Finding bad wheel speed sensor

alerored04 · 02-10-2010, 02:23 PM

I will be repairing my 6th hub/speed sensor tomorrow using a part from my sisters wrecked GA. Previously I have been at college where my roomate worked at a GM dealer and had access to a tech II to determine which sensor was causing the issue. Now that I am done with school I refuse to pay my local dealer $60 to plug the thing in and tell me which one is the issue. Is there a way I can use a multi meter or something to find the unit giving the bad signal?

StoopidAlero · 02-10-2010, 02:25 PM

Ive just put the car up on jacks, and then slowly accelerated. The hum is pretty clear which side its coming from. But Im sure there is a more scientific way to do it

Redog · 02-10-2010, 02:41 PM

If you get the SVS, Anti-lock and Trac Off light, is it only the front wheels or could it be the rear?

Just got the hub lights the other day, This is only my 2nd hub in 115,4xx miles

jayson_waltz · 02-10-2010, 02:42 PM

^thats if a bearing is bad. a bad sensor won't hum.
sorry alerored, if i wasn't at college and still working at home i'd throw up the list of what everything is supposed to ohm out to form the gm manual. but i'm not.

and redog, it could also be the rear i think since they also throw codes i've seen b4 in the tech 2.

alerored04 · 02-10-2010, 03:23 PM

Redog it can be the rear too.

Jayson, do you know where I could look to find that info? That would be a good start for me.

jayson_waltz · 02-10-2010, 05:31 PM

^cliff might have that stuff, he seems to be able to get info from the manuals. it's in the section to diagnose SVS codes i think in volume 2. only place i've seen it is the GM service manuals at work when diagnosing mine. I had it copied off once but i threw it away.

Redog · 02-10-2010, 08:45 PM

Quote:

Originally Posted by alerored04

Redog it can be the rear too.

That's what I thought

worknprog.99 · 02-10-2010, 09:18 PM

ok thread jack.. i have anti lock light and trac off light NO SVS , and the code reader said speed sensor failure right front... does that require the whole hub bearing changed?

NONE · 02-10-2010, 09:31 PM

one more, if i have an anti -lock light, track off light, s.v.s. light, and e-brake light that would b a rear one right? or doesn't it matter? and yes my e-brake is fully released when this happens, it just thinks its on.

99alerogirl · 02-10-2010, 10:12 PM

Quote:

Originally Posted by worknprog.99

ok thread jack.. i have anti lock light and trac off light NO SVS , and the code reader said speed sensor failure right front... does that require the whole hub bearing changed?

i'm with this guy! mine said right front as well. but i'm not sure if it's the sensor coming from the car, or the one attached to the hub.. since it came on after i replaced the hub...

StoopidAlero · 02-10-2010, 10:53 PM

Yes, if you are throwin speed sensor codes, you gotta replace the whole thing since its a sealed bearing with the sensor inside. IFRC

jayson_waltz · 02-10-2010, 11:31 PM

Quote:

Originally Posted by worknprog.99

ok thread jack.. i have anti lock light and trac off light NO SVS , and the code reader said speed sensor failure right front... does that require the whole hub bearing changed?

Quote:

Originally Posted by 99alerogirl

i'm with this guy! mine said right front as well. but i'm not sure if it's the sensor coming from the car, or the one attached to the hub.. since it came on after i replaced the hub...

if it says the wheel speed sensor is bad, yes its a whole hub change as its built in. there is no other wheel speed sensor but one per wheel.

Quote:

Originally Posted by NONE

one more, if i have an anti -lock light, track off light, s.v.s. light, and e-brake light that would b a rear one right? or doesn't it matter? and yes my e-brake is fully released when this happens, it just thinks its on.

the e-brake i'm guessing is a separate problem. there its a different sensor that detects when thats on, not the wheel speed sensor. The other light tho do point to a WSS.

alerored04 · 02-11-2010, 12:33 AM

E brake light points to low brake fluid as a first guess. Start there.

Cliff8928 · 02-11-2010, 01:22 AM

Quote:

Originally Posted by jayson_waltz

^thats if a bearing is bad. a bad sensor won't hum.
sorry alerored, if i wasn't at college and still working at home i'd throw up the list of what everything is supposed to ohm out to form the gm manual. but i'm not.

and redog, it could also be the rear i think since they also throw codes i've seen b4 in the tech 2.

Quote:

Originally Posted by alerored04

Redog it can be the rear too.

Jayson, do you know where I could look to find that info? That would be a good start for me.

Quote:

Originally Posted by jayson_waltz

^cliff might have that stuff, he seems to be able to get info from the manuals. it's in the section to diagnose SVS codes i think in volume 2. only place i've seen it is the GM service manuals at work when diagnosing mine. I had it copied off once but i threw it away.

Quote:

Originally Posted by GM

3 Raise and support the vehicle. Refer to Lifting and Jacking the Vehicle in General Information.

Disconnect the wheel speed sensor connector.

Measure the resistance across the wheel speed sensor.

Does the resistance measure within the specified range?

Front: 1040-1160 ohms

Rear: 1044-1276 ohms

Yes? Go to Step 4

4 Spin the wheel.

Measure the AC voltage across the wheel speed sensor.

Does the AC voltage measure greater than the specified value?

100 mV

That should help...

alerored04 · 02-11-2010, 09:33 AM

Thanks a bunch Cliff. Just to verify, those are correct readings, as in a reading other than those identifies the bad sensor?

jayson_waltz · 02-11-2010, 10:35 AM

yep you want the readings within that range. if its bad it'll likely be quite a ways off.

alerored04 · 02-11-2010, 11:21 AM

Awesome! Thanks a bunch for the help guys.

Runaboveit · 02-12-2010, 02:08 AM

I say this should be pinned. Good info...

colonel6632 · 03-16-2010, 12:44 AM

bump so i can find later