Torque Converter Unlocking - Wheel Speed Sensors & ABS

Mark Kovalsky · May 24, 2013

Layson said:
Just the little deal below where the shift linkage hooks up. Where the main plug for the tranny plugs in.

The main plug is on the passenger's side of the trans.

Layson said:
It is the neutral safety switch. I think that is what they call it.

It's called the Transmission Range Sensor (TRS,) or Manual Lever Position Sensor (MLPS,) or Neutral Safety Switch (NSS.) It doesn't have anything to do with lockup.

Layson · May 24, 2013

Mark, thanks for the help. I totally forgot that the main plug was on the passenger side. So I went and I pulled it out and check this out...

I must have a slight leak either on one of the cooler lines or the dipstick. Nothing that is enough to produce a drip. But it must have been filling the male end of the plug up with oil. There isn't any place for it to go in the plug but just fill it up. So I blew it all out with air and I am going to let it sit overnight and then fill it with dielectric grease! I am thinking this has to be it....

moose99psd · May 24, 2013

And as far as I know none of the tail light issues have any bearing on superdutys, it was an obs issue that was fixed.

from my butt

Layson · May 24, 2013

I am thinking it has to be that plug. The male end was full of oil and it was dripping out of the female end after I unplugged it! Hopefully that is it!

Layson · May 26, 2013

Well it wasn't it unfortunately. Pulled the PCM and cleaned out the contacts real good. Then I stuck my backup PCM in and it still did it.

Now the weird thing is the torque converter will unlock and lock up several times once the truck is warmed up, then it won't do it again. Then I turn off the truck and then it starts doing it all over again.

For some reason the codes for the ABS module and right and left sensors are not clearing. They come back after I clear the codes. Previously during troubleshooting I unhooked them and then pulled the fuse for the ABS module. Everything is back hooked up but still seeing codes?

Whitezotti · Jan 28, 2014

Have you figured out the problem yet?

I to have the same problem with my tc unlocking and having trouble lock back up. I also have a BTS tranny. But mine is on a 6.0. I only have this problem above 45 mph also.

Thumpgrinder · Jan 28, 2014

I had problems with my TC this weekend on a trip pulling a trailer. After reading online I noticed someone say that he had the issue when hooking up trailer lights. I disconnected my trailer lights and the problem with the TC went away. Something about a problem with a bulb in the taillight. Anyone know if there is a fix for that?

Layson · Jan 28, 2014

I dropped the pan, changed the filter, and filled it back up. Then I figured I would overfill it by a little bit since they recommend that. It never did it again. So I am not positive. Only thing I can think of is maybe my dipstick is a little longer than normal and so I was actually low on fluid when I thought it was full???

Whitezotti · Jan 28, 2014

Did you ever change the tune on your truck? I thought maybe it could be it. But I have hit the trailer brake button to disable it and it helped but still does it. It takes a good 5 seconds to lock back up after.

Whitezotti · Jan 28, 2014

I don't have this problem on my 7.3 and it's a BTS tranny to

Layson · Jan 30, 2014

Whitezotti said:
Did you ever change the tune on your truck? I thought maybe it could be it. But I have hit the trailer brake button to disable it and it helped but still does it. It takes a good 5 seconds to lock back up after.

Nope, never did!

mandkole · Feb 22, 2015

Steven, did you figure this out? I've just been seeing some weird behavior with this also. Top gear, light grade , 45-50% throttle. If the converter lock switch is on it stays locked.

Layson · Feb 24, 2015

Had to replace my torque converter. Get AE or something else that can see TC lockup and TC modulated.

golfer · Feb 24, 2015

mandkole said:
Steven, did you figure this out? I've just been seeing some weird behavior with this also. Top gear, light grade , 45-50% throttle. If the converter lock switch is on it stays locked.

ask your tuner.

I've purposely done this on large(r) injector trucks with large(r) single turbos to aid spool and minimize smoke.

mandkole · Feb 27, 2015

Agreed, I thought about tuning and it was just in a throttle position where it would 'hunt'.

A few months ago the trans was acting weird and dying when put into reverse on cold fluid temp. Acted like there was a pump cross leak and my local trans guy/buddy was certain of the same thing. Now, it is no longer dying, but now the converter will unlock more easily. I can still turn on the converter lock switch and override, the converter stays locked. Perhaps its a solenoid issue or electrical--

There will be more to review on this, but I need to be sure Im not chasing my tail first.

Layson · Feb 27, 2015

Just got to watch the lockup on AE and watch slippage.

It is interesting that Dave chimed in here since I am running Swamps tuning...LOL I wonder if it was acting weird due to the tuning in combination of the TC going out.

mandkole · Feb 27, 2015

Ive still got to drive it more and maybe I'll need to make a lap with your AE if that works for you. If I switch the TC to lock, its locked up good. Im still trying to understand why it suddenly shifts correctly to reverse when cold. Before you could kill it going into reverse or drive when the fluid was below 70F or so.

The grandpa truck has worked so good and Im so used to not working on it...lol