OneFasTT997

I'm getting a code C 1234 and I am pretty sure it's a bad speed sensor. I was looking at the SKF hubs but I didn't know if they came with bearings or not. Is there a hub only replacement option?

OneFasTT997

The hub is on the car. I guess I could put it in gear with it up on stands and try reading it then.

LoneStarFRC

You need to disconnect the connector plug closest to the wheel to measure voltage. No need to start car or have engine driving the wheel, which can be dicey anyway, and you certainly don't want to be piercing the wire insulation to measure voltage with the plug still connected.

You may try this first: Disconnect the wheel speed sensor wire harness and check for damaged/dirty/contaminated/deformed pins at both ends. You wouldn't be the first guy to experience this code from something as simple as a problem with the wheel speed sensor harness connector pins. Spray some contact cleaner in each of the two connector plugs, re-plug and see if the code returns. The wheel harness is only approx 15" -18" long.

OneFasTT997

Ok, I tested it. By putting a voltage meter with one pin to the sensor and the other to ground I saw 0v on the left rear and 1v on the right rear with the wheels stopped. I then put the car in drive and the left rear read .4v and the right read 1.4v. Does this confirm it is not working?

lionelhutz

There should be 2 pins on the sensor and you measure between them, not from 1 pin to ground.

OneFasTT997

When I did it that was I only saw a little bit of voltage when the wheel started spinning and when it stopped. I tried both sides with the same result. This was with the car in gear and the wheels spinning at 10mph.

fmvette9

I got a similar code every time I backed up. I swapped the left and right wire harness, and the code followed the harness. I then sprayed the harness connectors with electrical contact cleaner, which fixed it. A mechanic said there are far more faulty wire harness / connector issues than faulty hubs.

OneFasTT997

I was measuring DC. Strange thing is that I get 1v on the right side and then 1.5 with speed using DC and ground. I will try with AC but it seems like a coincidence.

OneFasTT997

I hooked the digital meter up to it on AC this time and got .1 to .4 volts depending on speed. Both sides measured the same. I will spray the contacts and see if that helps. This shouldn't be a EBCM issue right?

Bill Curlee

Your problem is more than likely BAD FEMALE PINS!!!!!

DELPHI/DELCO female pins in out C5s SUCK

They get spread and make very poor or NO contact with the male pin in the connectors. You can use a metal pick and bend the little tang in the female pin back up to make proper contact with the male pin. Same problem with the DOOR HARNESS Connectors.

The proper way to test the female pins is to use a male pin and do a PIN PULL TEST. If it has grip / resistance pushing in and pulling the male pin out, its good.

Here is an example of a bad female pin in a front WSS jumper harness: Compare it to the new connector!

New on the LEFT,,, BAD on the right:

OneFasTT997

Mine looks sort of like the bad one but not quite as bad. Track day next weekend so I guess I will find out then! Thanks for the help!