abs light comes on after moving but after restart is off till moved again

Hello,
I'm hoping someone has had this same issue and can shed some light on this problem. I have searched through the forums but have not been able to find a similar issue.

here are the details:
2004 Tundra SR5 double cab 4.7 Auto 170k.
ABS light came on with no change to braking or behavior.
When starting truck the light is not on. Only comes on after moving truck a few feet.
Stays on until truck is shut off. It is not intermittent. Consistently comes on after moving the truck a few feet but is off after restart.

I've tried multiple scan tools including the new launch 2024 x431 and all scan tools state no abs present.

I'm kind of at a loss as to what's going on. Any input that someone would could give would be most appreciated.

 

Have you confirmed your brake fluid level? It sounds like it could be right on the line for the sensor and as you move, it's tripping the light on/off.

 

I saw something like this with a 4th gen 4R (2004). It was a small switch that is actuated by the brake pedal. If FGT is similar, it will be visible looking upward at the break pedal. Comes out with a quarter turn, runs about $20.

 

Actually I have seen the brake fluid level check come up on multiple posts. To be honest I haven’t and will do today. I’m curious though as to why multiple scan tools are not recognizing the abs at all?

if I’m not mistaken I do recall a brake light switch position sensor code that showed a status of history, which I cleared. It does seem that compared to my 1st gen sequoia, I have to apply more brake pressure to shift out of park.

 

Which is a sign of a possible leak, or need for pads

 

So I'm not sure a scan tool will confirm low brake fluid. I don't think it's the same as diagnosing a check engine light.

 

I do understand that low brake fluid level will not be detected by a scan tool but was more curious as to why multiple scan tools have not been able to even detect that the truck is equipped with abs. I've run the scan tools after the abs light came on with no success as far as detecting any codes. as I've mentioned as soon as I shut the truck off and start it again the light will be out and will only activate after I've moved the truck a few feet or I suspect after I reach a certain MPH. Check engine light does not activate.

 

What scan tool are you using? When I was trying to diagnose ABS issues a few years ago the shop had to use a very expensive SnapOn diagnostic tool. It was able to tell me which wheel speed sensor was having issues. Our old trucks are not as tech savvy as the newer ones.

 

Look at the fluid level and then get back to assumptions

 

It's likely your ABS/wheel speed sensors, either one of the front, or a rear. Have you recently done anything with them lately?

I'd pull the front ones, check for garbage, clean, fully seat when reinstalling, and tighten down.

I'd check the rears if cleaning/reinstall of fronts doesn't resolve. Also check for rear seal leaks while in there.

The reason I say it's the ABS/WSS is because it only triggers when moving. This reaks of sensor issue.

 

I need to go back and read my old posts but I don't remember if my light came on when I was having WSS issues. It would trip the ABS at low speeds though. My ABS fuses are pulled now so the light stays on.

 

As far as scan tools are concerned, I haven't used a shop level scanner as of yet but more advanced dYI scanners. The most recent was the Launch creader x431 elite for "Toyota/Lexus. Prior to purchase I did some research and was able to determine that the scanner was pretty close to techstream. I have techstream but was not able to find any usuable download and am not sure why the installed version stopped working. I know toyota is going to a cloud based service so the launch sounded like a viable replacement for techstream.

Shifty,
I think your absolutely correct but was hoping to be able to pinpoint which sensor with a scan tool hence my delima with wondering why scan tools are not picking up abs module at all. I guess I'll just have to suck it up and tear into sensors and check condition. I haven't done anything recently to the truck. It sits alot and I'm in the Pacific North west so who knows what kind of crud is built up.

Firstgenvol,
I agree, it's probably due to the age of the truck, (less technology) but I have a 2003 sequoia that the scan tools do detect the abs system on???

I'm off to check the fluid level just for elimination purposes. I'll report my findings.

By the way, I'm brand new here and this is so amazing!!!! To be able to bounce stuff off of other Tundra owners and I want to make sure that everyone completely and totally understands the value of this resource!!! Thank you all!!

 

@shifty` is the GOAT at helping but we all try to chime in when we can. Try to stick around. We get a lot of new members that ask for help and then disappear. Let us know what you find out.

 

PACNW trucks aren't typically too bad.

There likely is some way to use a scan tool to check the sensor output, but ... Seriously, up front, it's only one bolt holding them in place and you technically don't need to remove the wheel to get to them, I don't think? 10mm bolt IIRC, pop it out, wiggle the sensor out, check for debris on the end, wipe it clean and dry, wiggle it back in evenly (they must be square to the tone ring, seating is important!), and bolt back down. Repeat on other side, and it may be easier if you kick the wheel to full lock to gain access to the sensor itself.

In back, I haven't had to touch mine, so I'm not fully clear. But I know people who fail to replace/maintain the breather vent valve on top of the rear diff ... if that cheap $10 valve freezes up, and the rear diff can't off-gas as expected, you'll ultimately blow out your wheel seals because build up pressure will seep out there. Gear oil and crud will seep in where the sensor is and jam it up.

Anyway, 20 minutes to check both sensors up front, total. Tops. Maybe only 10. Inspect them. Reinstall. If the problem still happens, hit us up.

 

Here is a quick update but still working on issue. I'm going with shifty's intuition on this one. What I've done so far.

Checked fluid level. Ok although a little dirty. next on my to do list for maintenance,

Jacked up front tires and spinned them manually one by one hoping it would trigger abs light. Fail. I don't think I could spin them fast enough by hand.

Jacked up rear axle and got drivetrain up to past 20mph. No trigger of abs.

Drove truck and sure enough after about 7mph the abs light came on. So narrowed down to front.

While having truck up in the air checked for any obvious leaks in rear seals as suggested and all seems dry.

Pulled driver side sensor and I've attacahed a pic for your examination. Seems pretty clean to me.

I'm now going to pull the passenger side and see what we have.

Something to note. When I went to spin tires manually the passenger side was a little stuck?? Driver side was pretty free. Passenger side did have more exposure to weather so it will be interesting to see the condition. Did check pads and condition of rotors and they seem to be well above 70%.

p.s I did go ahead and wipe down the sensor.

 

Is it possible it's coming from the driver's side, and you've got a bad wheel bearing, or stuck caliper, and it's causing the wheel to drag, which is tripping the ABS, tricking it into thinking one of the wheels is stuck, or the other is spinning, i.e. you're having a traction event?

Do you see any signs on the front or rear of the rotor that maybe something is stuck? If you remove the wheel, does the wheel still spin slowly? If you remove the caliper, does the wheel still spin slowly? (trying to narrow down if caliper is sticking, it's not uncommong to get a stuck piston)

EDIT: Tone ring looks fine on that side. I don't have beef with the condition of that sensor either.

 

Just finished looking at passenger side. Was a little wet?? Not sure what that's about but rotor is definitely dragging compared to other side but not to the point that I have to use great force to spin by hand. You're right about sticking calipers, had this issue with my first gen sequoia but never got abs light. Same drive train i believe. Going for road test, although I try and remain positive I don't think there's going to be a change.

 

I meant passenger side above, I guees I misread.

It's curious. And it almost seems like the passenger side is more common side to have caliper seize, I wonder why?

It could just be the sensor is bad, but man, I wouldn't wish that expense on anyone...

 

Forgot to mention im pretty sensitive to drive ability and I think I would of noticed a pulling to right.

 

Yeah, you're probably right about bad sensor. Would of been nice to be able to pinpoint bad one. I'll keep you updated.

 

A lot of times you'll get a shimmy also.

I worry about heat buildup. And what heat buildup could do to, say, a ABS/WS sensor, for example. Got a junkyard anywhere nearby you can snag a replacement from?

 

I didn’t notice when my caliper was sticking. It’s been the drivers side twice. Also the 6-7mph thing is when the ABS self check happens. It’s likely faulting at 7mph after the self test fails. Could be WSS, could be the ABS module itself.

 

Knabores, true and true. I do know the rear axle does not trigger the light. Lifted rear axle off ground and got up to about 25. No light.

 

In my little town Autozone has a code reader that reads ABS codes. Have you tried that?

 

Hmm. Didn't know that bfunke. I called my local stealership to see how much they would charge just to plug into techstream and pinpoint. They are a little more flexble than other stealerships and might do it for 20 bucks, who knows. Not going to pay 150 though for a diagnosis.

On a side note. I noticed they are selling a set of sensors for less than 100. The seller claims to offer a lifetime warranty...lifetime of what??? who knows. I might get the set just to see if it eliminates my problem and if it does I'll use them till they die and work on getting the very pricey oems.

I wanted to thank everyone for your help. You guys have been great and I will update when the problem is solved. I've got much more to deal with as far as little quirks here and there so I guess I'll be talking to you guys down the road.

 

Depends on the seller whether I trust it.

Sadly, "lifetime warranty" doesn't equate to "it'll last a lifetime" these days, it only means "when it inevitably goes bad in a year or two, *IF* you actually still have the receipt, we'll exchange it, at least once"

 

You're absolutely correct. I did check loads and loads of feedback on the sensors for my vehicle and it was pretty good. I'm going to cheap out this time. I try and only buy oem but since this is not a crucial item as far as safety is concerned (not sure if this will make my abs system unsafe) I'm going to give it a shot and see about scouring the web for a great deal. I'll update after installation and give periodic updates on the aftermarket sensors.

 

Hey @stevosupremo I was looking at another issue today and thought you may want to see this thread too: https://www.tundras.com/threads/slow-speed-abs-activation-fixed.131442/