ESP/VDC Problem

[Kamen666]

Hi to everybody,this is my first post here,and i'm beging for help
Before one year i bought a Alfa Romeo 156 12.2002 1.9 JTD
I love this car !
But from one month i have a serious problem
The ecu give me a constant mistake in VDC in my car
I go about 5-6 six service,they put my car on tester and nothing....
The mistake is:
C 1520 - Can terminal -> bad connection
C 1521 - Can Terminal -> bad connection

and nobody can delete this mistake from ECU,and nobody can help me here in Bulgaria...
Can you please tell me where i can find these terminals to clean them (whit a contact spray for example),or can somebody show me a grafic or something helpful.
this forum is my last hope.....
Sory for my bad english
Greetings from club alfa romeo bulgaria
Sincerely
K.Todorov

[Kamen666]

I didn't get... does the system work or not?
Or u wanna just delete the errors?

The system doesnt work....
ASR is off at all the time
i want to clean this "can terminals" and everything will be fine,but i dont know where to find these terminal clam/axle
maybe they are somewhere under the dashboard...

[Colin Byrne]

CAN needs 2 signal wires to work properly (CAN HI and CAN LO) so it is pretty unlikely that it is just a bad connection but if you want to check and clean the terminals you need to locate the hydraulic unit (the aluminium box that all brake lines are connected to) on top of this is the ECU which has the vehicle harness connected to it, you can undo this plug and remove, and clean it if required. MAKE SURE THE CAR IS SWITCHED OFF WHEN YOU DO THIS.  I think there is a BOSCH unit in that car and the connectors that are used are very high quality so it is very unlikely that this is the problem.  It sounds like there is a failure on the CAN Bus this could be caused by some other module being unplugged somewhere else as can bus's require terminating resistors that are usually placed in modules so if one module is unplugged. i.e engine control module it can upset other modules.  How sure are you that those error codes are correct? other failures that will stop esp from functioning can be
-failed steering angle sensor
-failed yaw rate sensor or lateral acceleration sensor (usually contained in same sensor)
-a failed wheel speed sensor will put the vehicle into backup EBD so you will see the ABS light on the dash as well

[Kamen666]

10x for your answer
today i find and fix the problem and now i'm very happy
I understand in other forum that 65% of Alfa 156 & 147 has the same problem...
this "thing" has something to do with the steering wheel angle control sensor,
today i remove the top end of the steering wheel and check the wiring with it's terminals and voala ,one jack was corrupted,now everything is fine,and without message: VDC System Failure... bla bla
I think that this info will be halpful for somebody like me