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C5 Issues with the ETBCM


Well-known user
There is a common C5 issue across the board of all model years of C5 related to ABS, traction control, etc

Many many owners have had this problem and either got it shoved by a dealer charging $2,000 (US) to replace the ETBCM controller
or maybe half that for a used one

In almost all cases the problem is a $2 relay
To save weight and money GM uses all over the controllers a simple very small relay
Over time, heat and bad roads this relay either is dead or stuck in one position

If you or a friend can swing a soldering iron, the relays can be bought via cyberspace for about $2 ( I buy several so have spares and no one uses these anymore )

  1. Best is pull off the top radiator hose to get free room for the ETBCM controller is below that
  2. remove about 6 screws from mount and pop controller off
  3. Put that on a table and take the screws off that hold the 2 case halves together.
  4. It will be a bit of bitch to then crack the 2 apart as there is sealant between the 2
  5. Once open notice below in my image, the white colored small square relay
  6. clean any crap around it and un-solder the 4 legs and take out.
  7. take new relay and clips those 4 leads down so not as long and install it same direction as old one
  8. Solder those 4 legs and BTW check if anything else needs to be re-flowed with solder.
Reverse install and if need be clear any error codes ETBCM had from bad relay



CCCUK Member
Was this the process that was shown on a recent Wheeler Dealer's show? In that case they went to Corvette Mike's place for a chap there to do it. From what I've read, it could be a godsend to C5 and 6 owners!


Well-known user
I do not know of the places you mention but anytime a controller has to be taken out and round trip shipped there is
the added down time for the car until the controller returns
At least if C5 owner can do a simple replacement of the relay the car can be back on the road within couple of hours.

Also that same relay type is used on other controllers of C5 so having some spare relays on hand will be useful to
other repairs needed and being relay is no longer being used vendors who made them no longer are so while supplies
last best to own some spares if keeping their C5s long term


Regular user
There is two different of EBTCM´s for C5 .
One for the 1997 - 2000 (with V-code ) or without Active handling(M-code) and another type for 2001-2004 models .
The 97-00 and the 2001-2004 are not interchangeable without modifications :)
Post one above is for the 2001-2004 version of the EBCTM
The older version shown here contain two relays , one for the ABS pump and one for the solonoid .
If you have some soldering skills these relays are possible to replace.
I bought a cheap Cadillac EBCTM (99 Seville) which is very similar to my 2000 Corvette without Active Handling (Code M)
and managed to replace the relays .

1997-2000 EBCTM_BMPV code M.jpg1997-2000 EBCTM_BMPV code V.jpg

2001 -2004 . This EBCTM contain one relay supplying the ABS pump and solonoid with power
I replaced this relay on my friends 2002 EBCTM after he get the code C1214 three months ago .
This is a much easier job then replacing relays on the 97-00 EBCTM´s.
Sometimes the soldering on the relay card need to be resoldered on several points without replacing the relay .

10_ABSmodul m partnr.jpg21b_Nytt rele montert på plass.jpg