C0221 Right Front wheel speed sensor

Boomer

Hero Member
Joined
Mar 14, 2007
Messages
278
Likes
0
Points
16
#1
Make
Chevrolet
Model
S10 pickup 4x4
Year
2002
Miles
148,000
Engine
4.3
I have this code. I remember having this problem and replacing this sensor a couple of years or so ago. I recall testing it with my meter while spinning the wheel. I can't remember the specs I should be looking for. I erased this code with my Actron scanner. When I restarted the truck, it came right back without moving. Is this thing sending a voltage or ground signal to it so that it can read it without the wheel moving?
 

nickb2

Wrench. Diagnostic Tech.
Joined
Nov 22, 2008
Messages
8,388
Likes
126
Points
63
Location
St-Hyacinthe, Quebec, Canada
#5
Damn, posted while drunk again. So I will try to correct myself.

Spec should be about 350 AC millivolts when the sensor is clean.

I read that you got the code with an actron code reader, is that thing capable of giving you that data? If not, you can check with your trusty old DVM.

There is a TSB for this, and mostly, a very important one to heed as I have done literally thousands of these. Ok, maybe not thousand's but over many hundred. Thats what 27yrs in this trade gets you.

Be sure to clean all surface mounts, but when you do that, be sure to plug the sensor hole to make sure no rust falls in there.

I am assuming you have a ABS light on. Yes? Can you post the code you got with that actron ABS capable code reader? These types of sensors don't usually fail at the sensor itself, mostly it will be a wiring harness that has rubbed through. Bad design by GM. When I install a new one, I always make sure the loomex has not rubbed through. If you see any of the wiring harness that has rubbed through, which is classic, you can solder that no problem. But sometimes the wire break right at the sensor, then you need a new one. But if you don't clean the surface mount, you may get ABS activation at low speed.

I hope this response was better than my last one, I think I was tits up in beer, dancing with a few girls as I had a party at my house. It was fun, but I should refrain from trying to be serious here when I have done the canadian beer thing.

 

Boomer

Hero Member
Joined
Mar 14, 2007
Messages
278
Likes
0
Points
16
#6
Damn, posted while drunk again. So I will try to correct myself.

Spec should be about 350 AC millivolts when the sensor is clean.

I read that you got the code with an actron code reader, is that thing capable of giving you that data? If not, you can check with your trusty old DVM.

There is a TSB for this, and mostly, a very important one to heed as I have done literally thousands of these. Ok, maybe not thousand's but over many hundred. Thats what 27yrs in this trade gets you.

Be sure to clean all surface mounts, but when you do that, be sure to plug the sensor hole to make sure no rust falls in there.

I am assuming you have a ABS light on. Yes? Can you post the code you got with that actron ABS capable code reader?

C0221 Yeah, I was pretty confused with those music videos you posted Nick :cool:
 

nickb2

Wrench. Diagnostic Tech.
Joined
Nov 22, 2008
Messages
8,388
Likes
126
Points
63
Location
St-Hyacinthe, Quebec, Canada
#7
I have posted the trouble charts, but it essentially said what I wrote earlier, with my now sober brain. The saltwater is an old trick, I always have a spray bottle on hand, helps to find the short in the harness.

Again, sorry for the posting whilst drunk, but I must say, the hangover was worth it. Fun to see a few girls dancing to abba on my living room floor. Kind of got kinky there for a moment, had to throw the other girl out, my GF would never got over that if it went to far. :eek:
 

Attachments

Boomer

Hero Member
Joined
Mar 14, 2007
Messages
278
Likes
0
Points
16
#8
Thanks Nick. I think that is the chart I used a few years ago. I get up to 750mV when spinning the wheel as fast as I could. The sensor sits with 962 ohms of resistance. I’ve moved to step 6 but, I have no idea what the pinout is. I don’t see any shorts to ground. Checking for shorts to voltage only one pin has 0.3 volts so, that looks ok. As far as open and shorted together, it’s a guessing game when I don’t have the pins I’m looking for
 

Attachments

Boomer

Hero Member
Joined
Mar 14, 2007
Messages
278
Likes
0
Points
16
#9
Thanks Nick. I think that is the chart I used a few years ago. I get up to 750mV when spinning the wheel as fast as I could. The sensor sits with 962 ohms of resistance. I’ve moved to step 6 but, I have no idea what the pinout is. I don’t see any shorts to ground. Checking for shorts to voltage only one pin has 0.3 volts so, that looks ok. As far as open and shorted together, it’s a guessing game when I don’t have the pins I’m looking for
Ok, I finally kicked my brain into gear and did a continuity check from the other end of the harness to the ECBM. I’ve found the 2 pins. They only have about 0.3 ohms resistance so, the wiring seems ok. I hope it’s not the module because I’m sure that’s not cheap
 

nickb2

Wrench. Diagnostic Tech.
Joined
Nov 22, 2008
Messages
8,388
Likes
126
Points
63
Location
St-Hyacinthe, Quebec, Canada
#10
In that case, only two option here. If no joy with a new sensor, then it can only be the EBCM or you did not follow the flow chart by omitting a step. Or in case of the improbable, your dvm is not correct. Which one is it? Who knows.

I like to say this here often.

Sherlock Holmes theory


when you have eliminated the impossible, whatever remains, however improbable, must be the truth
 

Boomer

Hero Member
Joined
Mar 14, 2007
Messages
278
Likes
0
Points
16
#12
I took the tire off and found a wire broken going to the sensor right where it clips to the vehicle. I stripped the rubber coating off and spliced in a short jumper wire. The light went off after I started driving. I think there was enough copper making contact when I spun the wheel during testing earlier to make it test ok. Now I have a stopgap until I install a replacement sensor.
 

jd

Hero Member
Joined
Jan 14, 2007
Messages
502
Likes
21
Points
18
#15
I love being able to do it that way too! I hate throwing parts at something. So much more satisfying. :)
Me Likewise!
I've been able to fix things that I didn't actually understand, but simply looking them over and noticing something "out of place."

It seems that even this modern age of Sensors, Codes and Scanners, that some systems still do a self test on every drive cycle and actually turn the Light Off if the test passes. I forgot to plug the front sensors back in on an axle replacement job. Started it up and that ABS light stayed on. When I re-connected, still stayed on. Then I drove it, and after a hundred yards or so, it went out. Been normal since. New Sensor oughta do it.