F355 Slow Down Dash Light Flashes

When the ignition is turned on on my friends 355 the Slow Down Light on the Dash Flashes on and off, can anyone tell me what this is indicating, it is on as soon as you start the car, on Tickover or driving normally

 

I have had this problem on my 348 twice--it PROBABLY means the oxygen sensor is bad. The system is set up to send the warning when the catalytic converter gets too hot (slow down so it cools) but since it comes on when the engine is started the computer is getting a bad signal. The oxygen sensor is VERY easy to replace, and I just bought one from car-engine-parts.com for under $200 including the special harness and connector.

 

Bill, Thanks for the info, I am pretty sure he had some sensors etc.. replaced last year, I will ask him what was done and post back on here

 

If it happens when the engine is cold, it could be a faulty Catalytic Converter Temperature ECU.

It is usually one of three things.

1) Bad Cat Temp ECU
2) Bad Thermocouple
3) The Cat is actually over heating.

In short try having your friend swap the cat ecu's from one side to the other to see if the light comes for the other side. Do a search of the archives as this has been discussed many times.

I don't think it is a problem with your buddy's O2 sensor, because if it was you would have also gotten a check engine light. I'm betting it is either a bad ecu or thermocouple.

 

Thanks for all your info, are these easy accessible

 

I had this problem -- on my way to the dealer the problem went away.

That was the longest i had driven the car since the problem happened.

One theory -- there is a crack on the ECU plastic that let water in. When i drove the car for a while, it got things nice and hot -- burning off any moisture that was left?

 

I just see your thread with the same problem, the car is kept garaged and never taken out in the wet, as soon as we get to the bottom of it we'll post it here

 

Yup.

This thread is for a 348 but the exhaust ecus are in the same location, and look the same. http://ferrarichat.com/forum/showthread.php?t=57066
and one more
http://ferrarichat.com/forum/showthread.php?t=89929

Like I said, do a search of the archive there is plenty of info on this.

 

Thanks again, those other threads are really useful