BY JAMES BERRY (^) I PHOTOGRAPHY BY THE AUTHOR
Technically Speaking
Q:
I am having a problem with my
200 1 Corvette. The antilock
braking system (ABS) and the brake
lights are on. I have a code reader and
have tried to diagnose the problem.
I am having a reoccurring fault code
C1214 Solenoid Valve Relay Contact or
Coil Circuit Open.
I was looking on the Corvette blogs
and it seems like there may be a prob-
lem with the Electronic Brake Control
Module (EBCM). I purchased a used
EBCM from a salvage yard due to the
cost of a new one. Now I have the same
fault code and an additional fault code
C1242 Brake Pressure Modulator Valve
(BPMV) Pump Motor Ground Circuit
Open. I am trying to repair this myself
due to the cost and any help would be
appreciated. Also, what the heck is the
EBCM used for? Is it possible to bypass
this system?
Thanks,
Rick
A:
Rick, basically this is how the sys-
tem works: The Enhanced Traction
System (ETS) is designed to limit wheelslip
during acceleration. This is accomplished
by cutting fuel to selected cylinders, retard-
ing spark and upshifting the transmission.
The EBCM monitors wheel speed slip
through the ABS wheel speed sensors and
determines the desired torque reduction
needed to minimize wheelspin. So bypass-
ing this system is not recommended.
There is a common problem with EBCMs
made by Delphi. It appears that they have
issues with cold-solder joints. It is possible
the used unit you purchased had the same
problem as your original unit.
This is something you can repair your-
self if you are adept at using a soldering
iron. There are also companies repairing
these units so you can either purchase
a repaired unit or send in your unit
for repair. One of these companies is
http://www.absfixer.com.
There are a few items you should check
before sending your unit off for repair:
Make sure the battery is not failing inter-
nally and the alternator is charging cor-
rectly. These fault codes, as well as many
others, can set if the battery voltage is low.
Perform a visual inspection of the wires
at the EBCM for a good connection or for
any obvious signs of damage. These wires
are near the serpentine belt and I have
seen the belt rub and cut these wires.
Check the pins at the EBCM connector
to ensure that they have not been bent
or damaged; also check for any signs of
corrosion.
If you are going to try and repair or
replace the EBCM, note that it is a dry
module, meaning that you can change it
out without having to worry about bleed-
ing the ABS system. The EBCM has a large
wiring harness coming out of it and has a
white sticker on top with the part number
and other information.
The EBCM is attached to the Brake Pres-
sure Modulator Valve (BPMV), this is the
unit with the brake lines coming out of it,
and all of the brake fluid is contained within
Fixing 2001-
Corvette ABS Fault Light
Check all of the fuses using a test light.
We have covered this several times in
previous articles. Pay special attention to
fuse #52 in the underhood fuse block, a
maxi 40-amp fuse. Also check the fuses
in the box under the passenger side of
the dash.
jacob rumans
(Jacob Rumans)
#1