Larger tires affecting my wheel speed sensor?

[901Memphis]

Running 215/70/15 tires on my Buick with stock size being 205/70/15. My wheel speed sensors aren't working so I don't have abs or traction control. The code was already on the car when I got it with those sized tires.

Is it possible that the tire size is causing the issue all by itself? The wheel speed sensor harness was already replaced as well as the sensors AFAIK by the previous owner but he said the code eventually came back, just not sure if it coincided with the tire swap.

I need to buy two new tires and trying to figure out if I should just go back to oem size or not. The tires and rims are basically stock size from a regal, the rims are from a regal.

My back tires have lots of tread left, but fronts are shot. (heavy foot)

 

[salv]

You need to replace the entire hub assembly. The hubs often come with the sensors already installed.
In a GM, the reluctor ring is in the hub. If it corrodes or breaks, it does not send a proper magnetic signal up to the wheel speed sensor, and ABS codes set.

 

[spasm3]

If the tires are all the same size the sensors/computer will have no way of knowing it. You have a numerically lower, slightly higher final drive with bigger tires. Your spreedometer will read about 1mph to 1.5 mph slower than you are actually traveling. One of the sensors is probably not working.

 

[Doog]

Depending on the sensor style some can be cleaned

 

[901Memphis]

The entire hub assembly was already replaced but I believe that the parts may have been inferior. Might be looking into replacements so I can have my abs back. I could care a less about the traction control.

I have to get down there soon anyways to do a front brake job anyways, might as well make it a party and do the hubs too.

I wasn't aware you could replace the sensor only I have priced them before and it's always one piece hub/sensor.

Funny note, when it's wet outside and the car has been shutdown the lights go away until I use the brakes a little bit and the abs goes all pulsy and the lights come back on.

 

[KitaCam]

here ya go...input both sizes and compare...

http://www.rimsntires.com/specspro.jsp

Keep in mind that the ODOMETER is also affected...

 

[CapriRacer]

Originally Posted By: 901Memphis
.....Funny note, when it's wet outside and the car has been shutdown the lights go away until I use the brakes a little bit and the abs goes all puley and the lights come back on.


Some thoughts:

First is that I have heard of vehicles reacting to different diameter tires. I suspect this has to do with the computer expecting a certain range of values and getting something outside that range.

Second, the quote above seems to indicate that the system is working, but something causing the system to go into default mode - and it could be tire diameter.

But changing only 2 tires is not going to fix that. What changing 2 tires should do is cause the system to recognize the front to rear difference and still not fix the problem - and maybe even cause other issues.

Without understanding what the system does, it's hard to determine what will fix it.

Have you downloaded the fault codes? That might be a good clue as to what is going on.

 

[901Memphis]

I'm replacing the two tires because they are below wear bars.

 

[WishIhadatruck]

As long as all 4 tires are the same diameter, the car has no way to tell the tires are the wrong size and it will have no impact other than your speedometer and odometer will not read correctly (assuming they were correct before).

If the rear tires have a lot of tread and the fronts are at the wear bars, then the wear alone will cause a difference in diameter. This could be the cause, but not likely. I don't know that it would be enough to cause a problem and it sounds like the problem was around before the wear was this different.

I'm not sure how, but it would be nice if you could determine if each wheel speed sensor was working or not. No point in replacing the bearings/hub/speed-sensor if it doesn't need to be replaced. They aren't hard to change however if they aren't rusted in too bad, but they do cost money.

 

[leeharvey418]

Originally Posted By: WishIhadatruck
If the rear tires have a lot of tread and the fronts are at the wear bars, then the wear alone will cause a difference in diameter...


You know that tire carcasses tend to grow as they accumulate miles, right?

 

[CapriRacer]

Originally Posted By: WishIhadatruck
As long as all 4 tires are the same diameter, the car has no way to tell the tires are the wrong size and it will have no impact other than your speedometer and odometer will not read correctly (assuming they were correct before).....



I used to believe that to be true, but I've talked to several people who experienced problems when they change tire size, so I don't think this is true. I don't exactly know what is going on, but I wonder if there is a sensor that senses the ground motion - or one that uses inertia affects to calculate speed. In either case, I no longer assume that you can put on different diameter tires and there won't be any issues.

 

[901Memphis]

I had the codes pulled at Autozone and I believe it was only showing the front left sensor code but I was told that I should replace them in pairs. I need to double check though. Since it shows one side it only it leads me to believe that the tires have nothing to do with it.

Either way I only have to pay $250 for matching front tires, I don't think I can afford a whole new set atm even though I want better ones.

My current tires are mastercraft avenger gt 215/70r15. I really like the wider tires for aesthetics alone but if I knew it was causing the issue I would probably get 4 oem tires.

 

[KitaCam]

Tires don't always measure as spec'd....hence another source of variation (and unknown impact if not measured) on speedometer/odometer readings.

 

[901Memphis]

With my oversized tires, my odometer reads tick for tick with my gps odo. I guess maybe it was off with the oem size, which i am told my a former GM employee they have a certain margin for error they are allowed in the odo anyways.

 

[KitaCam]

Yes 901M....EVERY one of the 12+ rides I've owned was off by +2mph ...until the Camry which was off by +3mph...when I went from 15s to 17s the speedo "dropped" to +2mph...
But also...
...the odometer is now off by a MINUS 2+%...I can't be sure HOW much because the mileage posts are off and differ on different highways...but it reads at least 2% under, sometimes 5%...