How do you diagnose which speed sensor

[zoomie]

Hello all;

2003, ecotech, manual, new michelins, 50,000kms, I've had it for 4 months and put the last 20,000kms on it.

Had the "ABS, SVS, and Track Off" come on each time I start the car and travel 15 ft. Once in a while the ABS kicks in with the noise and peddle pulsation just before the lights come on. All this in warm dry weather. My cheap $100 OBDII reader does not read any codes.

I do 200 highway kms a day and there is no worn bearing noise to give me a clue as to which side it is. I don't even really know if it's front or back. In fact the car runs real smooth, good mileage, and I'm happy with it otherwise.

I'm pretty good with the wrenches, breaks, clutch, rads, but I'm new to electrical testing. I've installed radios and speakers but that's just following instructions and soldering the right wires.

I've read the posts for changing the hub and the one about testing with a multi meter.

1. Could someone clarify the "muli meter on the hub" test

2. Is there a different way for a dyi guy to test the sensors in the hubs?

Thanks

[pawzbear]

get it diagnosed by a professional. Even if you DO get a code, that is NOT a 'fix-all' I dont know why people are under the impression that scanners are magical. Also, any decent shop should have a Tech II GM scanner which is does EVERYTHING any dealership can anyways. Decent scanners cost thousands of dollars and i know, we have 2.

[sound_xtreme]

i diagnosed mine by unplugging the harnesses one by one and plugging my new hub in.

[comanche]

Originally Posted by sound_xtreme

i diagnosed mine by unplugging the harnesses one by one and plugging my new hub in.

Great idea. As long as you know at least one sensor is bad, & you know you'll have to buy another one anyway, do what he said.
How come I never thought of that?

[zoomie]

Thanks guys.

My lights don't always go on until I start driving so I'm not sure that would work.

I was sniffing around on another site (actually the oldmobile site that reccomended this site to me) and some said you could use an ohm meter to test. Here's what I found.

First I had to buy a multi meter. They were on sale last weekend for $20.

Jacked up the front of the car and took the ABS connector appart at the hub. Tested the sensor with the ohm meter and got reading of a little over 1000. That's consistent with the other guys good reading. He said he tested a new hub on the bench.

The other side gave a reading of 0. That indicates a bad sensor in the wheel hub. I still have to to repalce the entire hub but now I know were to start.

By the way, I tried to test the rears but they are very difficult to get to with the reader and since I found a bad one up front, I'll replace that and see what happens.

[zoomie]

By the way, my dealer needs 2 hours at $95 just to diagnose the issue. If I wanted to do that, I wouldn't waste my time typing here. I guess you have to pay for that TechII somehow.

[misslindseysue]

Um... yeah. A Tech II (not sure about a generic scan tool - I should try mine) will tell you which one it is. And the hub can go on either side, so you could buy one first, then try plugging it in and seeing if the light went away. But... best to scan and find out for sure. I was convinced that it was the right, bought the part, brought it to the shop, and they called... "code says left, you still want to replace the right?"
A dealer might scan it for you for free if they're feeling nice and aren't busy some day. Just roll in like "these lights came on, can you quick scan and tell me if it's anything I have to do something about right now?" I've had some dealers scan it for me no problem, and some will try to make you make an appointment or pay for it. In that case I just took it to autozone and used a gst (generic scan tool).

[zoomie]

Brighton? I used to work Auburn Hills.

In Canada, the Parts Places won't scan your car cause they call it "diagnosis" They'll test an alternator if you bring it in, but they won't go near a car.

Been to three dealers and even my local shop. They won't go near it without 1.5 hours agreed to. Dealer is 95$ and local shop is $65. So I bought a reader for $100 and now I can read codes.

I know the reader does not give all the codes and even when I get a code I need to know how to test for the actual problem, but for a dyi guy it's a lot better than looking at an idiot light and handing over my checking account to a dealership.

Hey zoomie, did you get your wheel hub fixed? Was it the right one?

[zoomie]

Originally Posted by badgrl

Hey zoomie, did you get your wheel hub fixed? Was it the right one?

Works busy so maybe in a couple of weeks. Definatley before it get's cold.