ABS Issue? Dash Lights are 4hi, 4lo (Flashing) Trac and ABS (Solid On)

I posted a bit about this in the "What have you done to your 2nd Gen Tundra today?" thread but figured it would be better to post this in it's own thread.


My Truck: 2010 SR5 4x4 FFV with 125k miles.


Here's the scoop. Saturday afternoon right after a 300+ mile trip to Buckeye and back, my 2010 lit up like a Christmas tree. The lights I'm getting on the dash are the following: 4hi, 4lo (Flashing) Trac and ABS (Solid On). That's it. No other lights, or combination of lights.


***Having said that, the truck runs/drives just fine. No hesitation, no stalling, no power loss, no limp mode, etc... Just a bunch of lights lit up on the dash.


One thing I did notice last night is the flashing 4hi/4lo only starts once the ABS system has done it self-check (That little clunkish noise you hear after driving about 20 yards). Once it completes the ABS self-check the 4hi/4lo lights illuminate and flash. The ABS and Trac lights illuminate as soon as you start the truck.


Many different Google searches for this specific set of trouble lights point to an ABS sensor issue and typically ABS trouble codes of co210, co215, etc, which apparently identifies which sensor is having the issue.


Here's what I have done so far.

-Disconnect battery/computer reset: 3 times over 2 days, 15 minutes minimum each time. (pro tip: disconnect horns before reconnecting the battery. Alarm is LOUD!)


-Scan for codes: 3 times with 3 different scanners. My scanner is cheap and doesn't deep dive for ABS codes. Neighbors SnapOn scanner does ABS but found no codes, Auto Zone scanner does ABS but found no codes.


-Traced all 4 sensor wires looking for damage, chaffing, rodents, etc...: Nothing


-Removed/Inspect/Clean each sensor: Each sensor and sensor pocket was gently cleaned with MAF cleaner and reassembled.


This was somewhat interesting as I found I probably need to do rear axle seals sometime in the near future as there is a dry, crusty, crud/gunk in the rear/driver side sensor pocket and goopy oil/water mix in the rear passenger side sensor pocket. Front sensors and pockets were pretty darn clean but got cleaned anyway.


Here's what I wiped off the driver side/rear sensor on the first wipe (no pic of sensor before wiping), and what I got out of the pocket.





This was the passenger/rear sensor before cleaning (YUCK!).




OH! Just FYI. I changed the rear diff oil to full synthetic back @ 108k miles. After seeing the goop on the passenger/rear sensor I went ahead and drained the diff again. There was NO goop or water/oil milkshake when I drained it @ 108k and there was nothing when I drained it this time (125k) either. Weird?


Anyhow, if anybody has any ideas of where to go next, I'm all ears.


And yes, I realize I need to attend to the axle seals but I won't be doing that for a least a few more weeks.


Thanks in advance.

 

Could be a bad battery or the battery is going bad / low voltage....

 

Textbook turbo/wastegate problem. Good luck!












Had a bad ABS sensor on my old truck. Look fine, no damage. I don't remember if i had 4x4 lights tho. I would swap out the one that had all the crap in it.

 

Voltage right now, after not being driven since last night. Battery date is 9/19.


Voltage at idle is 13.78.

 

Had a similar problem.


Bad Body ECU.

 

Hmmm... According to the chart I have a "Transfer case shift failure".

So, I just went out to the truck, started it up, ABS/TRAC lit up (double checked to make sure I'm not missing an additional light. Nope!), backed out of the drive and shifted to 4hi before it had a chance to do the ABS self-check. No problem there. Could hear it engage (also verified it engaged by a bit of front end binding when turning around). Back to 2wd and got the blinking 4hi/4lo.

Stopped and shut it completely down again and restarted. Again ABS/TRAC light up on restart. This time put it in neutral, switched to 4hi, then to 4lo. Same thing, could hear it engage both times, drive to turn around and get a bit of front end binding confirming it is indeed in 4lo. Stop, back to 2wd and get the flashing 4hi/4lo.

I did order a couple of new sensors, one for each side, this afternoon. Should be here tomorrow at which time I'll swap them out, one at a time, starting with the rear.

It seems the transfer case is doing what it should be doing.

 

I do have a Bully Dog tune flashed to the ECU. It's been there for a couple of years now with no issues. I may try reflashing back to the stock tune and see what happens.

Thanks for the input.

 

There are 2 ECUs. One is inside the cab and the other is under the hood. Mine was the body.

 

Got it! Is this on your 2016 truck?

 

Yes

 

On the GX470 a bad gas cap can give you all those lights. Might be worth trying a new o-ring on it.

 

A bad gas cap will also give a readable OBD code. Really the OP should go to an autoparts store and borrow a better scan tool to see what the trouble codes are.