4hi flashing

I've got a 2008 tundra, i recently tried switching to 4HI and the vsc off light came on like it usually does, its solid and not blinking and the 4HI light started blinking and it won't stop blinking. Ive tried switching it to 2wd and its the same thing, a solid vsc off light and a 4HI blinking. There are no other lights on and it drives fines. Any ideas?

 

Do you do it while rolling? Sometimes mine will take a good 30 seconds or just rolling down the block. You can shift in 4Hi on the fly between 0-50mph safely. (Definitely be stopped, and in neutral, before going to 4Lo though)

 

Yeah, it does it constantly. After unplugging battery and stopping and turning truck off it just constantly flashes. But it is driving fine.

 

Hmmm that doesn't bode particularly well in my humble, limited 4WD experience. In my understanding there's two actuators in the transfer case - one for 4Hi and one for the planetary gearing in 4Lo. Does it go into 4Lo well at all, when stopped/in neutral?

What temp is it where you are? Are you doing some driving to warm up that transfer case fluid a bit before trying to shift it around? My 4Lo takes forever unless I've warmed it up in 4Hi a little, for example.

Otherwise I've heard it can "lose its place" when shifting between 2WD and 4Hi and 4Lo if the power is cut / engine turned off before it finishes finding its shifting. I believe the fix for that is to crawl under and power the actuator directly at the 12V line so it positions itself, which it won't do if the sensors have teh dumb presently.

 

It was around 50 F in my area today. I let it run for about 5 minutes before i started driving anywhere. I haven't run the 4wd in awhile so I was going to put it in 4wd and drive for a bit. I did the normal procedure and everything started out fine, it just kept blinking. It starts and drives fine, no issues there, it just keeps blinking. There is no "buzzer" sound like it says on the sun shade. It won't go into 4LO, it just flashes on 4HI.

 

Ahhh yeah unfortunately I think the actuator motor might be stuck or the sensor in there has lost its place. I wish I could offer better advice here, I'm a newbie to trucks and Tundras as a whole and have only been learning for a couple months, hopefully someone else can chime in with some ideas for you other than "well, time to head for the shop".

 

The flashing means incomplete shift. I have been fighting with this issue consistently for a week every day after work, the only way to get flashing lights off is to manually help it complete the shift. Open the actuator(fair warning your opening a can of headaches). And manually pull or push the rod that is stuck and make sure you set all the timing to the correct spots, there is a little spring on the front rod that you can set just by pulling the plastic gear off and moving it to the correct place, and there is two little black dials that need to have the lines lined up. I can get more specific if you need more help, unfortunately I did not take and pictures but can walk you through any questions

 

I just thought I’d add to this again try shifting out of 4wd while it is in neutral with just a touch of gas to get your battery gauge up where it should be(mine goes a little lower at idle) and shake the steering wheel back and fourth.

 

I've never had experience talking something like that apart. What could I mess up trying to do any of that?

 

Every gear in that box is plastic and will snap teeth if each timing mark is not in the right spot, I went through about two of each gear getting it figured out. For a whole brand new actuator on Amazon it’s like 188.00$ It’s not that bad it’s just very specific on how it goes back together or it won’t know where it self is. It’s really simple it’s just lining up the two dial mark with the lines pointing at each corresponding mark.and putting each gear on the right tooth, in relation to how you set the rods.

 

I appreciate all the info. Is there any gears i need to order before I start taking it apart to stop tge flashing?

 

I wouldn’t be concerned about it, just pull it apart, I bought the one off Amazon(it was the cheapest I could find) I doubt anything is broke. she just wants a little help and cleaning and lube, pull it apart be very careful to take notes or photos if you don’t want to do it 18 times in 5 days.

 

I'm the kind of guy who already has no patience so i can see a few words and tools getting slung from under the truck already

 

Yeah and keep your fingers on the rods as the like to slide right out , they are tiny and slippery there will be two of them

 

There are a couple very thourough threads on repairing and retiming the actuator if needed, do a search for them. Photos/videos/etc.

Can you hear the transfer case actuator "wind up"? If it's silent, it's likely time to look into the actuator. If you can hear it running it may be something else in the system.

 

When I've been lax about locking mine in 4wd regularly I've had it take 5-10mins of driving before it finally locked in. From then on, engaging it regularly kept it working properly.

 

Its definitely been several months since I've had to use it. Im in Alabama and ive never had to use it in the summers. Ive never had to use it in the winters because it never snows but id rather be safe and make sure it works just in case i actually need it.

 

The Owners Manual recommends putting your Tundra in 4WD at a minimum once a month and running it for 10 miles. Ideally on a low traction surface like a gravel road, but a straighter highway also works.

For your present situation I’ve had luck with turning the vehicle off, turning the 4WD dial to the desired state, and turning it back on, with the transmission in either Park or Neutral.

Here’s a helpful thread on the issue: https://www.tundras.com/threads/2007-2020-transfer-case-actuator.61182/

And this: https://www.tundras.com/threads/front-diff-transfer-case-actuator-diagnosing.51474/

 

I have a 14 and mine threw the traction control and abs solid with blinking 4 hi and 4 low. Check your wheel speed sensors and the harnesses. My issue was the harness being sliced in the rear end that goes to the wheel speed sensor. Definitely check those two things first.

 

I had the same issues (incomplete shift, check VSC message, dash lights flashing) with the 4Lo and center diff lock actuators in my LX570. Here is what worked for me:

1. Fresh transfer case oil.
2. After your truck is warmed up (this is important), put it in neutral, and keep your foot on the brake.
3. Shift it into 4Hi. If it results in an incomplete shift, power cycle the truck, and try again. Keep trying it.
4. Do the same thing with 4Lo. Make sure you’re stationary with the transmission in neutral.

It took a few days of doing this, but my LX’s actuators both work smoothly and quickly now. The important part is that your truck is warmed up. I did it every time I got home from a trip.

Now that it’s working well, I’ll back off the frequency to weekly. If that goes well for a month or so, I’ll back it off to monthly.