Would appreciate info/advice on most common causes of this warning light. Mine is a 1999 F1 Berlinetta, 18500 miles, now in Miami, FL. After battery was changed out 2 days back, drove 2 miles, let it sit for half day, then drove again for a mile, light came on, engine sounded different, lost half of the power, drove half mile home. Now I am told I after the started car was started up, it should have idled for some 15 minutes for all lost settings to reset. True? Am also told by a certain knowledgeable person to turn battery to off position, then back to on after one minute, start up, then let idle for 15 minutes, then see what happens. If not, call your favorite dealer to request a tow. Many thanks.
I changed the battery myself in mine, I had no troubles and I didn't let it idle. I think your new problem is unrelated. I thought the slow down light had to do with exhaust gas temperature, especially the cats. Could you have a bad cat? or a bad sensor or ECU... Either way, I don't think you want to be driving it around with a SDL on. Sounds like it's time for the tow.
I've only owned mine for a few weeks, but when the manual came (ordered one because mine did not come with one) I skimmed through it, and I definitely saw something about letting it sit at idle for a while after having lost battery power. It did talk about letting the system re-establish lost settings. I remember reading this because the thought that crossed my mind was that they must have designed the battery on/off switch in such a was as to feed battery power to the necessary circuits to avoid this issue when using the switch (which I have used already - with no problems). Again, my comment is not based on personal experiences, but rather on material in the Owner's Manual.
I finally got a chance now to turn the battery to Off/On position. Started up the engine, watched the SDL blink for a while. Came back 15 minutes later and SDL had gone off. Am relieved for now but will know more when I take it out for a drive in the neighborhood. Am told that most of the times, it can be a cat problem due to faulty O2 sensors. All 4 sensors were replaced on this car about a year ago. Will report back soon. Thanks to all who responded so promptly. Enjoy the Christmas weekend, y'all.
If your cats are originals, that may be the case (bad). But the thermocouple ECU's are known for splits in the potting that can cause this too. Inspect them and silicone any cracks in the potting.
Good news! Fired it up again. Took it out for 20 minutes, no problem for now. Many thanks. Forgive me, but where exactly is ECU potting? During drives over last couple of months, I did notice SDL come on for a few seconds and then go off without any loss of power or performance. So maybe there's another minor problem elsewhere (good) and not with cats going bad (shudder).
Hey Dr. Dave, where did you order your manual from? I have a pdf version but would rather read a real double sided printed copy instead of printing it on 230+ pages of 8.5x11". Thanks -
Yes the ECU's have the potting. There are two of them behind the rear passenger wheel. Just forward of the vacuum reservoir (coffee can looking thing). They are mounted on a plate with two vacuum solenoids. I think the Owners manual may have a diagram, or check out the diagram on the "lateral protection" plate just forward of the right rear shock actuator. The other one is mounted to a structure bar just behind the drivers side rear shock. They are about 1x1x3 inches in size and have the logo "vescovini" on them. Hope this helps!
Thanks for pointing out the location of the ECUs. Will look for them tomorrow. The SDL is back again, not solid red (when engine will sound funny and will lose power) like last time, it is *blinking* this time. No funny engine sound, no loss of power. What think? Got to be (I hope) something simple. Maybe a ground fault. Had the same problem in my 328 and my indie mechanic in Houston disconnected ground and everything worked fine from then on for about a year till the car was sold.
Dear ferrariwalla355, I have exactly the same symptoms with my 1997 F355 - it is a euro version (France) and has covered 26.000 kms. The slow down light flashes all the time, even starting from cold - it is as if the flashing signal is frozen in the system. Otherwise the car runs normally and the cat converters do not seem to be running hotter than normal. Of course, as you, I do not like driving with the light flashing at me. To quote Ernie "in a nut shell, the slow down light is the CAT temp ecu's". Does this mean that we can discount the oxygen sensors? Unlike the 348, the 355 does not have separate warning lights for the two cylinder banks and swapping the temperature ECU's does not get me any further down the line. Unfortunately for me and unlike the US cars, mine has no connector block under the dash where I could connect an OBD II unit. I do not even know how I can cancel the flashing light to see if it was a one-off glitch (disconnecting the battery had no effect). Is there any fault tracing I can do with susequent miracle cure with inexpensive parts (!) or is it the expensive route to the Ferrari Service Centre and their SD1 diagnostics? Here's hoping................ Ronrob
My stop engine light would come on flashing with a cold engine and go out some times. Turns out the ground strap on my rear clutch cover was no grounding to the chassis - Note my Avitar - I removed it and sanded contact surfaces at both ends. Reinstalled it and light has stayed out for months.
Dear Aeroengineman, Many thanks for this - I had seen something before about grounding but could not fathom it out. It's 8pm in France, but first thing tomorrow the car will be over the pit and I will be at it with the sandpaper. I will cetainly let you know how I get on. If this works, you just might hear the yell across the Atlantic! Ronrob
Dear Dave the Aeroengineman, My yell should have woken you at 3am your time! Cleaned T/C to ECU connector and the earth strap as you suggested. After a reboot of the system (battery connect and 10 minute warm up) OUT WENT THE LIGHT! Fabulous and I cannot thank you enough - you and all the other wise owls whose threads I read. This allows rookies like me to learn and appreciate their Ferrari's - without taking the easy and expensive option. A million thanks, Sincerely, Ron Brown
I have the same problem with my 1995 GTB 2 weeks back. As my cat has been replaced with straight pipes (by earlier owner), my mechanic suggested that I bypass the cat control unit since its irrelevant to check on overheating cat.
Does anyone have any advice on how to do this on a 355? (Where is the control unit located?) I've had straight pipes installed as well and I'm also having the same problem. Thanks again guys! (My first post!) --Joshua
Behind the shock towers. Here is a picture of Jeff's famous pool cue pointing it out on a 348, but it's in the same place on a 355. All you have to do is unplug it. Won't take more than a few seconds. Image Unavailable, Please Login
Wow. That's night and day difference in terms of reliability. I'm still getting an occasional flicker out of the slow down light. Is that normal?
Hi guys hope you could help. I have been getting a SDL light on for sometime now and it goes on with my first morning ride and of and on throughout the day. I have noticed recently that my idling is jumping a bit up and down, can this possibly be fixed by disconnecting my battery connection and reconecting with a warm up? I sure hope so, oh and since my battery is in front of my front wheel do I just disconect one of those cables under the (red possitive + box) and which one? Any advice would be greatly appreciated!
