i did a bit of reaserarch and came up with these codes if there any help
C1210 ABS Outlet Valve Coil RF Circuit Failure
C0121 Valve Relay Circuit Malfunction
these are the only two codes i could find with c121 in them,
if im right im pretty sure the C at the start means it is chassis related.
someone should be able to correct me if im wrong,
all codes are OBD 2, so they are all relitavely the same, just some cars will have extra stuff for likes of 4 wheel drive etc.
heres the link to the site that i found them at....
http://www.obd-codes.com/trouble_codes/obd-ii-c-chassis-codes.phphope this helps