Greetings,

I have a '99 24v CTD 3500 with Auto Trans. It has started "Searching" between 2nd and 3rd or 3rd and TC lock (not sure). I don't know much about these transmissions, but know that it's a known problem.

Funny thing is: about 6 months ago, a friend sent me this link from ebay for a part that a company manufactures for this exact problem. It's supposed to bypass this dilema and solve this exact problem. I CAN'T FIND THAT VENDOR WHO MAKES THIS HARNESS!!!.

If anybody has an idea what I can do for this problem, please respond. I have my camper loaded for family vacation / trout fishing trip, and I need to get it fixed before saturday...

Thanks in advance for any help.

 

At which speed does it do that?
Does it do it when you have the OD off or not?
How many rpm difference on flat ground? (at which speed)

If it's a noise problem on the APPS signal lots of people had good success with a DTT noise filter. Others went to radio shack or the like and placed a 33-100 mju Fahrad capacitor (must resist up to 100 V)between the APPS cable and ground.
(Pin 23 on the pcm connector 1 -the black plug fight behind the air filter- an 18gauge cable orange with a dark blue tracer and pin31 14gauge black with tan tracer)
The smaller the resistor the better , if it's too big the kickdown from OD lock will be delaied.

Did you try to reset the APPS first?

HTH
AlpineRAM

 

AlpineRam,

The speed that I travel when the "Searching" begins is from 32-36mph with the OD selected "OFF" just running around town. (I'll check to see if it does it when OD is normal) I did not notice in at highway speeds.

I did not notice it when the truck was empty, I have a 12' Fleetwood Caribou cabover camper (close to 4k weight, airbags installed) on back now, but I drive carefully and the truck hardly notices it back there.

The RPM Difference is about 400 rpm or so, I'll double check on my way to work. The problem is only noticed on Flat ground usually, but sometimes happens on slight inclines - I'll double check on that also and reply again

- What is a "Noise Problem on the APPS"

- what is an APPS signal?

- How do I reset the APPS?

- Is there another recent thread on the detailed procedures for doing this, your post sounds like you've done this before?

- Is it easy?

- Has anybody heard of any harness that bypasses / tricks some sensor and solves this problem? Heck, maybe it was that filter that you are introducing me to... I'm still looking for the one that my friend send me months ago, from ebay.

Thank you for your reply, I'll get back to you this evening...

Pete

 

Alpine,

- Only happens with the OD selected "OFF".
- Fluctuates from 1400 - 1600 RPM's when "Searching".
- Seems to only do it on level pavement.

Boy, I'm frustrated... I hope there is some life left on my tranny!

Is this a common problem with the CTD AT's?

McGyver

 

I can tackle this one.

The APPS reset procedure is in the Tech Facts link at the top of every page.

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

Couple of additions/clarifications:
#3, leave key "on" for about 15 minutes or so to make sure everything is cleared.
(perfect length of time to consume two barley pops, if you are so inclined. )
#4, 30 minutes is the minimum, I'd go for an hour, again to make sure everything is cleared.


phox

 

Well, this sounds perfectly like a light case of signal noise. If it happens only on level ground with OD off it's just that you have to give so little go pedal that the tranny computer can't decide if you want to coast or pull. I think you should try the APPS reset first, then the capacitor. Take a small one, like 33mjuF (should be a 15c part @ Radio Shack or any TV repair shop)

EDIT: Clean your battery posts, and the big fuse in the PDC (fuse box under the hood) and these connectors while the batteries are disconnected for the APPS reset

As long as the tranny didn't do it for very long there's no cause for alarm.

HTH

AlpineRAM

 

Thanks for the response, it's a big help.

On the way home from the base today here is what it did:

OD selected "ON" normal position, Truck surged like before at 48-50 mph from 1400-1600rpm's. Just like when the OD is selected "off" and I"m going 30 mph.

I'll read the reply and thread above and follow it. I'll see what it does for me.

Is this indicative of the same thing that you reply'd to? (when I'm going 50mph also?

Thanks again,

Pete

 

Yep, same thing. You feather the go pedal and the truck doesn't know whether you want it to pull lightly (lock converter) or coast (open converter).
Since you don't have load on it the wear and tear on the lockup clutch isn't too high. So if you do something against it soon there shouldn't be a problem.

AlpineRAM

 

Are you sure it's not the TC lockup solonoid? There have been several posts about it in the past where the TC will continually lock and unlock. My 98.5 used to do it on occasion and there is a TSB out for it.

 

I'll go through the APPS reset steps tonight, then I'll look into the noise reduction like it was suggested. I may need to ask some questions about where to put that gadget.

Where is the TCC solonoid located?

Thanks for your help!

Pete

 

The TCC solenoid is controlled by the PCM, based on the following inputs: Speed, gear and APPS (throttle position)
If the PCM (powertrain control module) can't decide what you want eg- you cruise and have the speed you desire and leave off the go pedal a bit it will think you want to coast and cut the grounding of the TCC solenoid- the lockup clutch will release. You step on it a bit more to recover the lost speed and the PCM sees moderate acceleration and will ground the solenoid- lockup applied- you see that you have the desired speed, let off etc etc.
The TSB will overwrite the PCM programming to accept less go pedal as still "go".
Noise on the APPS signal will look like the driver pumping the pedal to the PCM and therefore unlock-lock-unlock etc. If you clean the signal a bit you'll get the same result.

Just my 2c

AlpineRAM

 

WHat is a TSB? Is it a safety bulletin?

Thanks for the input. I'm heade out to the garage to "Dump" and "Reload" stuff, I'l clean the posts and big fuse in the process. (and reset the TCC)

Thanks,

Pete

 

TSB = Technical Service Bulletin. The company issues them to mechanics. Some of the TSBs are "secret."

 

Thanks for all of your input and information.

I did what was suggested to me (Reset TCC and clean the post's) and all is well now.

I just returned from a week camping trip with my kids, and had no problem with the truck pulling the camper and the boat.

Thanks again for such a good forum for those of us that don't want to get taken at the dealer...

Very Respectfully,

Pete

 

At the advice of supertorquer I called ATS in Colorado. Joel there walked me through the process of re-wiring the APPS wire directly to the PCM, and adding a direct ground. My truck is cured of "Searching" entirely and shift's WAY better now.

I wanted to take the time to tell all who wrote me and gave me ideas and suggestions, THANKS. It's a relief that I can fix my own truck, FOR FREE!

If anybody has a 46/47re on a 1998 and UP... If you're trans is not holding the gear, pm me and I'll help you with the easy fix. It takes about an hour, but is well worth it.

Thanks again, and cheers!