Update. The ABS code is C0045. I will keep you posted it is at shop. They say wiring to sensor is good. I will know more on Tuesday.

 

Signal good, replace sensor.

 

As hummerz advises, but the sensors seem very expensive, is there anyway to test to be 100% positive?

 

 

... was just watching the exact same video..

 

Update...on C0045

Installed new rear driver speed sensor from Autozone....NO CHANGE

Wiring was tested by shop. There is power to and from module. Said there is 500 ohms.

Sent ABS Module to UPFIX and had it rebuilt. NO CHANGE

Ordered another Sensor from Amazon..Should be here tomorrow.

Should I clean the grounds? They look original.

Please help!

 

good luck with the amazon sensor. there are many sub par inferior or straight fake parts on there.

 

Yes we will see. I just want to see if there is a change. I only got it because it is easier to return if it doesnt work

 

According to GM, a disconnected rear wheel sensor should measure between 4500-5400 Ohms, so you can check your old one, the installed one, and the new amazon one. If you spin the wheel (sensor disconnected) you should measure 100mV A/C across it (not sure how easy that is to spin a rear wheel)

Disconnect the EBCM and measure the continuity between Pins 20 & 21 in the harness connector, you be able to measure the same resistance value and A/C mV value as above. Leave the meter connected on ohms and flex the body harness along it's entire route all the way to the wheel, also flex the wheel connecter and its cables. Any variations in resistance indicate either a problem in the harness or the wheel connector. A classic cable fault may only exhibit small fluctuations during flexing as the movement disturbs the cable strands, yet when left "quiet" may go open circuit as current flows and temperature changes. The small fluctuations are the "give away"

I'm not sure if a sensor connects through it's body to the chassis (just check a spare) if it doesn't then the wires in the EBCM connector should connect to nowhere else. Check the continuity of Pins 20 7 21 to every other pin in the EBCM connector, they should all read open circuit i.e. as if the meter was unplugged. If the sensor does go to ground unplug it and do the same tests.

As a double check compare these values against the rear right wheel (i.e. Pins 1 & 2) the results should be very similar.

At the EBCM connector, if you can measure the correct resistance (and its rock steady!) a similar A/C voltage and no connection (leakage) to any other place, then things point back to the EBCM.

It's possible at high speeds the sensor simply isn't registering, how that can be is hard to say, I find no references to this phenomenon other than wiring problems, water ingress or possibly contamination in the rear wheel itself (rust maybe? - seems unlikely)

According to GM you need to clear the scan codes to clear the DTC and MIL.

🤞🤞🤞

 

Yes, verify the reluctor.