1996 Chevy ABS update:
 

Well had the codes scaned for my ABS light always on. I got the
following: C0021, c0022, c0026,c0035, c0037.

He asked me if I had unpluged anythign and I told him I had at the
module under the hood earlier in the week. He did some fidling with
his scanner and said the codes came back again and that the unit
either was bad, or there was a ground problem somewhere.

This is my daily driver but has 315,000 on it so I dont want to put
alot of money in it. I do all of the work on it myself. Thing is, I
think it needs a master cylinder. But, if the ABS cant be cylced to
purge air, how can you do it? Elsewhere in this forum someone
suggested a procedure which I am willing to try, but if I mess up and
get somethign wrong and get air in the system I am not sure what I
will be able to do.

1) Is it possible or even feasible to just , with new plumbing,
bypass the ABS module. (Run lines directly from mast cylinder to
brakes.

2) If this could possible be a ground, where do I look?


I will say maybe once every two months I get in it and the light stays
off untill I get on the highway. My hopes go up thinking it fixed
itself then it always comes back. 90% of th etime the light comes on
as soon as the key is turned over.

I appreciate any help as I am at a loss.

1996 Chevy ABS update:
 

On Fri, 28 May 2010 11:05:22 -0700 (PDT), stryped
wrote:

Well had the codes scaned for my ABS light always on. I got the
following: C0021, c0022, c0026,c0035, c0037.

He asked me if I had unpluged anythign and I told him I had at the
module under the hood earlier in the week. He did some fidling with
his scanner and said the codes came back again and that the unit
either was bad, or there was a ground problem somewhere.

This is my daily driver but has 315,000 on it so I dont want to put
alot of money in it. I do all of the work on it myself. Thing is, I
think it needs a master cylinder. But, if the ABS cant be cylced to
purge air, how can you do it? Elsewhere in this forum someone
suggested a procedure which I am willing to try, but if I mess up and
get somethign wrong and get air in the system I am not sure what I
will be able to do.

1) Is it possible or even feasible to just , with new plumbing,
bypass the ABS module. (Run lines directly from mast cylinder to
brakes.

2) If this could possible be a ground, where do I look?


I will say maybe once every two months I get in it and the light stays
off untill I get on the highway. My hopes go up thinking it fixed
itself then it always comes back. 90% of th etime the light comes on
as soon as the key is turned over.

I appreciate any help as I am at a loss.

I don't know about your specific ABS unit but I have seen problems
with various electrical devices where they were grounded to the
vehicle body and the negative battery cable is connected to the engine
block and the connection between the engine and the body has
deteriorated, so I would check where the ABS unit is grounded and then
confirm, with a meter, that the path from the ground point to the
battery negative terminal is essentially at "0" ohms resistance.

This may not fix it but at least it would let you eliminate one thing
from the discrepancy list.

Bypassing the ABS is perhaps not the best thing to do as all cars have
a greater braking capacity at the front then the rear as most of the
braking is done with the front wheels. This brake balancing is done
several ways. By larger or more powerful brakes on the front then the
rear, or by a pressure reducing valve for the rear brakes. The ABS
system may incorporate this function and you really do not want to
eliminate this balance as it will cause the rear brakes to lock under
normal braking conditions.

John B. Slocomb
(johnbslocombatgmaildotcom)