Instrument power failure

[mogman]

Problems with 2002 130 TDi Passat. When driving lose power to the dash board. Started when the car was new with the speedo, revcounter, fuel gauge and temp gauge going to zero and then swinging back into operation. Trip and clock would zero at the same time. Has now got worse to the point that all power is lost to the dashboard including illumination. All dials “freeze” in position and all digital displays go blank. Although the engine continues to run it appears that the car thinks that the ignition is turned off – the electric windows fail to work, if the lights are on you get the audible warning, if you open the drivers door the interior light come on and then switches off after the normal delay. Under these conditions if the car is stopped it will not restart unless the battery earth is disconnected and then reconnected. Even this "trick" is getting less successful. Sometimes the car needs to be left several hours before it can be restarted using this process. Had to call out the RAC last week whilst on holiday in France. The French VW agent was not really sure of the problem after running the diagnostics but needed to order a 3B0 920 927 AX from Germany – they said it was some type of computer in the dash. This did not arrive in time so returned without the repair. Failed again today driving into work
The “Haynes” manual refers to a “convenience unit” ECU under the front passenger seat which seems to have some control over the windows, dash illumination etc
- Any ideas?

[kenney]

3B0 920 927 AX is i beleive a dash panel insert exchange unit,which i would agree with our French VW agent.is the cause of your problem.I do not think the fault is related to the CCU