2000 Silverado ABS recalls, help ????

Hello guys, So, my 2000 silv with 4.8,5 speed,short bed short wheelbase, 4x4, with285/75 16 tires, and 51,000 miles, started something new recently and i need help. One or maybe both front wheels are having intermitant abs triggering probs. Once i start braking with light to moderate brake pedal and reach low speed, comming to a full stop,my front wheels or wheel( feels like passenger front wheel) triggers and cycles on dry max grip or any grip conditions. So, instead of my truck coming to a stop, it CONTINUE'S, to move forward. This abs event cycles for half to two secounds and then shuts off, and finally the truck stops. This is getting unnerving to say the least. It will trigger when all other wheels seem to have grip even in snow, so this isnt a loss of grip issue. I called the dealer today and got the usual, and I Quote" No, no recalls, is it in warranty? if not? We'll have to do some diagnostic. Might be a wheel hub problem, Cant be a wheel speed sensor problem!") His last statement is what bothered me the most. This truck has not had a brake service on front axill yet, and still has one half pads left. And no, its not under warranty, and there has never been an ABS light come on at all. Should i pay to have diagnostic done? Can i pull abs fuses ( and where are they) and see if a hub is gooffing up? I have not had any problems with abnormal wheel movement, everything runs true down the road. Money is tight, so any help would be appreciated.

Merlin, you out there?

Jack

I have the exact same problem with a 36,000 mile 2000 Silverado 5.3 automatic. I read a post where it was a rusty speed sensor causing the problem and cleaning fixed it. I have never driven anything where the brakes just start buzzing and stop working. I don't get any warning lights or Service Engine Soon. If it's a speed sensor can they just be replaced, how much are they and can I do it myself? Is there a manual that shows how to do it? I'm going to do some checking and if I turn up anything I'll let you know.
Sonny

Are you looking for GMMerlin...I heard it knows what he's doing.

Yes, That is who i was speaking of GMMerlin. hope he will see this. Any ways thanks for the get back and let me know what you find. It would be nice to find out it was somthing i could easily clean to fix this. Giving my dealer the truck to do unspecified diagnostic is worring. GMMerlin can get into GM data bases so his help is genuine, that and he being a GM master teck helps. Jack

Hey guys,

I had the same problem on my 99 Silverado. I pulled out the front wheel sensors, cleaned under them, put them back in and the problem was solved. I think it has something to do with rust moving the sensor too far away from the hub. I hooked up a volt meter, measuring volts AC, while spinning the hub. You should read more than 250 mV, I was getting ~110. After cleaning them I was reading over 400 mV and the problem was gone. Hope this helps!

sparhawk56

I've had similar problems with my ABS. Actually, the ABS pump is all messed up. The garage quoted me $800 for the part and $100 to put it in. I called Chevy, they say they've had plenty of people call about it but they havent issued a recall. Some one has to get their attention and let them know this is GOT to get recalled. There are just to many ABS problems on the silveradoes. I called.

Thanks for the get back. Is this somthing i can do with the wheel on? where is the senser? Soon as it warms up around here,( negative 5 tonight i'll attemt it i guess. Thanks, Jack

You have to take the wheel off to get to the sensor. I believe the connection is near the top balljoint, it should be the only wire in the area. I used to have the service bulletin printed out but can't find it.

sparhawk56

Myself (97 z71, 5.7L ex.cab) and my friend (01 z71 5.3L ex. cab) are both suffering the same problem, his is more pronounced with the abs pump kicking in. mine often just gives a sinking pedal feeling, ocassionaly with abs noise. I have checked the front sensors and their ohm readings are 833 & 840 (suposidly they are to be 700-1400). next step will be to try to get at the sensors and remove & clean them. perhaps the exciter ring also.
Inquired at dealer about sensors and depending on the model / year the sensor for most vehicles is an integral part of the hub assembly, according to them, a $600 cdn part. Yikes!
We shall see what happens.

The resistance isn't the measurement you want for this. While spinning the hub by hand look at the Voltage AC. This will tell you the interaction between the exciter ring and the sensor. I believe it's supposed to be above 250 mV, mine were 100-110 before I cleaned them, over 400 after.

You can get a seperate sensor without the hub, I broke one pulling it out and had to get a new one, about $100 US.

Hope this helps!

Surface rusting of the hub assembly forces the sensor away from the tone ring causing the voltage drop. This voltage drop is sufficient to cause ABS activation at low speeds; but not sufficient to trigger the ABS warning lamp.

Clean the wheel sensor, hub casting and their mating surfaces. Then reassemble.

After the repair and the ABS system has been road tested to verify proper operation; Coat the hub and sensor with several layers of rubberized undercoating spray to prevent the problem from occuring again.

Sorry I havent been cruising the boards here lately, but from the looks of it, you are on the right path.
Here is a copy of a GM bulletin that applies to you concerns of low speed ABS activation.
Someone else mentioned the problem of the ABS pump running all the time...that is a separate issue caused by an internal failure of the ABS module....there are NO RECALLS on these issues at this time.
On the subject of the ABS pump run on, there is a gentleman on these boards..I believe his name is Ken Spragg of circuit solutions that had a fix for this...If someone can get in touch with him and have him contact me, it would be greatly appriciated.



here is the bulletin

Antilock Brake (ABS) Activation At Low Speeds (Clean Wheel Speed Sensor Mounting Surface) #03-05-25-007 - (09/29/2003)
Antilock Brake (ABS) Activation At Low Speeds (Clean Wheel Speed Sensor Mounting Surface)
2002-2004 Cadillac Escalade, Escalade EXT

2003-2004 Cadillac Escalade ESV

1999-2004 Chevrolet Silverado

2001-2004 Chevrolet Suburban, Tahoe

2002-2004 Chevrolet Avalanche

2003-2004 Chevrolet Express

1999-2004 GMC Sierra

2001-2004 GMC Yukon, Yukon XL

2003-2004 GMC Savana

2003-2004 HUMMER H2

Condition
Some customers may comment on ABS activation at low speeds, usually below 8 km/h (5 mph). Upon investigation, the technician will find no DTCs set.

Cause
The cause of this condition may be an increased air gap between the wheel speed sensor and the hub reluctor ring due to rust and debris built up on the sensor mounting surface.

Correction
Measure AC voltage and clean the wheel speed sensor mounting surfaces.

Raise and support the vehicle. Refer to Lifting and Jacking the Vehicle in the General Information sub-section of the Service Manual (SI Document ID #899664).
Disconnect both the front wheel speed sensor (WSS) connectors at the frame and harness.
Place a Digital Volt Meter (DVM) across the terminals of each WSS connector.
Rotate the wheel clockwise approximately one revolution per second. The minimum reading should be at least 350 ACmV's. If the reading is less than 350 ACmV's, remove the wheel speed sensor. Refer to the applicable Wheel Speed Sensor Replacement procedure in the ABS sub-section of the Service Manual. Plug the WSS bore in order to prevent debris from falling into the hub during service.
Clean the WSS mounting surface on the hub to remove any rust or corrosion using a wire brush, or equivalent.

Important
Make sure that the sensor sits flat on the hub. Check the sensor flange against a straight edge to ensure flatness. If the sensor flange is distorted, replace the sensor.


Apply a thin layer of bearing grease to the hub surface and sensor O-ring prior to sensor installation. Use ONLY Wheel Bearing Lubricant, P/N 01051344 (Canadian P/N 993037).
Install either the original sensor or a new one in the hub. Ensure that the sensor is seated flush against the hub. Refer to the applicable Wheel Speed Sensor Replacement procedure in the ABS sub-section of the Service Manual.
Place the DVM across the sensor terminals and recheck the voltage while rotating the wheel. The voltage should now read at least 350 ACmV's.

Hi GMMerlin,

I am the individual from Circuit Solutions that rebuilds the EBCM modules with the pump run condition as well as other EBCM problems. I also rebuild as the troublesome 4X4 switch cluster for the ATC equipped vehicles.

Hi GMMerlin,

I am the individual from Circuit Solutions that rebuilds the EBCM modules with the pump run condition as well as other EBCM problems. I also rebuild as the troublesome 4X4 switch cluster for the ATC equipped vehicles.

Gavin,
I appologize for getting your name wrong..thank you for responding.
I sent you a PM.
Thanks
Merlin

Thanks for the info GMMerlin. I just got finished cleanning the wheel speed sensors on my 2001 Silverado, and they work great! It's better than spending the $500 the dealership wanted me to spend. I got my info on how to do it by GMMerlin's post and the Haynes Repair Manual.
As a new member, thanks alot for the great site and posts. I am finding alot of useful info to help me.

Has there been a recall for anti lock brake issues like this for the 2001 silverado? Mine is doing the exact same thing.

Has there been a recall for anti lock brake issues like this for the 2001 silverado? Mine is doing the exact same thing.

how many miles on this vehicle ? what issues do you have with the braking ?

163,000. brakes will make a moaning noise, brake pad will be completely compressed and truck will move forward another 3 - 4 feet before catching and stopping. Only happens just before complete stop.

163,000. brakes will make a moaning noise, brake pad will be completely compressed and truck will move forward another 3 - 4 feet before catching and stopping. Only happens just before complete stop.

since your over 120,ooomi I doubt you would get anything from GM.

the ABS recall was for failure of the front hub speed sensors to properly report the correct speed when the vehicle was moving under 5-10 mph.

the hubs rust up badly so much so the cheap plastic sensor gets pushed out of the hub slightly this reduces the pick up voltage to the PCM/comuputer..the the brakes will not stopthe vehicle because the ABS module will cause the brakes to pulsate rapidly.


your issue is items like calipers including the slide pins,brakes setting too tight in the caliper, rotors excessively rusted/worn..

make sure the rear brakes are also checked.

open bleed screw then push back calipers fully so that the cal piston fluid is removed.

thanks. I did have to replace a brake lining and did bleed all brakes. It has not been used in a long while and the rotors are very rusted. Will get at it in a couple weeks. Peace

thanks. I did have to replace a brake lining and did bleed all brakes. It has not been used in a long while and the rotors are very rusted. Will get at it in a couple weeks. Peace

if the rotors have surface rust only , sand the rotor surface with 120 grit sand paper in a rotational direction. then wipe down the surface with mineral spirits. If pads are good sand those as well and clean same as the rotors. then make sure the calipers slide and the piston is not binding,,,.

good luck ..

thanks, will do

Hello every one,
I have problem with my 2005 Chevy express van. Looks like similar problem that all have it. I replaced wheel sensor but it didn't help. Here is what my mechanics said when I asked him to help me. "you have to go to dealership we can't fix it. Here is info from your van computer Code CO 131 ABS/TCS System. What is that mean?
Thanks for any ideas.

Hello every one,
I have problem with my 2005 Chevy express van. Looks like similar problem that all have it. I replaced wheel sensor but it didn't help. Here is what my mechanics said when I asked him to help me. "you have to go to dealership we can't fix it. Here is info from your van computer Code CO 131 ABS/TCS System. What is that mean?
Thanks for any ideas.

what is needed is the vehicle details. also the issues you are having with the ABS.

your CO 131 DTC code is not valid as far as I can determine.

I have worked theis abs on the silverado and have had good results.

replacing the speed sensor in most cases is not the cause of ABS issues.the sensor only fails if the wires get damaged or the tech has to use excessive force to remove from the hub.

measuring the voltage of the sensor output is what is needed when determining whats going on , also the bearing assy condition etc. thats if this is the cause of your problem whivch you say is what most have with this.

the wheel hubs rusting out internal and external causes most ABS failures not the sensor itself.

Hello every one,
I have problem with my 2005 Chevy express van. Looks like similar problem that all have it. I replaced wheel sensor but it didn't help. Here is what my mechanics said when I asked him to help me. "you have to go to dealership we can't fix it. Here is info from your van computer Code CO 131 ABS/TCS System. What is that mean?
Thanks for any ideas.


if you have drum brakes and the drums are over 50,ooo mi on them your drums are worn to much. this causes the front brakes to do all the braking this will cause an inbalence in the breaking effort .

asbestos brake shoes are no longer used . therefore the drums only last on these large heavy vehicles about 40,ooomi.

WHEN THE TOP OF THE SHOE IS ONLY WORN THE DRUM IS N/G.........
IF THE DRUM HAS A GOOD SIZED RIDE ALONG THE EDGE MAKING IT DIFFICULT TO REMOVE THIS IS SAYING TOO WORN ALSO !

The C0131 is for the master cylinder pressure sensor, it is located inside the BPMV. They are difficult to diagnose because the EBCM and BPMV are bolted together, a scanner is required check readings. You can seperate the two and inspect the connector. This code can get expensive in a hurry to repair if both the EBCM and BPMV need replaced.

Here is my whole story, see if you can make any sense of it.
What was happenning first was:
1.when I start accelerate from traffic light with out pushing hard just about 5-7 mph my traction control light starts blinking and I loosing my accelerator complitly. And plus you can hear like ABS working (or some thing sounds like ABS).I can push as much or as hard as I can but van just will coast till its stops. So it can be pretty dangerous on a big intersections. So I find out if I press brake pedal fast and drop speed after that I can keep going.
2. So I went to mechanic and he told me that it's wheel abs sensor, so I order it whole assembly(hub and sensor).
3. While I was waiting for the part Traction Light came on and stays on all the time now. I replace hub/sensor but it didn't helped.
4. I'm back at the shop this time he told me this
code CO 131ABS/TCS System Master cyl. pressure sensor.
Internal fault yaw rate sensor P/N 15220053
EBCM calibration poss cause.

Here we go,that is all I have.

Answers:

I don't have drum brakes, disks all around.

2005 Chevy Express 6.0L V8

Where are this EBCM unit?

Thank you every body for your time.

Here is my whole story, see if you can make any sense of it.
What was happenning first was:
1.when I start accelerate from traffic light with out pushing hard just about 5-7 mph my traction control light starts blinking and I loosing my accelerator complitly. And plus you can hear like ABS working (or some thing sounds like ABS).I can push as much or as hard as I can but van just will coast till its stops. So it can be pretty dangerous on a big intersections. So I find out if I press brake pedal fast and drop speed after that I can keep going.
2. So I went to mechanic and he told me that it's wheel abs sensor, so I order it whole assembly(hub and sensor).
3. While I was waiting for the part Traction Light came on and stays on all the time now. I replace hub/sensor but it didn't helped.
4. I'm back at the shop this time he told me this
code CO 131ABS/TCS System Master cyl. pressure sensor.
Internal fault yaw rate sensor P/N 15220053
EBCM calibration poss cause.

Here we go,that is all I have.

Answers:

I don't have drum brakes, disks all around.

2005 Chevy Express 6.0L V8

Where are this EBCM unit?

Thank you every body for your time.

after the forum member brought out the code explaination I did some checking on this . It seems that some of these master cylinder sensors are defective. this will cause the code you got and cause your issues as explained by those that had your issue. it is possible that this may be other components but the sensor is cheap. there is a test method of this sensor. however with intermittent problems this can be hard to duplicate . I would try the master cyl sensor.

this posting was started for silverado hub rust/sensor /abs defects. your system is different you have traction control .

the rear drums on your vehicle are a problem when you notice poor braking effort and distorted front rotors. drums don't last .

this is what i have found out. simple sand on the road for traction in the winter time has magnetite in it. this will stick to the wheel and send the sensor nuts. i can drive for miles with out hitting the brakes. works good until i hit a town with a stop light. and then the brakes do not work right and i run a stop light. when i am running down the road in slush and snow is the sand sticks in the groves for the sensor. the first time it happened to me i was kinda lucky. a cop seen me and he wanted to know exactly why he had the same problem. off to the dealer we headed. there fix was to go to the wash rack clean off the groves and it worked.
the dealer even told me not to drive the truck off road or on heavy muddy gravle roads or i will need to spray out the wheels as soon as i hit the pavement. we have a lot of mines and sand around, so even on the pavement i am picking up the magnetite, even in the summer time.

this is what i have found out. simple sand on the road for traction in the winter time has magnetite in it. this will stick to the wheel and send the sensor nuts. i can drive for miles with out hitting the brakes. works good until i hit a town with a stop light. and then the brakes do not work right and i run a stop light. when i am running down the road in slush and snow is the sand sticks in the groves for the sensor. the first time it happened to me i was kinda lucky. a cop seen me and he wanted to know exactly why he had the same problem. off to the dealer we headed. there fix was to go to the wash rack clean off the groves and it worked.
the dealer even told me not to drive the truck off road or on heavy muddy gravle roads or i will need to spray out the wheels as soon as i hit the pavement. we have a lot of mines and sand around, so even on the pavement i am picking up the magnetite, even in the summer time.

if the tires pick up MUD that sticks to the tread this will cause the tires to slip when braking or starting out.

the 2000 silverado sensors are well protected from this type of exposure. on earlier GM trucks/vehicles the sensors were exposed to the elements . this would be true with the 1994 S10 pick up. this was big trouble for GM in those vehicles ..

most cases when the ABS acts up on this 2000 silverado and the many similiar vehicles now out there , its the front wheel hubs rusted out. this is easy to determine . since the sensor IS a magnet when the rust forms the sensor is quickly blinded to the encoder wheel in the hub.

with a constant sensor error the ABS LT will come on..

if the tires pick up MUD that sticks to the tread this will cause the tires to slip when braking or starting out.

the 2000 silverado sensors are well protected from this type of exposure. on earlier GM trucks/vehicles the sensors were exposed to the elements . this would be true with the 1994 S10 pick up. this was big trouble for GM in those vehicles ..

most cases when the ABS acts up on this 2000 silverado and the many similiar vehicles now out there , its the front wheel hubs rusted out. this is easy to determine . since the sensor IS a magnet when the rust forms the sensor is quickly blinded to the encoder wheel in the hub.

with a constant sensor error the ABS LT will come on..



mine was on a 2004, when it was 3 monts old, it had not been on any mud yet. just a few gravel roads and mainly highway. it did not have over 5k miles on it when it was doing it. just driving it on the heavy sanded roads made the magnetite stick to the hub so the sensor would not pick up the signal. have you ever dropped a tool in sand and when you pick it up there is a fuzz on it thats magnetite. it sticks to any thing that is metal that has a bit of magnetic property. the hubs are grate magnets its very week but makes the stuff stick.

mine was on a 2004, when it was 3 monts old, it had not been on any mud yet. just a few gravel roads and mainly highway. it did not have over 5k miles on it when it was doing it. just driving it on the heavy sanded roads made the magnetite stick to the hub so the sensor would not pick up the signal. have you ever dropped a tool in sand and when you pick it up there is a fuzz on it thats magnetite. it sticks to any thing that is metal that has a bit of magnetic property. the hubs are grate magnets its very week but makes the stuff stick.


go to the auto part store and look at a 2004 hub assy. you will see that the sensor pick up is inside the hub bearing. no way exterior debris can get to it. a sealed unit. the other sensor is inside the transmission.

with gravel stuck in the tire tread this can cause slippage.

Sorry I havent been cruising the boards here lately, but from the looks of it, you are on the right path.
Here is a copy of a GM bulletin that applies to you concerns of low speed ABS activation.
Someone else mentioned the problem of the ABS pump running all the time...that is a separate issue caused by an internal failure of the ABS module....there are NO RECALLS on these issues at this time.
On the subject of the ABS pump run on, there is a gentleman on these boards..I believe his name is Ken Spragg of circuit solutions that had a fix for this...If someone can get in touch with him and have him contact me, it would be greatly appriciated.



here is the bulletin

Antilock Brake (ABS) Activation At Low Speeds (Clean Wheel Speed Sensor Mounting Surface) #03-05-25-007 - (09/29/2003)
Antilock Brake (ABS) Activation At Low Speeds (Clean Wheel Speed Sensor Mounting Surface)
2002-2004 Cadillac Escalade, Escalade EXT

2003-2004 Cadillac Escalade ESV

1999-2004 Chevrolet Silverado

2001-2004 Chevrolet Suburban, Tahoe

2002-2004 Chevrolet Avalanche

2003-2004 Chevrolet Express

1999-2004 GMC Sierra

2001-2004 GMC Yukon, Yukon XL

2003-2004 GMC Savana

2003-2004 HUMMER H2

Condition
Some customers may comment on ABS activation at low speeds, usually below 8 km/h (5 mph). Upon investigation, the technician will find no DTCs set.

Cause
The cause of this condition may be an increased air gap between the wheel speed sensor and the hub reluctor ring due to rust and debris built up on the sensor mounting surface.

Correction
Measure AC voltage and clean the wheel speed sensor mounting surfaces.

Raise and support the vehicle. Refer to Lifting and Jacking the Vehicle in the General Information sub-section of the Service Manual (SI Document ID #899664).
Disconnect both the front wheel speed sensor (WSS) connectors at the frame and harness.
Place a Digital Volt Meter (DVM) across the terminals of each WSS connector.
Rotate the wheel clockwise approximately one revolution per second. The minimum reading should be at least 350 ACmV's. If the reading is less than 350 ACmV's, remove the wheel speed sensor. Refer to the applicable Wheel Speed Sensor Replacement procedure in the ABS sub-section of the Service Manual. Plug the WSS bore in order to prevent debris from falling into the hub during service.
Clean the WSS mounting surface on the hub to remove any rust or corrosion using a wire brush, or equivalent.

Important
Make sure that the sensor sits flat on the hub. Check the sensor flange against a straight edge to ensure flatness. If the sensor flange is distorted, replace the sensor.


Apply a thin layer of bearing grease to the hub surface and sensor O-ring prior to sensor installation. Use ONLY Wheel Bearing Lubricant, P/N 01051344 (Canadian P/N 993037).
Install either the original sensor or a new one in the hub. Ensure that the sensor is seated flush against the hub. Refer to the applicable Wheel Speed Sensor Replacement procedure in the ABS sub-section of the Service Manual.
Place the DVM across the sensor terminals and recheck the voltage while rotating the wheel. The voltage should now read at least 350 ACmV's.


what is the sight for this bulletin

what is the sight for this bulletin

this is the recall that applies to my 2000 silverado. your dealership must work with you to give you the info on you vehicles recall work completed concerning this.

If you have this problem post back first what vehicle you have mileage and whats exactly going on.

a rusted /defective hub bearing will also do this..you do not want the dealership replacing both hubs unless you got alot of cash.

this is the recall that applies to my 2000 silverado. your dealership must work with you to give you the info on you vehicles recall work completed concerning this.

If you have this problem post back first what vehicle you have mileage and whats exactly going on.

a rusted /defective hub bearing will also do this..you do not want the dealership replacing both hubs unless you got alot of cash.

thanks for the quick reply - peace