jbc1995fb

On the way back from Austin my Abs/active handling light came on. Took the car to o'reilly's and the code was C0035 - LF wheel speed circuit. They couldn't reset it. Took it to autozone, advance auto parts and a Just Brakes store to see if they could clear the code. No luck.

So what could be the problem and expected cost for replacing said sensor?

Any other advice?

Oh, it's a 2012 GS, automatic. Has new tires.

Thanks, Jason

ChevyDave

did your code SAH message happen right after your new tires?
1) if yes... what are the sizes of the front and back. (correct production size?)
2) if yes... it's possible the connection at LF speed sensor was altered (made poorly) and causing C0035 when you got new tires


the code will most likely reset when your problem goes away and if you have a TechII code reader reset it. Generally , you wont get rid of the code as long as the speed sensor is failing, due to bad connection or bad wiring or faulty sensor

cost might be just resetting connection or cleaning contacts.

See Bill's posting on this here.... https://www.corvetteforum.com/forums...ters-mean.html

Dano523

Wheel speed sensors are in the wheel hubs, but chances its either that the connectors was pulled loose, or one of the wires in the connectors pulled loose from it's wire clip in the connector instead.





So I would start off with un-clipping the LF connector, clean both sides with electrical spray contact cleaner, and when you plug it back in, push the wires back in the back connector as well.


As for tire sizes, easy check and make sure the the rear sizes tires are 1.04" larger OD than the front tire sizes.

http://www.discounttire.com/dtcs/infoTireMath.do

jbc1995fb

The tires were put on about a month ago. Michelin tires, factory size on front; went with 345 on the rears. No problems until today.

Thanks for the advice. I'll check the wheel and tire as suggested.

StKnoWhere

There is another connector at the frame. A replacement cable is about $30 online. You can test by first swapping left and right cable and see if the code moves.

Wheel Sensor ACDELCO Part # 15248662 ABS Wheel Speed Sensor Connector

Guard Dad

Don't know if it is really a problem but most folks that make the jump to 345's bump the front tires up to 285's to better keep the diameter difference within factory spec.

ChevyDave

general rule of thumb (not absolute) as to size difference limits...

front must be..
min is rear dia * .942
max is rear dia * .980

back must be..
min is front / .98
max is front / .942

i know others have used 345/30/19 with their 275/35/18 just fine. but doing the calc, you are right at the max limit, and i suppose unusual tire wear diff between front and back could later in the tires life, cause errors

each manufactor actually has slightly different tire dia for a size, but the calculator (that Dano listed and that i use too) is accurate enough for our purposes.

275/35/18 = 25.58"
345/30/19 = 27.15"
27.15" * .942 = 25.5753" (right at limit of the 275 which is 25.58)
285/35/18 = 25.85" which (as noted in above post) is "better"
(NOTE: i suspect that its really Circumference what we should be concerned about, but i've never located any articles with that as the 'difference' factor)

(i plan on replacing my 325 Nitto's with 345 when 325s wear out)

Dano pretty much gave you the best possible reason for code and solutions too!

jbc1995fb

Update:

I took the above advice and tried cleaning the cable but the light stayed on.

So I finally took my car to the shop (better late than never) and they said it was the wheel speed sensor.

Corvette505

Thanks, this is a really helpful thread.....great pics and detail

Corvette505

WTH, I took mine to O'Reilly and they said they couldn't read abs codes on a Corvette, ugh!!!

bo_knows

I know this is an old tread but Bluedriver device at Amazon for $99.95 can read this and any other Corvette codes.
My code is C0050 RR wheel speed sensor circuit malfunction.

bo_knows

Did mechanic ever mentioned/disclosed how he figured out that sensor was bad? Just wondering since I have the same issue.
GM dealership charged me $1000 for the replacement of the rear hub and the alignment. I'm still receiving the code (C0050) but now on the other rear right hub.

Dano523

Best guess, either the wheel hub sensor when out, sensor connector problems, or you have a connector problem at the ecm or in the C186 connector next to the the battery. To get to the C186 connector, you need to pull the battery since it about half way down on the fender wall side next to the battery.

The rear hub sensor wires come off the ECM, through the C186 connector (#5), then down that loom to the back of the car.

Here is the C186 connector and rear harness, and as noted, most of the time you have a broken wire, its at the hard outer sheilding start section since it not a flex point for the loom before it off the connector instead. Hence loom from the hard section back moves with the torque tube so you don't normally have a broken wire at the back of the loom, while the section at the front of the hard section is the kink movement point isntead. Combine that with the tiny gauge wire GM uses for some of the lines, and its a problem just waiting to happen.







Also, the rear wire loom has a center hard outer section about middle point of where it secures to the torque tube, and its not uncommon for one of the wires to crack at the beginnning of the harder out shelding point. So what I do to make sure that one of the wires is not broken, is disconnect the C186, disconnect the wheel hub sensors connectors, use pins to ground all 4 wires to ground, then go to the rear sensor connector to make sure I have continuity to ground on all the pins. This weed out a rear loom broken wire problem, and will go one step farther is needed, to disconnect the ECM connector to do the same on the ECM to C186 connector to check the 4 wires on that side too.

bo_knows

You are awesome! Thanks a lot.

Cleaning my connectors and clearing the code worked (for now).

Contemplating on buying the shop manual.

VETFEVER

Some great insight here.

vetfever

Dano523

Yep, someone at GM should be shot for putting the two main connectors next to the battery.
If you look at the vent port for the battery, it going to vent at those connectors, and can cause all kind of corrosion problem sooner or later.

mlguerrero06

Thank you for the info.

mlguerrero06

All this is great information, and I greatly appreciate all the input. I'll be troubleshooting this weekend, and I'll put a follow up in here.