hlgraff

Nothing has worked, sadly : the dealer can offer no solution except to replace the PCM unit and a 1,4,8 re-boot did nothing to cure the bug. Pity. I think I'll live with it. A replacement is too expensive in the circumstances. Thanks for your help everyone. Howard

Thank you both. I have never tried the 1,4,8 reset and will try that too, as well as asking the dealer to do the reset with the PIWIS unit.

Thanks.... If that's standard Porsche diagnostic equipment I rather think that the dealer must have tried that by now, but I'll nudge them. Thanks.

Thanks for your reply - what is a PIWIS unit?

My car's PCM unit is showing strange memory anomalies and the dealer simply says "you need a new unit" which I think is a cop-out. The unit works perfectly (including navigation) except: 1. It always thinks it's summer time (adds one hour). When I go into PCM Settings to untick summer time, the car's clock clicks back one hour and is fine for the rest of the journey, but after the ignition key has been removed and re-inserted and the car re-started, summertime is back. This happens all year round. 2. The always thinks the "last destination" for navigation is always shown as one particular destination that I once drove ages ago in High Wycombe. The navigation otherwise works fine (I can enter a new address and it works) but the "last destination" always shows as that place in High Wycombe no matter where I last asked the system to navigate to. 3. I cannot store any new destinations. They simply don't store although the PCM unit issues no error message when I tell it to store the destination. 4. If I delete all the stored destinations in the PCM unit, one at a time, until they are all gone, if I then turn off the engine, take the key out and then turn the car on again, all the deleted destinations magically reappear! The above errors are really annoying, especially the fact that I can't store any new destinations, including the true "last destination". I have a Dension Gateway 500 unit in the car, connected to the PCM unit, but the dealer disconnected it when testing the PCM unit and he still couldn't make the problems go away. The Dension unit is working fine - iPod connection in place of the Porsche remote CD player, and bluetooth phone. I am particularly puzzled as to where the unit is storing the deleted destinations so that it can restore them again on the next start-up! Any ideas anyone? Thanks in advance Howard London, England.