Hey Gus...

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#1
My son has a 2006 Chevy Equinox,3.4....We are getting a code C0036....right front wheel speed sensor circuit range/performance......The TC and the ABS light are on.....I took both front sensors out and cleaned them and they both ohmed out at about 1400 ohms...I think ...I thought I read they were good between 700 and 1700 or something like that...not sure....anyway cleaned them and reset the code,he drove it about 200 miles and thought it was fixed....His wife drove it the next day and both lights came on....Same code and I reset it again and they came right back on...Thanks for any help you can give me on this....Jim
 
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#2
Could step in until Gus wakes up.



Can't quite make out if this is a two pin, magnetic coil pickup, or a three pin, Hall Effect pickup that would determine if the resistance reading is valid or not. Typically on the RF, with that short pigtail on the sensor, find an extension cable with another connector that can give problems, before it enters the main ABS module cable. With the magnetic pickup two pin, like to measure the resistance right at the ABS module.

But resistance only shows continuity, if good, will pass the static test, but then the ABS is looking for pulses for the dynamic test, meaning the ABS light will go off when you first turn on the ignition switch, but will come on after the vehicle is moving for the dynamic test.

Have measured good resistance, but many turns of an extremely fine wire in these things. Just a few shorted turns and a scope shows a very low or marginal output pulse.

Did read ABS decreases accidents by 8%, if such a safety device is required now on all vehicles, should carry a lifetime warranty. Dream on.

They also claim ABS does not affect normal service brakes. How can they say that when those modulating valve interrupt fluid flow to the cylinders/calipers? If one sticks closed, no brakes on that wheel, if all four stick closed, no brakes period! Completely worthless on glare ice during an ice rain.
 

Gus

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#3
Thought C0036 was LF?

Does this happen to come on mainly when slowing down? Since you pulled them out, did you sand down the surface the sensor mates with? There was a TSB, not sure if it was for the Equinox, that rust could build up under the sensor, causing a gap increase, that caused the code when slowing down at about 10-20 mph....

Not sure if the sensors are the same part number and are interchangeable....if they were, I would have swapped sides with them, and then if the same code came back, could be the wire harness to the sensor.....if a new code for the other side, you know it's the sensor....
 
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#4
I see c0036 as Left front, it is a 2 wire sensor, moving the harness check for an open or changing reading,wire issue or connector. I am off to the books for a confirmation of that OHM spec - seams a little higher thsm I remember, you did not say if both were the same reading.
 
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#5
Jim...An ohms check at the ABS module connector might be a good idea; to check the entire circuit.

Don't forget that the tone wheel could be the cause. Rust, cracks, chips, wheel bearing.
 
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#6
I don't have the vehicle here now. but...NickD...yes...it is a 2 pin connector...Gus...Yes...C0036 does show LF on Alldata and RF on my scanner...that is why I cleaned both of them...The sensore have the same part# from Autozone...but looking at Alldata the front sensor says comes as part of the hub...Kev...yes they both had the same reading....Danica...the tone wheel is not exposed to the weather...the sensor sits in a hole in the hub...I looked at the tone ring and it looked shiny ...except for some grease on it...I sprayed brake cleaner in it and blew air in it to dry it out...I will try swapping sides with the sensors and see if it does anything...thanks for the help...Jim
 

Gus

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#7
The sensors should look like NICKD's picture and are not part of the hub...
 
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#8
Yes it does Gus....I was just saying the dealer wants to sell the sensor with the hub....I am not sure about the light coming on when he slows down, but I will ask....also I will swap the sensors out and see if the code changes....thanks....Jim
 
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#9
1,400 ohms is an incredible amount of resistance for a coil of wire, extremely fine. Have an electronic shorted coil tester that shows shorted turns, drastic when dealing when dealing with a pickup coil like this for eating up the voltage output, wound on a small permanent magnet. Just saying resistance only shows an open or a short. One I pulled apart had water leaking in that froze compressing this very fine tiny coil of wire. But embedded in epoxy, and certainly not repairable.

Wonder what automotive electronic troubleshooting has against using an oscilloscope, don't know whether to laugh or cry when I read, solid state, do not test. Of course they are referring to an ohmmeter, of course you can't test pulsed outputs with an ohmmeter. In the lab, we constantly use scopes, have a logic analyzer and also an HP with a printer output and was constantly emailing waveforms.

Rockauto.com shows a price range of 30 to 70 bucks for this sensor, says fronts and rears are the same for either side, but the fronts and the rears are different from each other. Was surprised to see the Delco units closer to the 30 buck side. Ha, print this out to take to my dealer or auto supply store, can you match it? Dealer couldn't even come close to that 30 buck price I paid for that OE master cylinder for my DeVille. So waited a couple of days to save a couple of hundred bucks. Used another internet source to save over 500 bucks on the same cat back exhaust system for my Supra than what my Toyota dealer wanted. Volvo for my stern drive is really insane for parts, 300 bucks for a U-Joint, doesn't even have a name on it or a zerk fitting. Got a much better on Made in the USA from NAPA for 15 bucks. No wonder why on that boating board I joined guys were paying 1,800 bucks to have these U-Joints changed. Took me five hours and 30 bucks to do the same thing.

Its crazy, if the parts were made decent in the first place, wouldn't even have this problem, but I have seen my own stuff with a manufacturing price of 90 cents at a Honda dealer selling for 150 bucks. In bidding against China that started in around 1993, was just talking about a fraction of a cent difference in unit cost. Our biggest enemy was our own IRS, do meet quoted prices had to run a huge production run at once, customer just wanted JIT delivery, they don't want to fight with the IRS either. IRS valued inventory at what we sold it before, stupid, we didn't even make that profit yet and you can't pay them with voltage regulators, main rectifier assemblies, or ignition modules, want cold hard cash. I can't tell you how much I hate our government, China doesn't have this problem. If you are looking for traitors to this country, look no further than Washington D.C. This tax is what killed us, giving China the edge!!!

This is on the supplier end of automotive parts, you can appreciate the shock when dealing on the consumer end. We also had frequent visits from the EPA, OSHA, and the ERA, with the latter, couldn't hire people based on qualifications, had to be based on age, sex, and race, talk about having your hands tied behind your back.

Not really off topic as what we have to pay for parts is very much a part of this board. Looked up Carquest and NAPA in our property tax website, they have to sell a ton of stuff just to pay that bill and for a bunch of lazy ass government workers. God, we are getting screwed. Wasn't this was in the 50's, 60's, and early 70's when this country was great.
 
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#10
Just thought I would update this with a fix...I swapped the 2 sensors and the same code came back...Ordered a new wire that connects to the sensor wire and goes in through the fender area....the wire was about 12 in. long...anyway after changing that the code has not come back and it is driving fine...thanks for the help...Jim