Flashing Center Diff Lock Light 200 Series (4 Viewers)

[2008Sequoia]

Sorry for the upside down writing. Lol. I drew the lines and made the notes, then had to spin them to have it make sense in relation to how I was looking at the actuator on the table and how it’s sitting in the truck. So, if I’m reading this right, the rod is actually pushed all the way in. I’m going to try pulling it out, re-aligning the clock correctly in the proper orientation and see what happens. The longer I’m thinking of this, the more I’m seeing how the gear, as it rotates counterclockwise would be engaging the pin into the transfer case - thus engaging the leaver…that my theory. Sorry for the spam posts. I’m just having a mild case of OCD here trying to make sense of this.

 

[TeCKis300]

Sorry for the upside down writing. Lol. I drew the lines and made the notes, then had to spin them to have it make sense in relation to how I was looking at the actuator on the table and how it’s sitting in the truck. So, if I’m reading this right, the rod is actually pushed all the way in. I’m going to try pulling it out, re-aligning the clock correctly in the proper orientation and see what happens. The longer I’m thinking of this, the more I’m seeing how the gear, as it rotates counterclockwise would be engaging the pin into the transfer case - thus engaging the leaver…that my theory. Sorry for the spam posts. I’m just having a mild case of OCD here trying to make sense of this.

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This grease stain on the rod and gear may be matchmarks that can help confirm or align the gears?

 

[2008Sequoia]

Great idea! I hadn’t thought of that! Thanks for adding another sanity check for me to look at!

 

[2008Sequoia]

SUCCESS!!! Mischief managed!!! I fixed it!!! Thank God! After three days, much frustration and two sleep less nights. I’ve fixed my 4x4.
YouTube video to follow…
What a PITA.

 

[2008Sequoia]

As promised, here’s the YouTube link to how I fixed the Flashing 4-Hi/4-Lo & Center Differential Light fault in my 2008 Sequoia.

***Apologies for the distracting/crappy audio track - sounded less obnoxious on my iPhone when editing - after I uploaded it, and there’d already been a bunch of views I realized it was a little too hot. :/ ***

 

[Bunga]

Great debug! Very clear and thoughtfully deciphered.

 

[2008Sequoia]

Great debug! Very clear and thoughtfully deciphered.

Thank you! That was the goal - to try and provide others with the knowledge of fixing these rig themselves.

 

[ToyotaofWar85]

I bought my 2015 LC about a year ago and the flashing diff light has come on 4 times now (once every 3 or so months) and turns off after I drive it and shut it off and turn it back on. I’ll have to check out the video posted above. It’s not a huge deal, just annoying to look at every now and then.

 

[Catskills]

This happened to me for the first time yesterday. First day the truck was left outside instead of in garage and it was a cold, damp night. Drove it for twenty minutes, light still flashing, and cruise would not work. But then, just as you guys reported, turned truck off and on and light was gone.

 

[ThRiLlGmYr]

So, my Center Diff light has been blinking almost every morning this week. It has been very cold over night. But one morning I accidently hit the start button without my foot on the brake so it was in kind of an accessory mode (I guess) and I put my foot on the brake and the car started with no blinking center diff light. The next day I started as normal and the center diff light was blinking. Today I pushed the button with foot off the brake and then pushed it a second time with my foot on the brake and it started with no center diff light. I can't be sure if the center diff would have come on if I started it regularly but it may be worth trying. My center diff light always goes off after I warm up the truck and restart it but if I can avoid that at the first start up it is worth it. Unless there is something bad about starting that way.

Third time was not the charm. I did my two start method and it failed today. Center diff light started blinking even before I started the engine. Back to the drawing board.

 

[Mineral]

Fwiw, the light would come on intermittently for me. Usually on the morning when cold. I’d drive a quarter mile, shut off the vehicle, and it’d go away.

Recently, my dash lit up like a Christmas tree, starting w center lock and then brake light and vsc and other lights would flicker. Eventually, an audible ding and nearly all the dash lights would come on.

I took the 200 to Lefty’s, a local electrical specialist in Phoenix. Within a couple hours Ralph diagnosed the rear abs stub harness had a broken wire. Couple days later, the new harness came (left and right sides are both included). Ralph installed them and issue went away.

My theory is that the harness wire that eventually broke was loose for awhile, causing the center lock light to randomly turn on.

Or, maybe there is correlation but no causation. Electrical is voodoo to me.

 

[isthatalexus]

@2008Sequoia great video and descriptions, and thank you for sharing the insights. I think it's appropriate to cross-post from a thread in which I documented my experience with the t-case actuator. Many bits will be familiar (although I was not ambitious enough to do video) but I focused a bit more on the sub-micro-switch, which I believe was the issue in my case. Transfer Case Tuneup and Fix - https://forum.ih8mud.com/threads/transfer-case-tuneup-and-fix.1215394/post-14503750

In the end, I think the CDL/4L blink, no-engage/no-disengage, and C1340 related issues are caused by one or a combination of:

• actuator housing breather hose disconnect results in motor and/or contact fouling
• microswitch (in either side of the house) damaged externally (plastic arm) or internally (copper contacts)
• less frequently, CDL button or 4LO knob contact integrity issues
• deep-sixed 4WD computer assembly (in footwell) due to water ingress or some more sublte electronics failure

A hypothesis regarding the cold-start phenomenon discussed in this thread: I found that the hair-thin copper contacts inside the micro-switch were 'out of shape' just enough to disallow closing the circuit. Could be caused by atrophy from use or sub-optimal manufacturing tolerance, or something else. In cold temps, the thin copper fins could be contracting further, compounding the issue.

I have gone deep into the sub-micro-switch rabbit hole, but was never able to find an OTS product that looked the same. Maybe I'll continue that search one day and buy a pound of them.

 

[2008Sequoia]

@2008Sequoia great video and descriptions, and thank you for sharing the insights. I think it's appropriate to cross-post from a thread in which I documented my experience with the t-case actuator. Many bits will be familiar (although I was not ambitious enough to do video) but I focused a bit more on the sub-micro-switch, which I believe was the issue in my case. Transfer Case Tuneup and Fix - https://forum.ih8mud.com/threads/transfer-case-tuneup-and-fix.1215394/post-14503750

In the end, I think the CDL/4L blink, no-engage/no-disengage, and C1340 related issues are caused by one or a combination of:

• actuator housing breather hose disconnect results in motor and/or contact fouling
• microswitch (in either side of the house) damaged externally (plastic arm) or internally (copper contacts)
• less frequently, CDL button or 4LO knob contact integrity issues
• deep-sixed 4WD computer assembly (in footwell) due to water ingress or some more sublte electronics failure

A hypothesis regarding the cold-start phenomenon discussed in this thread: I found that the hair-thin copper contacts inside the micro-switch were 'out of shape' just enough to disallow closing the circuit. Could be caused by atrophy from use or sub-optimal manufacturing tolerance, or something else. In cold temps, the thin copper fins could be contracting further, compounding the issue.

I have gone deep into the sub-micro-switch rabbit hole, but was never able to find an OTS product that looked the same. Maybe I'll continue that search one day and buy a pound of them.

Thank you for the information - all good stuff to build the general knowledge base on this issue that seems to be spread across many models and years/generations of Toyotas. The micro switch and motors were dead ends for me. I even looked at trying to find a motor that was of similar form factor and voltage/rating that might be able to be Frankensteined into place and wasn’t confident enough to want to try it - I’m sure it’s possible though. I found many options just didn’t want to waste time going down that rabbit hole - though perhaps if I did, I could offer more insights as to a more affordable solution to this issue!

 

[LX Cruiser]

Fwiw, the light would come on intermittently for me. Usually on the morning when cold. I’d drive a quarter mile, shut off the vehicle, and it’d go away.

Recently, my dash lit up like a Christmas tree, starting w center lock and then brake light and vsc and other lights would flicker. Eventually, an audible ding and nearly all the dash lights would come on.

I took the 200 to Lefty’s, a local electrical specialist in Phoenix. Within a couple hours Ralph diagnosed the rear abs stub harness had a broken wire. Couple days later, the new harness came (left and right sides are both included). Ralph installed them and issue went away.

My theory is that the harness wire that eventually broke was loose for awhile, causing the center lock light to randomly turn on.

Or, maybe there is correlation but no causation. Electrical is voodoo to me.

My CDL light would come on and flash with the “check VSC system” message in cold weather, too. And if I tried to engage it, same thing. Engaging 4Lo would cause it to just flash as well. I swapped fresh 75w oil into the transfer case and started turning on the CDL and engaging 4Lo after a long drive with the truck fully warmed up. For the first couple days, the light would just flash on the dash like before. I would power cycle the truck, do it again, dash would light up again, and then try again the next day.

After four days of doing this, both decided to engage and disengage smoothly and properly. I do it weekly now, and even though it’s colder out now than when it started happening a couple months ago, it has been fine ever since.

Fresh gear oil and exercising the actuators fixed it for me. I don’t think they had ever been turned on in 150k miles. The TC oil was dark amber. Probably original.

 

[2008Sequoia]

My CDL light would come on and flash with the “check VSC system” message in cold weather, too. And if I tried to engage it, same thing. Engaging 4Lo would cause it to just flash as well. I swapped fresh 75w oil into the transfer case and started turning on the CDL and engaging 4Lo after a long drive with the truck fully warmed up. For the first couple days, the light would just flash on the dash like before. I would power cycle the truck, do it again, dash would light up again, and then try again the next day.

After four days of doing this, both decided to engage and disengage smoothly and properly. I do it weekly now, and even though it’s colder out now than when it started happening a couple months ago, it has been fine ever since.

Fresh gear oil and exercising the actuators fixed it for me. I don’t think they had ever been turned on in 150k miles. The TC oil was dark amber. Probably original.

Dodged a bullet so far. The TC oil doesn’t have much bearing on the actuators - if at all. But crappy fluid isn’t going to do ya any favors that’s for sure! Check your breather hose! You probably got the contacts to break loose enough to make the circuit connection they needed.
Unorthodox fix but always good to have other people’s experiences in what’s worked to resolve this!

 

[LX Cruiser]

Dodged a bullet so far. The TC oil doesn’t have much bearing on the actuators - if at all. But crappy fluid isn’t going to do ya any favors that’s for sure! Check your breather hose! You probably got the contacts to break loose enough to make the circuit connection they needed.
Unorthodox fix but always good to have other people’s experiences in what’s worked to resolve this!

Transfer case breather hose? I’ll have to read the rest of the thread.

I don’t think the oil magically fixed it. It was well past time to change it. I think it was due more to the repeated, daily exercising after warming up. Reading around different forums, it is a pretty common fix for people who buy an older LC, Tundra, Sequoia, etc where 4Hi, 4Lo, or the CDL were never used.

 

[2008Sequoia]

Transfer case breather hose? I’ll have to read the rest of the thread.

I don’t think the oil magically fixed it. It was well past time to change it. I think it was due more to the repeated, daily exercising after warming up. Reading around different forums, it is a pretty common fix for people who buy an older LC, Tundra, Sequoia, etc where 4Hi, 4Lo, or the CDL were never used.

Yeah, there’s a little hose on top of the unit that comes loose/fails/breaks - God-only-knows-what that can allow moisture in.

Check out my video if you want - pardon the crappy audio soundtrack ( my first stab at a YouTube channel post) - you’ll see the breather hose.

 

[Clickws]

2015 LX570 with 150k miles recently purchased in Feb 2023. Currently live in South Carolina.

Observations:
- CDL light flashing only (no other indicators)
- CDL light comes on ONLY during cold start (after sitting overnight)
- moist, rainy, post rain, or dew conditions are consistently present for CDL light to come on
- have not made a clear distinction if cold temperature has impact as most of our cold days where we live usually have moisture associated
- when I bought the vehicle, no lights were on and did not present themselves until first wet event; all functioned as it should on test drive
- while CDL light is flashing: will NOT actuate to lock/unlock the CDL
- after warm up and drive for 10+ minutes, the light will go off if we turn engine off and restart
- after warm up and 2nd start, all 4wd functions as they should (CDL, 4hi to 4lo/ 4lo to 4hi, shifting through gears, crawl control, offroad driving modes, etc)

Potential Causes:
- moisture is finding a way into the actuator housing
- poor seal around actuator housing allowing moisture in
- breather hose dryrot/ shrinkage causing disconnection and allowing water/ moisture inside
- water/ moisture getting into the breather hose from above? and directly into actuator housing
- Not being used enough and contacts are sticking or becoming fouled to point of lack of electrical connection
- less likely but for some people there are issues with actual function of CDL or 4lo engage due to wrong transfer case fluid (too viscous) and requires "warming up" before it will actuate properly.
- windshield recently replaced and did not look like it was well done; there may be some moisture entering vehicle to this specific electrical component (not sure where the CDL wiring runs to and where that particular ECM might be)

Actions:
- Transfer Case fluid changed with OEM Toyota 75W Transfer Gear Oil LF
- Put breather hose back on actuator housing after first CDL light flashing event (8 weeks ago)
- I plan to try a ziptie on the breather hose to the actuator housing nipple to keep a good seal and keep hose from coming off
- If moisture has gotten in there, it is probably going to require disassmbly, clean up, and reinstall along with silicone sealing the actuator housing together to keep water, moisture out that way.

Questions:
- Where can I get the instructions for proper windshield installation? Any further suggestions on this? (Not using Safelite or the like) I want to have this windshield redone so it will be a non-issue. Found sketchy site: http://zatonevkredit.ru/repair_manuals/viewdoc/AWI4keo9BFyj9RK37Qpj
- Where does the breather hose for actuator housing run to?

 

[MrM]

Just as an FYI, when I rebuilt my acuators, I used JB weld and built up a SMALL ring around the end of the hose nipple. This seems , along with a zip tie, to hold the hose on better and tighter. Hopefully to keep moisture out better. Mitch

 

[isthatalexus]

2015 LX570 with 150k miles recently purchased in Feb 2023. Currently live in South Carolina.

Observations:
- CDL light flashing only (no other indicators)
- CDL light comes on ONLY during cold start (after sitting overnight)
- moist, rainy, post rain, or dew conditions are consistently present for CDL light to come on
- have not made a clear distinction if cold temperature has impact as most of our cold days where we live usually have moisture associated
- when I bought the vehicle, no lights were on and did not present themselves until first wet event; all functioned as it should on test drive
- while CDL light is flashing: will NOT actuate to lock/unlock the CDL
- after warm up and drive for 10+ minutes, the light will go off if we turn engine off and restart
- after warm up and 2nd start, all 4wd functions as they should (CDL, 4hi to 4lo/ 4lo to 4hi, shifting through gears, crawl control, offroad driving modes, etc)

Potential Causes:
- moisture is finding a way into the actuator housing
- poor seal around actuator housing allowing moisture in
- breather hose dryrot/ shrinkage causing disconnection and allowing water/ moisture inside
- water/ moisture getting into the breather hose from above? and directly into actuator housing
- Not being used enough and contacts are sticking or becoming fouled to point of lack of electrical connection
- less likely but for some people there are issues with actual function of CDL or 4lo engage due to wrong transfer case fluid (too viscous) and requires "warming up" before it will actuate properly.
- windshield recently replaced and did not look like it was well done; there may be some moisture entering vehicle to this specific electrical component (not sure where the CDL wiring runs to and where that particular ECM might be)

Actions:
- Transfer Case fluid changed with OEM Toyota 75W Transfer Gear Oil LF
- Put breather hose back on actuator housing after first CDL light flashing event (8 weeks ago)
- I plan to try a ziptie on the breather hose to the actuator housing nipple to keep a good seal and keep hose from coming off
- If moisture has gotten in there, it is probably going to require disassmbly, clean up, and reinstall along with silicone sealing the actuator housing together to keep water, moisture out that way.

Questions:
- Where can I get the instructions for proper windshield installation? Any further suggestions on this? (Not using Safelite or the like) I want to have this windshield redone so it will be a non-issue. Found sketchy site: http://zatonevkredit.ru/repair_manuals/viewdoc/AWI4keo9BFyj9RK37Qpj
- Where does the breather hose for actuator housing run to?

You are doing and investigating all the right things. Taking the disassemble and recondition plunge on the actuator box is a great way to build a closer emotional bond to the truck, which is important.

Regarding...

- Where does the breather hose for actuator housing run to?

This is discussed and theorized about, but nobody on this forum has arms long and narrow enough to find out. It is a mystery. There are portals.

(maybe from a MUD dream I remember someone mentioning the terminus of the breather, but cannot find post now, nor is my FSM ISO mounting properly, so v difficult to look up. If you figure it out and document, you will here carve in stone your legacy for all time.)