Q45a generations and differences

[ceningolmo]

Ok... so, now that my Active is well on its way to restoration, I have a question.

It had been speculated by someone a while back that there may have been software updates as the Active was refined between 1990 and 1995.

Can anyone confirm this? Years that were updated? What did updates add, remove, change? Is there enough benefit in the updates to warrant changing my 1991 Active control unit to a later edition?

Thanks for the help...

P.S. - Yes, Brian, I did use the search button.
Modified by ceningolmo at 12:14 AM 7/21/2006

[Q45tech]

Just like ecu and tcu there were fine software tweeks every year and a major software change in 1994................I expect that you could swap Active computers without problems assumming the hardware was recharged [9 accumulators].

[ceningolmo]

The 4 accums attached to actuators were recharged and installed 2 days ago. The other 5 were all recharged a few years ago... they are still working, but probably could stand another recharge soon. I will probably deal with that in the spring.

The system self diagnosis showed a few things that I have already corrected. System diagnosis now shows "system normal", and everything feels like it is running well.

I need to do a full system fluid flush. I will probably complete that in the next 4-6 weeks. Also need to finish running a little Lubeguard Red (per Keith's instructions) through the system.

Seems like the system is in good enough shape to take advantage of a later computer. Tech, do you know what changes were made in the 94 software and why it was changed?

[texasoil]

I am not aware of any Active computer updates. There were several changes to the rear control valve and multi-valve to resolve non-operational issues--on some cars at some temperatures, the body would 'jerk' after the engine was shut off--sometimes 10 sec, sometimes 30 sec, sometimes a little, sometimes an inch or so. Had to do with the balance of pressures front to rear when the 'fail safe' valve opened and equalized everything. Did not change the 'active control' system at all. There are 2 versions of the rear control valve and 2 versions of the multi-valve. Interchangeable.