ABS Light on


Ruger9mm
05-28-2003, 12:09 AM
I have a 99' silverado and last night the ABS light came on and will not go out. Does anyone have any ideas what I need to look for. Also the emergancy brake is way out of adjustment. I can put the emergancy brake on and it goes to the floor, however it doesn't really hold. I'm really concerned about the ABS light.


it is a 1500 5.3liter


Thanks

Ruger

Flatrater
05-28-2003, 08:52 PM
Only way to find out your problem is to hook up a scanner and read the codes! Its a hit or miss with the proper info to fix it!

Ruger9mm
05-28-2003, 09:40 PM
Thanks Flatrater, I'm going to have a freind hook it up to a code machine that he has at the shop he works for... Hopefully it will not be to bad.

Ruger9mm
05-29-2003, 09:12 PM
Well I had my truck put on a machine and it gave me a code of

U1041 Loss of EBCM Communication

Can anyone tell me what this means and how can I find out if there is a recall for brakes or anything else for a 1999 Silverado

bowtiebandit
05-29-2003, 09:42 PM
First make sure all the ABS fuses are good, second check for power and ground at the ABS module just below the drivers door mounted to the frame.
Do you have a strange motor type noise all the time? These modules are know to continue to run and set the light off.

Ruger9mm
06-02-2003, 10:55 PM
Well I ended up taking the truck to the shop and it took them 2 days to pin point the problem and they say it is the EBCM (electronic brake control) module went out. They want to charge me $900. Does anyone know where I can get a used one or somewhere else cheaper. It is for a '99 silverado 1500 2 wheel drive


Thanks

thrilla92
06-16-2003, 07:52 PM
the reason why this might be happing is because the abs sensor to one of the backing plate on back of brakes is rubbing against your tire or wheel

Gavin Curtis
07-03-2003, 03:46 PM
If you had to pull the fuse because of the pump motor running all of the time, you can have it permanently fixed for about $100 instead of buying a new one. The replacement ABS controllers still have the same problem, but the repaired ones have an upgraded part and should not go bad again.

The pump motor control switch (electronic) originally equipped in the ABS module has a 75 amp contact rating and the "contacts" weld together from the pump motor starting current. The new switch that is intalled has a 104 amp "contact" with a 360 amp surge capacity.

They asked not to advertise peoples services here, so email me for more information on who to contact.

This repair can save a person a lot of money.

Gavin Curtis
07-03-2003, 04:04 PM
Ruger,

The ABS controller is a full blown computer that communicates to the engine control computer and several others in your truck. They communicate on a two wire serial data system.

Either the communication electrical connections between the engine control computer and ABS controller are bad, the ABS has no power at all or remotely possible the voltage regulator in the abs module has failed (if the ABS fuse is intact and in place and the module is getting power).

Try disconnecting the battery then unplug/plug the communications/logic power connector from the ABS control unit. The communications connector is the larger rectangular plug with many small wires and not the two smaller oval shaped ones with the large wires.

After reseating the communications plug, connect the battery to see if serial communications have been re-established.

Has the ABS fuse pulled because of the constantly running pump motor? If so, the unit can be repaired (no need to replace).

EdCrabb
01-01-2004, 09:40 PM
I have a similar problem. I just bought a 1999 Silverado LS 1500 5.3L. The Brake and ABS lite stay on all the time. Checked the fuses, and they were good. Took it to the local Chevy dealer, and asked the Service writer ( a firend of mine) what he thought it was. He replied the ABS pump was shot. I dont have a running pump sound at all.

If I can replace the pump for $100.00 with a rebuilt unit I would love to know where to get it.

Thanks,


Ed Crabb
Molalla Oregon
sbjake@molalla.net

Bubba14
01-02-2004, 09:24 AM
I had a similar problem with my ABS, it is now fixed and working well.
I sent mine to Circuit Solutions. I sent it to them on Tuesday
and recieved it back on Friday. (I used Fed Ex overnite) They saved me a bundle of money and the ABS works fine. I highly recommend them to anyone. Check them out at out www.circuitsolutions.info
Bubba14



I have a similar problem. I just bought a 1999 Silverado LS 1500 5.3L. The Brake and ABS lite stay on all the time. Checked the fuses, and they were good. Took it to the local Chevy dealer, and asked the Service writer ( a firend of mine) what he thought it was. He replied the ABS pump was shot. I dont have a running pump sound at all.

If I can replace the pump for $100.00 with a rebuilt unit I would love to know where to get it.

Thanks,


Ed Crabb
Molalla Oregon
sbjake@molalla.net

EdCrabb
01-02-2004, 10:03 PM
I had a similar problem with my ABS, it is now fixed and working well.
I sent mine to Circuit Solutions. I sent it to them on Tuesday
and recieved it back on Friday. (I used Fed Ex overnite) They saved me a bundle of money and the ABS works fine. I highly recommend them to anyone. Check them out at out www.circuitsolutions.info (http://www.circuitsolutions.info)
Bubba14

I looked up the information and it looks like I can repair the module my self. Its a matter of replacing a not so heavy duty relay/switch in the module with a real heavy duty (higher amperage) unit. Since I am an electronics engineer, I should be able to take care of it,

Thanks Buba!

Ed Crabb
Molalla Oregon
sbjake@molalla.net :grinno:

Gavin Curtis
01-30-2004, 05:23 AM
EBCM communication failure is most likely due to a bad serial data transceiver IC. The EBCM can be repaired for $100.

Yazowski
10-11-2012, 11:47 AM
2003 Silverado 1500 LD 4x4.
Same issues with ABS. On-going for over 2 years.
Some have suggested just pulling the ABS fuse and tollerating the ABS light staying on. May do that out of frustration.
Dealer suggests "possible" fix is replacing the hub assembly. That was done in a prior attempt in 6/2010, "fix" lasted about a month to three months as I recall. Has been a constant issue before that and since that.
I'm interested in the idea of "fixing" the module by changing out the relay to a more stronger rated one.
Where do I: send the module? or buy the stronger relay? or have the fix accomplished (what do I tell my mechanic that I want done (so that I avoid many costly attempts to fix that do not fix)?

j cAT
10-11-2012, 12:59 PM
If you live in the rust belt the front hubs are #1 cause of this ABS light being on.

If the output of the front hub sensor is not there ,the ABS lt will stay on.

other things may also cause this to occur so an OEM ABS brake code scanner will get you to the correct solution.

the front hubs need be replaced with timken bearing hubs. If aftermarket chinese hubs were installed it is normal for failure after a few months.
been there done that.

other tests and inspections can reveal the hub condition. rotating the hubs and measuring the output voltage .375 volts AC or more.

removal of the sensor and checking the grease for rust. if the grease is rusted then the grease seals have rusted out causing sensor/hub failure.

since the light is on you need not remove the fuse because you have no ABS. with the sensor output being intermittent then you would need to remove the fuse because of ABS activating causing you to not being able to stop.

could be the relay also inside the abs conrol module.
codes will tell..

Yazowski
10-11-2012, 01:46 PM
Thanks, j cAT.
Had the vehicle into the GMC dealer yesterday and into Monroe a few days earlier. Monroe said "no codes" stored. GMC reported on the codes that WERE stored. GMC says everything is within tollerances but that hub may be bad nonetheless and replacement is $680+ for the one side (left). That one was confirmed replaced by my private mechanic about 15k miles ago in June 2010 (no, I do not drive the truck much). Rust IS the issue here in Central New York, especially, it seems, on the 2003=- model year vehicles - not just Chevy. The amount of rust underneath this '03 suggests to me the "why" GM went bankrupt and Obama's office bailed out them and other manufacturers.
.
I hope to take this thread printout and another thread's printout to my other (now) mechanic for telling them: these are the things I want you to try to fix the ABS issue on THIS truck -- I'm paying you to do THIS.

j cAT
10-11-2012, 04:43 PM
Thanks, j cAT.
Had the vehicle into the GMC dealer yesterday and into Monroe a few days earlier. Monroe said "no codes" stored. GMC reported on the codes that WERE stored. GMC says everything is within tollerances but that hub may be bad nonetheless and replacement is $680+ for the one side (left). That one was confirmed replaced by my private mechanic about 15k miles ago in June 2010 (no, I do not drive the truck much). Rust IS the issue here in Central New York, especially, it seems, on the 2003=- model year vehicles - not just Chevy. The amount of rust underneath this '03 suggests to me the "why" GM went bankrupt and Obama's office bailed out them and other manufacturers.
.
I hope to take this thread printout and another thread's printout to my other (now) mechanic for telling them: these are the things I want you to try to fix the ABS issue on THIS truck -- I'm paying you to do THIS.

The rust belt here where we live is quite a PITA.
I just pick up my 2000 SIL 1500 4X4 from the frame repair shop. the rear crossmember was rotted to nothing where the tank passes over it.

GM used that wax coating over the frame / components. as this lifts off the metal it traps the corrosives , my inspection last month I only saw a small 6 inch long crack. when I was done , that wax coating removed the crossmember was 2/3 gone. very lucky for me I found this before the fuel tank fell off.

The frame shop was surprised that the vehicle is in excellant condition except for that metal tube !

I have done these hubs and some testing reveals whats up. the dealer should have found ABS codes. If the light is on you must have a failure. with those codes I can tell you whats wrong.

The hubs come with the sensor. this is because they are matched to provide proper output. the distance from the hub encoder gear to the magnetic speed sensor pick up determines the voltage. now since this is a magnet any rust in the hub/grease will cause the sensor to not produce a voltage.

the timken hubs at auto zone cost about 190.oo . I got some chinese hubs for 70.00 ea and they suddenly failed and I could not stop. the ABS just kept operating killing the brakes. lucky for me I had a 2 yr warr and got my cash back.

now that I have the timkens the vehicle is perfect .

It is quite surprising that these so called mechanic experts just don't understand these electronic systems.

working on transportation vehicles with these controls since the 1970's it is no big deal.

that frame work that was just done cost 400.oo. they did a very good job . excellant welding quality. better than GM !

Gavin Curtis
10-11-2012, 10:13 PM
Yakowski,

Check the ground connection of the abs module. It's a heavy wire terminal under a sheet metal screw near the ABS unit on the frame rail. Clean and make sure you have a good electrical connection. If you still have the ABS fault and you are in a rustbelt area, send BOTH the pump and module pack to modulemaster.com

If only orange ABS light, you have a hub/sensor problem. If BOTH ABS and red BRAKE, then module and possible pump are the problem.

Module will be 100% restored. We need to inspect the pump motor internals as corrosion will penetrate it as well. Motor will be sealed to protect it against that crappy salt and mag chloride. It destroys the motor endplate and brush pack.

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