumper off the relay. Thats a good way to melt the harness and start the truck on fire. Totally not needed.



The solenoids for lockup and OD are powered all the time thru the trans relay. You want to leave that control intact and not mess with it. Lockup and OD are activated by the PCM grounding the circuit to the solenoids. Thats the circuit you want to tap into.



Pull the plug on the transmission control harness on the drivers side, the round one pointing up. Find pin #7 and that should be the lockup sense wire. scotchlock onto it and run the wire to the switch. From the other side of the switch run to a 33 ohm 1/2 watt resistor then to ground.



When you activate the switch the lockup circuit will always be grounded and it will apply given the TC is good. That way you get around all the PCM controls and other issues that can cause problems. The resistor will not let the PCM see a ground fault and the trans control relay will not trip on a direct ground like it probably is.

 

[9412v9824v]

ok... . i see that way of doing it... the way i did it is in direct following of the instructions on the tst website which is where i got the directions for my 12valve... here is the link so you can check it out... http://www.tstproducts.com/Torque Converter Lockup Switch.pdf

 

[9412v9824v]

hey cerb... did you look at tst way of wiring the torq locker?? but neways also vols. . ima try the black with yellow tracer to the neg this morning... but where is that harness located on the drivers side? on the firewall?? hopefully thatll fix it... if not. . more sudjestions are loved thanks

 

[cerberusiam]

hey cerb... did you look at tst way of wiring the torq locker?? but neways also vols. . ima try the black with yellow tracer to the neg this morning... but where is that harness located on the drivers side? on the firewall?? hopefully thatll fix it... if not. . more sudjestions are loved thanks

That harness is on the PCM behind the air cleaner. Considering the loaction, I think the trans harness is easier to get to. I do not like jumping the relay as it is not needed and dangerous. Using the resistor is the correct way to wire in the over ride.

 

[9412v9824v]

ok ya i understand where your coming from i just thought id show you how i did do it. . according to tst and yes i tapd into the harness behind air cleaner. at pcm. i have a afe intake so there is plenty of room to get to it unlike with stock filter setup. but none the less i will try rewiring the switch if the groundin of the black with yellow tracer doesnt work. but just cleaning the battery terminals helped it alot. i unhooked and rehooked negs after cleaning and the problem has almost gone away... . not completely yet thus why i will try grounded the black with yello tracer coming off apps. if that doesnt fix it completely ill try rewiring the switch. i would of already grounded the apps wire but wife took it to work lol she likes it better then the 12 valve cuz it dont roll coal thru every intersection hahahaha