PontiacBonnevilleClub.com

UPDATE (just after 6 months):

ABS ANTI LOCK light back on.

Had bad rotors that were replaced together with new pads, serviced caliper pin boots and lubes caliper, that is now as good as new.

ABS problem persisted afterwords.

No bearing humming noises.

Did WSS test on all 4 wheels. Here are findings:

Left Front:
Ignition on, current supply to WSS: 4.75
Resistance at idle from WSS: 1.09kOhm
Resistance at rotating from WSS, in kOhms:varying range 15; 18; 19; 10.
VAC at rotating at about 900 rpm: 1.3 to 1.3V

Right Front:
Ignition on, current supply to WSS: 4.76
Resistance at idle from WSS: 1.07kOhm
Resistance at rotating from WSS, in kOhms:varying range 8; 6; 5; 11; 10; 13
VAC at rotating at about 1300 rpm: 2.7 at about 700 rpm to 0.9 V, average 1.6V (value may be higher due to higher rpm).

Left Rear:
Ignition on, current supply to WSS: 4.79
Resistance at idle from WSS: 1.07kOhm
Resistance at rotating from WSS, in kOhms:varying range 1.1kOhm.
VAC at rotating: 0.1V
VDC at rotating: 0.2; 0.3; 0.8 V

Right Rear:
Ignition on, current supply to WSS: 4.75
Resistance at idle from WSS: 1.1kOhm
Resistance at rotating from WSS, in kOhms:varying range 1.1kOhm.
VAC at rotating: 0.2V
VDC at rotating: 0.1; 0.2; 0.7 V

Trying to find the one that sinned and replace. Kind of hard to identify. Any ideas?

Above is testing data, maybe bit redneck but with all knowledge of the club maybe we could get it figured out.

Thanks.

L&B

I would be taking a shot in the dark, both rears sensors are out. I think 0.5VAC minimum is needed to be generated by the sensor. I'd have to check my books later to verify.

Resistance across the coil (not with wheel rotating), VAC generated at the same speed, are what is needed to determine if a WSS is/isn't working. I'm failry certain the CSMs tell you to turn the tire by hand when measuring the AC voltage too, so should be able to get fairly repeatable results.

Don't rule out, 90% of the time it's an issue with one of the wires. Do a continuity check on the wires.

Does the ABS light come on and stay on as soon as you start the car or when you start moving?

Its possible that the ABS/Trac pump or EBTCM has bit the dust..

would be good to pull the ABS codes to be sure tho..

Thanks MattStrike,

I turned the rear bearing with the drill and brush wire disc, after I removed the drum, and hoocked the spare wire commection onto WSS. Both tested at the same speed.

When I wrote "resistance at idle", I meant when the hub was not rotating. These values are quite constant Rear left 1.07 and Rear Riright 1.1 kOhms.

When I wrote supply current on WSS in VAC, that was what current come to WSS from the system/computer/abs module.

How should/coild I do continuity test? You mean on the short wire that goes into the rear bearing?

Thanks,

L&B.

Thanks Jrs3800,

ABS light used to come on just after few feet of driving.

Now it is on right as you start the car.

Were is ABS/Trac pump located and what is the meaning of EBTCM and how to remove that dust?

Thanks,

L&B.

PS: I have no access to ABS scanner, and do not opt to go to the dealers. Is there a way to figgure the way to find the problem in other way? Please note that my front discs were warpêd and when breaking I felt as my foot on the break is pulsing, when applying break on slow speeds. On high speeds even rougher. So I have changed discs and and pads on the front this passed weeekend.

Yes, the short wires that go between the body and the sensor. Of course, I forgot to look at the CSM spec for the sensor for the field test.

Continuity test: You have a DMM? If so, it may have a diode tester, mine (radio shack $30) beeps when you touch the probes together. One probe on either end of a wire will beep if the wire is not broken. Another way (DMM only) is to put it on DC volts mode, notice the readout will show a 'floating' voltage? Touch the probes together and it will should zero out. So it should also zero out if you touch either end of a good wire.

If you have access to an autozone, their free scanner maybe able to read the ABS codes.

The ABS pump will be below the Air Box, But this may not be the problem so don't replace it... Yet...

There is EBTCM( Electronic Brake Traction Control Module ) EBCM( Electronic Brake Control Module )

I also agree, see if Autozone or the like can read ABS codes..

Thanks Jrs3800 and MattStrike,

MattStrike could you please check your books to verify if more then 0.5VAC is needed to be generated by sensor?

MattStrike, what do you mean by saying there are wires that go between body and the sensor?

What I saw the connector to sensor has just 2 wires. Are these one of them? One is white another is black.

Are one of these that I need to test for continuity? and where does it connect to the body? Is that like a ground wire or something?

Thanks a lot guys, I hope to get this figured out soon and back on track asap, but not sure how quick could I get to free Autozone for scanning or similar. This is unheard of in Canada. But I will check. This is why I more rely on simple testing.

L&B

What is CSM spec for the sensor for the field test?

L&B

According to CSM:
Sensor wire is the wire between the body harness and the WSS, it is about a foot long, and hangs in the brackets on the knuckle and strut. It is exposed to everything the tires kick up, and is one of the spots that can oxidize easily. Also, where the wire goes into the wheel hub is another common break point.

From the CSM;
Spin the wheel as fast as you can by hand, AC volts must be greater than 0.1V (100mV).

So I was off. But, if you can spin each wheel the same speed, the voltage should read the same across the board.

Thanks MattStrike,

I have noticed as I start vehicle in the morning ANTI LOCK light is off, but it takes me just to turn drive on and to move/drive just half a feet the light comes on. What would that suggest? Would that suggest ABS pump ok?

I have already did the test of spinning the wheels and measuring VAC coming out of WSS. Here are results:

Left Rear:
VAC at rotating: 0.1V
VDC at rotating: 0.2; 0.3; 0.8 V

Right Rear:
VAC at rotating: 0.2V
VDC at rotating: 0.1; 0.2; 0.7 V

I removed rear drum and used round wire brush on the drill that made the spinning.

I have checked on RockAuto and it seems that rear WSS is available as separate part. So since my rear bearing are not noisy, how could I be 100% sure that it is WSS that is faulty. From above test though it seems like Left rear is to blame.

I will get more precise voltmeter and will test again.

Any trick how to test, the WSS itself to be 100% sure it is faulty? Is there a good way to get one at SCRAP yard and test with it?

Thanks guys,

L&B

I would use the meter to see what some junkyard WSS show.

The light not coming on until you are moving makes me think it's got to be a sensor and not the wiring. How many speeds does your drill have? You should make a table of each speed vs the VAC. Put the trans in neutral, you should be able to spin the fronts at the same speeds as the rear and be able to correlate the differences. You'd be looking for a sensor that reads higher or lower than the rest.


Last I checked, the WSS is integrated in the wheel bearing. If the sensor is bad you can press it off and press on another once the wheel bearing is removed, but you can't find these parts 'new' individually. But they are interchangable with the non-ABS vehicles, so maybe it can be saved/sold for use elsewhere if you have to replace it?

Just back from Mechanics Garage.

Replaced belt-tensioner and muffler, oil change + regular inspection.

During inspection found that front right bearing hums and is noisy. Wow to my surprise my both front bearings are less then 1 year old. How disappointing with Raybestos. Never again for Raybestos, I have used 4 and all 4 failed in less then a year or less in a 6 month. Can you believe it!?

While there did ABS scan and found these codes. After codes cleared rescanned and found same codes:

C1211 ABS Outlet Valve Coil RF Circuit Open
C1213 ABS Outlet Valve Coil RF Circuit Short To Ground
C1214 ABS Inlet Valve Coil RF Circuit Failure
C1216 ABS Inlet Valve Coil RF Circuit Short To Battery
C1218 Lamp ABS Warning Output Circuit Failure

I think all problems are showing in RF bring and it actually hums.

You comments please.

Also mechanic found front left ball joint is getting loose. Any feedback on that, is it hear of, how long do they last how dangerous it could be? Do I need to do wheel alignment after ball joint is changed? I heard original is on the weld or rivet spots, but replacement would be on the threaded nuts and bolts.

Thanks and awaiting for your feedback.

L&B

I found a broken wire on the left reat abs harness. It broke right at the connector were all four wires hook up. How do I push the pin out of the connector to get this wired back up? abs lites are on im sure this is the reason why.

I sell that harness for $20 if you want to make life easier.

UPDATE:

Replaced right bearing that not just hummed but also was getting loose.

After that, test driven.

All was silent and ABS ANTILOCK light is gonne.

Have checked the left bearing and I was able to tighten it with axle nut.

ONLY NEW SLIGHT PROBLEM: at speeds nearly 0, when breaking, my ABS rattles (makes rattling noise) seems like it thinks that one wheel is slipping. At high speeds no problem whatsoever.

I tend to think that is due to failing ABS sensor on the front LEFT bearing. Well as it is silent and not loose I will drive on it untill it goes and then as I replace it we will see how my diagnosis was.

Thanks to all for your help, of course your sugestions and comments are always welcome.

Thanks,
Larry

Don't think I will spend this much time on my ABS, light comes on intermittently.
Anyone know if Autozone can read ABS codes?