Occasionally I get the 4LO and Diff-Lock yellow lights on when I start the LC200. (1 Viewer)

[Fisher23]

Occasionally I get the 4LO and Diff-Lock yellow lights on when I start the LC200.

Sometime if I turn off the LC200 and re-start it they go away.
Other times I need to drive about 5 miles and then turn the LC00 on and off and they go away.

I checked and when these lights are on it will not switch into 4LO and will not lock the diff.

I get this after just normal city driving, parking overnight, then they show up in the morning.

More so on cooler morning under 70 degrees, but some times when it's 75+.

Anyone had this? or know what causes it?

I'm lost on this one.

This is 2016 with about 65k on it now.
Normal maintenance all done, and 75W in the diff.

 

[Markuson]

Occasionally I get the 4LO and Diff-Lock yellow lights on when I start the LC200.

Sometime if I turn off the LC200 and re-start it they go away.
Other times I need to drive about 5 miles and then turn the LC00 on and off and they go away.

I checked and when these lights are on it will not switch into 4LO and will not lock the diff.

I get this after just normal city driving, parking overnight, then they show up in the morning.

More so on cooler morning under 70 degrees, but some times when it's 75+.

Anyone had this? or know what causes it?

I'm lost on this one.

This is 2016 with about 65k on it now.
Normal maintenance all done, and 75W in the diff.

Very good chance it’s something as simple as your fuel evap canister throwing codes. Get an inexpensive OBDii reader and see. If evaporative related, clear the codes and roll on. Lots of fuel related codes can be thrown that tend to show up after the cooled temps of night time.

 

[radman]

You get them at the same time?

Like @Markuson said, 4lo alone can be as simple as a loose gas cap.

I get the flashing center lock, but mainly when it's cold outside. Hasn't happened this spring/summer yet.

Flashing Center Diff Lock Light 200 Series

...Unless there's a switch or sensor in the transfer case that I'm not aware of, it has to be associated with the microswitch, or the solder joints shown in the video above... I’m not sure if the micro switch is the only sensor, but I generally agree there has to be a finite number of...

forum.ih8mud.com

 

[Ratchey]

I found that a low battery can cause these lights to come on.

 

[Fisher23]

Very good chance it’s something as simple as your fuel evap canister throwing codes. Get an inexpensive OBDii reader and see. If evaporative related, clear the codes and roll on. Lots of fuel related codes can be thrown that tend to show up after the cooled temps of night time.

Thanks, I read the codes and it was just evap codes, so I thought that was a separate issue.

I post a new tread on my evap issue.

 

[Markuson]

Thanks, I read the codes and it was just evap codes, so I thought that was a separate issue.

I post a new tread on my evap issue.

As insane and unrelated as it sounds (and is), Evap codes set off all kinds of lights on the dash, including 4Lo...and keep you from shifting into 4LO (a ridiculous disabling Toyota should never have connect to such a benign thing).

So... If you only had evap codes (there are usually 5 codes thrown...all five for related to evap), clear them via the OBDII. You can actually do this clearing (reset) while the truck is running. After clearing, if the lights go away... it likely means you will have to regularly clear evap codes. It’s annoying as heck...but not causing damage.

 

[Fisher23]

Thanks !

 

[stonepa]

A loose or corroded ground strap can do this.

 

[Fisher23]

How do I fix this?

I get a P0441 Evap code for purge control valve sticking.

This is what is going on:
When I stop and turn off the vehicle to get gas or to park over night I think the purge valve should release the pressure in the fuel tank BUT that is not happening.

It is not releasing the pressure in the fuel tank when I stop and turn off the vehicle.

When I stop to get gas and open the fuel cap you can hear the pressure release though the cap area, so the pressure is not being released like it should.
If I open the cap in the morning after parking overnight before starting the vehicle you can hear the pressure escape.

If I open the cap in the morning before driving, especial when cold I do not get the error.

 

[Markuson]

How do I fix this?

I get a P0441 Evap code for purge control valve sticking.

This is what is going on:
When I stop and turn off the vehicle to get gas or to park over night I think the purge valve should release the pressure in the fuel tank BUT that is not happening.

It is not releasing the pressure in the fuel tank when I stop and turn off the vehicle.

When I stop to get gas and open the fuel cap you can hear the pressure release though the cap area, so the pressure is not being released like it should.
If I open the cap in the morning after parking overnight before starting the vehicle you can hear the pressure escape.

If I open the cap in the morning before driving, especial when cold I do not get the error.

FWIW, I have only ever seen the pressure release thing happen once on my truck..but have seen the evap codes many many MAAAANY times. So all that to say... it is not necessarily always goi mg to show this pressure buildup in that way. My most often does it in the morning, like yours, or after sitting for several days. I do think it’s pressure related, but the big burp is a one-time-only on mime