4LO is Dead?

[4thGen4.7]

Such an unusual case I couldn't find anything in search. A few months ago a shop put in a a tcase from another v8, lightly used.

They just did some work on the A/C and when they put the dash back together the 4LO beeps and flashes... they're blaming it on the tcase... I used 4LO after they installed it tho and it worked fine.

Thoughts?

 

[4RunnerAquasport]

I've heard of the knob on the dash getting stripped and not engaging the switch fully. Could be an electrical connection not fully seated on the switch, or the dreaded bad 4Lo servo on the Tcase itself.
Kind of broad suggestions I know, but start with the stripped knob and eliminate that first. It has tripped up a few people before.
Hope its a simple fix and good luck!
Edit: it could just be that when they reinstalled the dash, the knob was installed wrong with the 4Lo switch engaged and the knob in the wrong position. If the vehicle is not stopped and in neutral, this would cause the warning lights.

 

[montijo505]

I've heard of the knob on the dash getting stripped and not engaging the switch fully. Could be an electrical connection not fully seated on the switch, or the dreaded bad 4Lo servo on the Tcase itself.
Kind of broad suggestions I know, but start with the stripped knob and eliminate that first. It has tripped up a few people before.
Hope its a simple fix and good luck!
Edit: it could just be that when they reinstalled the dash, the knob was installed wrong with the 4Lo switch engaged and the knob in the wrong position. If the vehicle is not stopped and in neutral, this would cause the warning lights.

Yeah try taking it apart before anything else. Plenty of people that thought t case was dead when in reality an audio installer forgot to plug the switch in when putting the dash together.


Sent from my iPhone using Tapatalk

 

[4thGen4.7]

I've heard of the knob on the dash getting stripped and not engaging the switch fully. Could be an electrical connection not fully seated on the switch, or the dreaded bad 4Lo servo on the Tcase itself.
Kind of broad suggestions I know, but start with the stripped knob and eliminate that first. It has tripped up a few people before.
Hope its a simple fix and good luck!
Edit: it could just be that when they reinstalled the dash, the knob was installed wrong with the 4Lo switch engaged and the knob in the wrong position. If the vehicle is not stopped and in neutral, this would cause the warning lights.

Yeah try taking it apart before anything else. Plenty of people that thought t case was dead when in reality an audio installer forgot to plug the switch in when putting the dash together.


Sent from my iPhone using Tapatalk

I appreciate the suggestions guys, I brought it up with the tech and it sounds like he did a good bit of due diligence to try and find the issue. Apparently after the module under the dash was plugged back in the computer did a self test that showed the problem is in the actuator inside the tcase, basically saying it doesn't know whether it is in hi or lo. When they installed the tcase the computer hadn't done the self test so the issue never came up. So I either have to bypass (temporary?), or switch out actuator or tcase entirely.

 

[4RunnerAquasport]

I appreciate the suggestions guys, I brought it up with the tech and it sounds like he did a good bit of due diligence to try and find the issue. Apparently after the module under the dash was plugged back in the computer did a self test that showed the problem is in the actuator inside the tcase, basically saying it doesn't know whether it is in hi or lo. When they installed the tcase the computer hadn't done the self test so the issue never came up. So I either have to bypass (temporary?), or switch out actuator or tcase entirely.

Aww crap, yea that is the Achille's heel of the electronic activation on these trucks.
Hope you can get it fixed for a reasonable price. There are several threads dealing with this problem.
I've got a manual tcase I'm gonna install in mine soon. Not waiting until it quits working.

 

[bowhunter53]

I just purchased a 2006 sport with 85k miles and I can guarantee it was NEVER in 4LO. Crawl under and tap the actuator (black box attached to the t case) with a rubber mallet and keep working the switch in and out of 4LO. Mine freed up after about 4 or 5 taps and is good as new. Keep working the switch daily for a week to be sure it continues to operate correctly.