Abs Sensor

[j.e.1975]

My Abs engages just before the vehical comes to a stop. I need to know the proper ohm and votage readings for the front and rear sensors. I tested the fronts and got the same readings side to side. I don't have the ABS light on so does that mean the sensors are still good. Also where is the rear sensor located. I tried to do a search but have come up with nothing but to clean the sensors, I would like determine which one or is it both.

 

Thanks

John

[Wires]

My Abs engages just before the vehical comes to a stop. I need to know the proper ohm and votage readings for the front and rear sensors. I tested the fronts and got the same readings side to side. I don't have the ABS light on so does that mean the sensors are still good. Also where is the rear sensor located. I tried to do a search but have come up with nothing but to clean the sensors, I would like determine which one or is it both.

 

Thanks

John

 

 

Can't help you with the readings, but the rear sensor is located in the tranny (runs the speedometer + ABS).

 

What year of truck? The GMT800's were nortorious for having the ABS module fail. I started getting ABS lights before it fully died.

 

I'd pull the sensors out and clean them. That's probably your issue. They have a magnet in them, and sometimes get filled up with filings, which gives a bad signal to the ABS module.

[j.e.1975]

It's an 05 Yukon. I tested each front sensor for ohm and volts and I get the same reading on both sides. The speedo works fine so I assume the rear sensor is ok. I have already tried to remove the right side and cracked the housing. I tightened it back down and nothing changed, still no ABS light. I was hoping to pin piont which side so I could try and avoid replacing both if it's not needed. The next step is to compare the readings to my 03 Silverado.

 

Thanks

John

[minibike132]

If you cracked one it's junk, replace it. This issue is always (well almost, like 99.99% of the time). You already broke the right side so replace it and see if it goes away. Breaking the sensor will increase the gap, and expose the wires in the sensor to corrosion.

 

This problem isn't usually because of an electrical failure, it is because of an air gap issue between the sensor and the reluctor. The only real way to pin point it is by looking at some data on a fast scanner. No matter how fast the scanner is you usually can't tell which one it is by looking at wheel speed data because the EBCM stops reporting wheel speed over the data line @ 3mph. You have to watch what the isolate and dump valves are doing to figure out which side is the issue.

 

Bottom line is unless you know someone with a great scanner you are not going to pin point it.

[j.e.1975]

I did the same test on my 03 as I did to the Yukon. Ohm reading is the same but the voltage reading is alot higher from the 03. I know the craked sensor needs replaced. I was hoping I could confirm it was the sensors before I crack the other side only to find out that two new sensors didn't fix it. How do you remove a sensor when the top has separated form the body within the wheel hub.

 

Thanks

John

[minibike132]

I did the same test on my 03 as I did to the Yukon. Ohm reading is the same but the voltage reading is alot higher from the 03. I know the craked sensor needs replaced. I was hoping I could confirm it was the sensors before I crack the other side only to find out that two new sensors didn't fix it. How do you remove a sensor when the top has separated form the body within the wheel hub.

 

Thanks

John

 

I don't have a magic answer for that. Usually when the sensor cracks it cracks right at the seal. Then you can use a seal pick to get the seal out and work the rest of the sensor out. It's the seal that keeps it in so tight so once that is out of the way the rest can usually be worked out.

[j.e.1975]

I bought two new sensors through AcDelco, $55.00 each Canadian. Replaced the driver side. You could see the rust under the body of the sensor. The sensor broke getting it out. New sensor fixed the probelm and the right side sensor is ok. The right side is cracked inside so we'll see how long it lasts.

 

Thanks for the replies

John