I've had need to de-garbage a micro in my GV recently to do with repairs to the ABS system, and members should note this:--

Just removing the negative lead from the battery for a minute or so in NOT ENOUGH. The only sure way to clear garbaged RAMs is to remove the negative lead from the battery and then hold that same lead in contact with the POSITIVE for a minute or so. When I did this, I heard the familiar slight "crack" from a discharging electrolytic capacitor. This procedure leaves the negative post of the battery un-connected to anything at all. There will be no big flashes. There are non-volatile RAMs, i.e. NVRAMs, but we don't know if these are fitted to GVs, but doubtless the NVRAMs will cost more.

I know from long experience that RAMs will hold memory down to a volt or so from a much higher nominal operating voltage, usually either 5volt or 12volt. Normally this is considered a good thing, but certainly is not in our case when we wish to clear out any aquired garbage from glitches or in my case redundant data. It would be true to say the better the quality of the RAM, the more likely it is to retain data in poor circumstances like low supply. Hence deliberately discharging that electrolytic capacitor by the above procedure. Such a capacitor can hold its charge for very many minutes, and the charge decays exponentially, meaning we can be talking about half-an-hour or more for a complete down to 0volt discharge. RAMs it should be noted consume a very small curent indeed, maybe pico-amps for a good one.

A further point is that my radio under the above procedure lost neither its code nor its station tuning data (2006 model year). The comprehensive heater did go back to default though, and the underfloor heater started up from cold, but went off inside a few minutes. There were no auto-shift changes (user-learned operation) in the autobox.
Leedsman.

 

I usually drive my GV to the local tip to remove my not-so micro-garbage.