Mercedes C230 Kompressor

[ALEX36]

Hi all,
I have a real bad problem with a c230 Kompressor.
Background infomation is as follows.
Vehicle brought into workshop as non starter,
found fuel pump wire at rear sam unit burned,
wiring repaired and sam unit renewed and coded with star.
problem now is that the engine managment light is on and the esp warning is on dash. The vehicle in this condition will not respond to accelerator and runs very poorly. Trouble code for engine is throttle actuator, trouble code for esp is can comunication interupt. Both faults will not clear.
If you have read this far and are not totaly bored here comes the interesting part. If the vehicle is started and the ignition switch is very quickly switched off and back on without letting the engine cut out the trouble codes for both become stored not present and the vehicle drives fine until you switch off and resart, which takes you back to stage one.
Now I know this one is a cracker but any one got any ideas?
P.s. I have spent three days on the vehicle and am getting no where fast.

VEHICLE NOW REPAIRED, CONNECTIONS TO ENGINE MANAGMENT ECU CORRODED AND WATER INGRESS CAUSED THE PROBLEM.
THANKS ALEX