Brake and abs light on after new tires.

[BlackBeauty_bb]

Hey guys. Just have a dumb question. I just recently changed the front tires of my car. They are 255 45 18. I know that not having the stock wheel size will set off the brake light and abs light on the dash after you stay over 60mph. The lights go away after I turn the car off then come back on. Is their a way to reset the sensor or adjust it so it wont power on anymore. it didnt do this before with the same size tires only after I replaced them.

[RubberCtyRauder]

what size are your rear tires?

[fastblackmerc]

Hey guys. Just have a dumb question. I just recently changed the front tires of my car. They are 255 45 18. I know that not having the stock wheel size will set off the brake light and abs light on the dash after you stay over 60mph. The lights go away after I turn the car off then come back on. Is their a way to reset the sensor or adjust it so it wont power on anymore. it didnt do this before with the same size tires only after I replaced them.

You either have to manually turn traction control off, turn traction control off in a tune or put the right size tires on all four corners.

[Mr. Man]

Is your car an '03 or an '04? If it's an '04, the advice FBM suggested might solve the problem. If it's an '03 there may be a different issue. Is there a chance the service person knocked the ABS sensor loose while changing the tires?

[BAD MERC]

Was this after tire replacement or was it a coincidence? My buddy has an '04 and his ABS/brake lights would reset after turning the car off/on. His issue wound up being the ABS module on the ABS ass'y under the intake.

[BlackBeauty_bb]

The rear tires are 275-45-18. This issue only happened after I replaced the front tires. before that the car had the same size all around. So that was what threw me off guard. And I took it back to the shop and they didn't find anything wrong. my rear tires are running very low on thread so Im also wondering if that could be a possibility.

[BlackBeauty_bb]

And my car is a 2003.

[fastblackmerc]

Check all the ABS sensors at each wheel. You might find them loose.

[FordNut]

You need larger diameter rear tires.

[Mr. Man]

If it's a 300A tire size won't matter. Check the ABS sensors to make sure they are on tight

[FordNut]

If it's a 300A tire size won't matter.

It does on mine.

[Mr. Man]

Why? I was under the impression you can run what ever you want on a 2003 300A. Based on your join date I assume your is an A unless you joined before you bought yours and you have a 300B.

[FordNut]

It doesn't have traction control so it doesn't screw up the power delivery, but it does make the abs and brake light on the instrument panel come on. Sometimes people get away with the same size all around, but if the rears are slightly smaller than the fronts you have this issue.

[Turbov6Bryan]

It doesn't have traction control so it doesn't screw up the power delivery, but it does make the abs and brake light on the instrument panel come on. Sometimes people get away with the same size all around, but if the rears are slightly smaller than the fronts you have this issue.

That silver birch of yours at Louisville has 260k???!!!????

Wow, I had no idea

Nice Brian:2thumbs:

[Mr. Man]

It doesn't have traction control so it doesn't screw up the power delivery, but it does make the abs and brake light on the instrument panel come on. Sometimes people get away with the same size all around, but if the rears are slightly smaller than the fronts you have this issue.
So if the OP has 275/45/18 on the rear and 255/45/18 on the front, why would this screw with his idiot lights?

[FordNut]

That silver birch of yours at Louisville has 260k???!!!????

Wow, I had no idea

Nice Brian:2thumbs:

Sorry, I didn't make it to Louisville. Maybe another fordnut?

[FordNut]

So if the OP has 275/45/18 on the rear and 255/45/18 on the front, why would this screw with his idiot lights?

1. The 245, 255 or 275 is width. The 45 is height (not exactly, but relative to width). A brand new 45 will be bigger than a worn out 45.

2. Basic troubleshooting - very basic - If you change something and then a problem starts, they are probably related.

MAYBE if the tire sizes are right on the edge of being ok for the PCM, the rears could be aired up enough to make the lights go out.

[RubberCtyRauder]

possibly as what Fordnut said new 255, old 275

https://www.tacomaworld.com/tirecalc?tires=255-45r18-275-45r18

[Bluerauder]

So if the OP has 275/45/18 on the rear and 255/45/18 on the front, why would this screw with his idiot lights?


possibly as what Fordnut said new 255, old 275

This ^^^^^ may be the root of the issue.

Since the OP makes no mention of a Traction Control light, it is easy to assume that he is talking about a 2003 300A Marauder. Seems even more likely because he was running the same size all around prior to this incident.

The 275/45/18 is 27.74 inches tall.
The 255/45/18 is 27.03 inches tall (2.6% difference).

If the rears are worn down to only 1-2 mm of tread depth on the outside treads, the center tread could be entirely bald due to the center wear issue. In this case, it is entirely possible that the rears have been worn to a point where the rears are actually a tad smaller diameter than the fronts. Past time to replace those rears.

[lifespeed]

It doesn't have traction control so it doesn't screw up the power delivery, but it does make the abs and brake light on the instrument panel come on. Sometimes people get away with the same size all around, but if the rears are slightly smaller than the fronts you have this issue.

Finally another voice of reason! I have been saying for years that tire stagger does not just affect traction control. The ABS is counting revolutions also. All I did was put 255/55R-18 rears on with stock fronts, and I soon noticed premature triggering of the ABS. No dash light or other glaringly-obvious symptom. Just ABS triggering under moderate braking. This definitely increased stopping distance. I consider degrading ABS functionality unsafe and a Very Bad Idea.

Unless you're going to be a hero and try swapping in a Crown Vic ABS module, stick with 5% stagger. It is painful finding the tires. See my sig for a 20" combo, can't help with the 18" stockers but others here can.

[Serge]

You are not low on brake fluid are you?

[EMAS]

Personally I've ran the 255/45 275/45 combo a well as 255/45 all around without any issues so I doubt that is the problem.

What you really need to do to get to the root of the problem is to hook up a scan tool capable of reading the ABS codes and see what it tells you. Is it a code related to a single wheel or are their multiple codes?

[lifespeed]

Personally I've ran the 255/45 275/45 combo a well as 255/45 all around without any issues so I doubt that is the problem.

What you really need to do to get to the root of the problem is to hook up a scan tool capable of reading the ABS codes and see what it tells you. Is it a code related to a single wheel or are their multiple codes?

Good advice to let the ABS module tell you what it thinks is happening. One bad wheel, obvious enough.

That said, I am starting to form the opinion that the degraded ABS behavior with tire stagger error may not be that obvious to everybody. Of course there are no symptoms at all until you are approaching the threshold of braking traction. There, a modest difference in braking force at which the ABS activates may not be noticeable by your average, shall we say, less-enthusiastic driver.

That said I am completely convinced tire stagger affects ABS. I have to believe the ol' seat of the pants and my experience. Not to mention another Nor Cal Marauder owner has confirmed he noticed this behavior.

[BlackBeauty_bb]

I really appreciate all the replies. a lot of trouble shooting for me to do to figure this whole thing out. I will definitely post a reply once its solved.

[FordNut]

Tire stagger does matter. Just swap the OEM fronts and rears and see what happens.

My first experience with this problem was at Marauderville Indy.

Replacement sizes were very limited at the time. I had some wide rears that were smaller diameter than stock, I don't remember the size. I drove up to Indy and didn't seem to have a problem. Went to the drag strip and it tripped the ABS light at the big end. It went back out at normal highway speeds. Apparently I was just on the edge of PCM acceptable limits on difference.

I fixed it without any code readers or any of that other troubleshooting nonsense, I changed the rear tires back to the correct size and just like magic the problem was gone.

[lifespeed]

Tire stagger does matter. Just swap the OEM fronts and rears and see what happens.

But everybody on mm.net says it only affects traction control . . .

;)

[Redster]

Just out of curiosity, are OEM size tires available for the rear from anybody?
I got a set if BFG rears a few years ago. The salesman said they only made them in June and I snagged a set.

[FordNut]

nitto, cooper, falken, firestone, kumho, goodyear, bfg

[ctrlraven]

Personally I've ran the 255/45 275/45 combo a well as 255/45 all around without any issues so I doubt that is the problem.

What you really need to do to get to the root of the problem is to hook up a scan tool capable of reading the ABS codes and see what it tells you. Is it a code related to a single wheel or are their multiple codes?
My abs & brake light came on one day while driving to work. Scanned the computer and found it was related to the rear left abs sensor. Found it to be a little loose, removed and cleaned it then reinstalled it, cleared the code and all was well after that.

[fastblackmerc]

My abs & brake light came on one day while driving to work. Scanned the computer and found it was related to the rear left abs sensor. Found it to be a little loose, removed and cleaned it then reinstalled it, cleared the code and all was well after that.

I've seen that problem on a few MM's.