what does the SLOW DOWN Light mean?

A common problem: do a search here for details.

see ...

http://www.ferrarichat.com/forum/search.php?searchid=6554524

 

You are too fast!

Pete

 

FWIW, I sent my F-car to Dave at Scuderia Rampante for installation of his clever gold pin connector kit, hoping to "nuke" this problem once and for all. Will report upon car's return.

see ...

http://www.ferrarichat.com/forum/showthread.php?t=312756&highlight=gold+connectors

 

It usually means your catalyst is overheating and the engine power is being reduced to prevent it from being damaged.
You need to find the cause of the overheating and most likely you will also solve the lack of power problem.
At this point I will recommend you check the plugs to make sure they are all firing correctly, as unburnt fuel in the cylinders would ignite in the exhaust and consequently overheat the catalyst.

 

Fixed. :O)

It usually means the ECU's for your thermocouple's are broken and sending the incorrect signal to the Motronic. The ECU's are utter garbage and the thermocouples are not much better.

 

Try swapping the Ecus from right to left and see if the SD light changes side on your display.

It's a pretty simple procedure to do in less than 10 minutes.

If the light switches sides, the Ecu is faulty and must be replaced. If the light remains on the same side, your cat is overheating...

 

Had this problem on my 550. Replaced the ECUs, problem solved. Took ten minutes and a socket wrench.

 

Can anyone direct me towards the ECU part number please?

 

179278: 179278 CATALYST TEMP. ECU - Ricambi America, Inc.

We have them in stock for shipment today.

 

I'd just come back to answer my own question. Thanks for your quick response.