Center Diff Lock & ATRAC VSC issues

[TexasCrane]

Hi all,
I'm hoping you all can help me troubleshoot a problem that cropped up this past weekend while out at Big Bend.

First of all, engaging the center diff lock when in 4L works just fine. The VSC OFF light comes on and everything functions like it should. Everything turns on and off correctly. If I engage the diff lock in 4L and then switch the transfer case into 4H, everything continues to function correctly.

However, if the center diff is open and I engage it while in 4H, the VSC OFF and the VSC TRAC lights come on. If I then disengage the lock, the VSC OFF and VSC TRAC lights remain on. The only way to get them to turn off is to turn off the ignition and restart the car.

I don't have any of the P/D/R/N lights out and I haven't replaced any of the dash lights with LEDs (which seems to have led to the VSC TRAC and VSC OFF light combo for some people).

Any ideas would be appreciated. Thanks.

Here are a few pics from this weekend:

 

[Mike6158]

I can't help with the VSC issue but I like the shot of Santa Elena Canyon. Was that from Old Maverick Road or Terlingua Abaja?

 

[TexasCrane]

Thanks. That was from terlingua abaja.

 

[silverbullitt]

Sometimes after you disengage & put the truck in normal 4 hi. put the in reverse & back up a few feet & the light will go out.

 

[revoked]

Bump, same issue. Anyone else?

 

[sacmaster]

Mine was doing this the other week. Didn't do it this weekend though. I think it's just a sticky solenoid or something.

 

[revoked]

Thanks sacmaster, guess I will try to engage it more often in hopes is resolves itself.

 

[screendoor]

I have the same issue, when I turn off the Center diff lock, the VSC OFF and VSC TRAC lights stay light until I restart.

 

[revoked]

Just gave it a try in the parking lot at work, working correctly. Guess it just needs more exercise.

 

[SS100]

Will backing up a few feet turn the lights off (disengage the center diff lock)?

Great photos of BB.

 

[revoked]

SS1000, I didn't have a problem disengaging, the VSC TRAC light stayed on until I restarted the car.

 

[RoosterChaser]

SS1000, I didn't have a problem disengaging, the VSC TRAC light stayed on until I restarted the car.

Did you ever resolve this issue? Having the same problem with a garage queen that likely never had the CDL locked. Lack of use seems to be the cause from other members here as well.

 

[2001LC]

Very often, if you just keep turning on for short drive than off. Repeating often over time. It will free itself.

 

[RoosterChaser]

Very often, if you just keep turning on for short drive than off. Repeating often over time. It will free itself.

You are referring to the switch/solenoid for the VSC TRAC light or the CDL?

 

[2001LC]

I'm referencing the CDL switch. Turn it on often. You'll hear a relay in RH foot well click. VSC TRAC light come on.

Make sure it's actually delivery power evenly to all wheel when CDL on. By simply reversing vehicle, while turning steering wheel to lock (all the way right or left). Tires will skip when CDL is engaged. VSC TRAC lights on (is ABS off).

Make sure CDL not engaged. With same reversing & turning to lock.

 

[RoosterChaser]

I'm referencing the CDL switch. Turn it on often. You'll hear a relay in RN foot well click. VSC TRAC come on.

Make sure it's actually delivery power evenly to all wheel when CDL on. By simply reversing vehicle, while turning steering wheel to lock (all the way right or left). Tires will skip when CDL engaged. VSC TRAC lights on (is ABS off).

Make sure CDL not engaged. With same reversing & turning to lock.

Yeah that’s not my issue. CDL locks and unlocks perfectly and the CDL light works too. And I think you have it backwards on the lights. VSC OFF is supposed to go on and off with the CDL. VSC TRAC is a sign of some issue, according to the owners manual anyway. Either way, they both come on when locking the CDL and do not go off after unlocking it. They will go off after restarting the truck though. Lots of guys having this issue and most are saying to ignore it. Just want to be sure of what I’m getting into.

 

[retiredguest]

Yeah that’s not my issue. CDL locks and unlocks perfectly and the CDL light works too. And I think you have it backwards on the lights. VSC OFF is supposed to go on and off with the CDL. VSC TRAC is a sign of some issue, according to the owners manual anyway. Either way, they both come on when locking the CDL and do not go off after unlocking it. They will go off after restarting the truck though. Lots of guys having this issue and most are saying to ignore it. Just want to be sure of what I’m getting into.

I had this exact same problem today, only after getting back on the paved road, I darn near lost all my brake pedal half way down the mountain grade. No buzzer, warning lights. Everything back to normal once I reached level ground.

 

[SS100]

Did you ever resolve this issue? Having the same problem with a garage queen that likely never had the CDL locked. Lack of use seems to be the cause from other members here as well.

No haven't resolved it. It happens sometimes, not every time I engage the CDL, so it's hard to diagnose and as it has not adversely affected the truck's performance I honestly forget about it lol! (Due to current situation, I haven't been able to get out like I normally do, so last time I used the CDL was in January). When it happens the lights will turn off after dis-engaging CDL if I shut the engine off and then restart it. If you find the cause/solution, please do post. I'll do the same

 

[SS100]

I had this exact same problem today, only after getting back on the paved road, I darn near lost all my brake pedal half way down the mountain grade. No buzzer, warning lights. Everything back to normal once I reached level ground.

I haven't had any braking issues (or other) when the lights stay on after dis-engaging the CDL. Haven't tested it, but I'd figure VSC is off so, can probably spin the wheels if I wanted though.

 

[RoosterChaser]

No haven't resolved it. It happens sometimes, not every time I engage the CDL, so it's hard to diagnose and as it has not adversely affected the truck's performance I honestly forget about it lol! (Due to current situation, I haven't been able to get out like I normally do, so last time I used the CDL was in January). When it happens the lights will turn off after dis-engaging CDL if I shut the engine off and then restart it. If you find the cause/solution, please do post. I'll do the same

Sounds good. Seems like a lot of guys are having the issue and ignoring it as it can be eliminated after a restart. I’d still like to figure out the cause if only to satisfy my curiosity. I’ll keep ya posted.