PeachParts Mercedes-Benz Forum - C200 Kompressor 203 CAN Problem

I have a problem with a C200 Kompressor 203.
Intermitantaly it brings up "ESP, Brake pad wear"and recently the speedo would swing to full scale.The problem has been going on for some time and the agents have replaced the ABS control module, Steering angle sensor, Electronic ignition switch.
I have connected 2 Fluke meters, 1 to can hi and 1 to can low, I intended to drive the car until the car faulted but after 500km's it did not play up, it was when I left the key in the on position while stopped, I noticed the can voltages had both dropped to 1.5 and 1.7 volts, the started would not connect in the start pos. We disconnected the speedo can plug, (this was where we had the meters connected) and the voltages increased slightly but not back up to the 2.4 and 2.6v. Turning the key off and on again and the voltages were back to normal. We cleared the faults.

Since then we have not managed to get it to play up again.
The faults stored was PO600 (CAN signal interupted).
Any help would be appreciated!