Hello fellow f-chatters. This is my first request for assistance and leveraging all your insight. Situation: 98 550 3,050 miles. I started the car after 2 weeks and the slow down message appeared. I turned off the engine, then restarted, the message appeared again. I proceeded to drive the car to get to normal operating temperature thinking the problem message may cycle out. Again I turned the engine off, then on again, same message. Remedy: After reading several threads, I proceeded to swap the ecu from left to right and right to left. I started the car and now there is no message. Clearly I am encouraged with the results, however I'm not sure what I actually proved? I am suspicious that I am potentially treating the symptom and not addressing the root cause. I did take the car for another ride and the message didn't appear. Next steps. I will invest in a heat sensor thermometer to record and track the cat temps(I have a lift, so somewhat easy. If anyone can give me an approximate range of normal temperature (average driving, not racing temps) that would be helpful. I'd like to solicited your feedback as to my approach, actions, and if there's something I'm overlooking. Thank you all so much..
Maybe a connector issue as evidenced by the ECU swap. Especially more likely because of the low miles, indicating there may be possible corrosion build up at the connector(s).
Congratulations on your purchase and welcome to the chat Rob. I am sure you will eventually get a post from Terry (Taz) who is the most knowledgable person you can ever imagine on the 550/575 (and a very nice guy too). What colour is your 550? Can you post some photos of it? Also, as they keep a record here of 550/575, perhaps you can post your VIN# as well. Cheers Clyde
Rob, the IR gun isn't a bad idea, but just be aware you'll get wildly different readings on it due to the surface emissivity and reflectivity that you're "shooting". Shiny, reflective surfaces are the worst for repeatability, while dark rough surfaces are the best. This cat converter overtemperature protection system is one of the more unreliable systems on our cars, and the electronic module that you swapped from side to side is responsible for most of the unreliablity. As others have said, get some contact cleaner, or WD-40, and clean up those contacts really well, both on the incoming thermocouple cable and the outgoing ECU cable. If that doesn't help, and the problem keeps reoccurring, those modules aren't that expensive to replace for the peace of mind it brings. Ricambi has them for ~ $370: Ferrari Parts : 179278 CATALYST TEMP. ECU : Ricambi America and Superformance in the UK sell them for around 150 GBP. In the 550 WSM, it indicates the lower temperature alarm (that triggers the flashing "Slow Down" light) happens at about 1720F (plus or minus 86 degrees), while the upper temperature alarm that causes the Slowdown light to go solid, and will shutdown the entire engine bank happens at 1778F (plus or minus 86 degrees).
Cribbj Thanks for the info on the relatively cheap ECU from Superperformance. I think I will have to order one for when the inevitable happens...
Thanks for the replies everyone. I'll take the advice of cleaning the connectors, they look exceptionally clean and no signs of corrosion or degradation, at least cosmetically. The temps are very handy and will take under consideration how to measure correctly (maybe 4 data points then take the average) Additionally, as mentioned, and pardon my lack of understanding on the ecu's. Although the light is error message is gone, is there any inherent risk that I'm over looking by swapping. Basically just because I don't see the error any longer, is there an underlying issue I should be considering to investigate anyway( sorry for seeming paranoid, just want to avoid a Ferrari BBQ) Clyde, thanks for pointing out Taz, you don't know how much I enjoy reading his posts and replies. Very grateful for his massive contributions Lastly, thank you for the welcome messages. The car is a 98 550 Grigio Titanio . Attached via Pinterest link are pics of the car.. Hope you can open the link,(let me know)if not I'll upload physical files . https://www.pinterest.com/rdellasalle/ferrari-550-maranello/ Vin for the car is ZFFZR49A5W0112495 Again, thanks for everything looking forward to additional feedback, however more importantly, have a great day and happy motoring!
Rob, those ECU's are pretty dumb, in fact they're just signal conditioners that boost the millivolt thermocouple signal up to 0.5 to 4.5v levels for the main Motronic ECU's to take action on. They have no memory, aren't paired, and can be swapped back & forth for troubleshooting, without any issues. And if a connector isn't making good contact, or the ECU isn't getting a good signal from the thermocouple, the Motronic will let you know about that too, as the Motronic needs to see a "minimum" signal coming out of them as a health check.
Interesting circumstance Rob.....mine is a bit different, and any insight anyone has will be appreciated. My '97 (high mileage and with no cats) runs like a top, but the "slow down" light starts blinking as soon as the engine is started, and continues to blink until the engine temps are up to their normal indications. The oil temp, press, and water temp never climb, and the slow down indication never comes back. My sense is that without the cats the ECUs are getting an initial bogus signal. Possible? As I said, the car runs flawlessly, and sounds amazing.
Bill, as mentioned below, the main Motronic ECU's will also flag up a Slowdown alarm if they're not getting a good signal from the 2 cat ECU's, and at cold startup, perhaps one of the cat ECU's has a dodgy internal connection or a thermocouple isn't happy, etc. Start by cleaning the connections. If cleaning doesn't help, figure out which bank you're getting the alarm from, then swap your cat ECU's from side to side and see if the problem moves with the ECU. If it does, then you've isolated the problem to the ECU and you can replace it. If the problem doesn't move, then it's probably a thermocouple or its wiring that needs changing.
Wil, you know, that's a good question - in the past I isolated it by using an OBD2 scanner and software, but I also thought the MFD (Multifunction Display) probably indicated which bank was overheating , but I just looked at the WSM and realised that it only gives a "Slow Down" indication, not which bank is the culprit. So......unless you have a scanner and software, or a known "good" cat ECU to substitute, it could be tough to isolate which bank is causing the problem.
John, don't want to go too far astray on the thread, and know there are a bunch of previous threads on this, but--what OBDII reader and software do specifically you like and use for a 550?
Wil I use the OBDLink WiFi scantool from these guys: https://www.scantool.net/scan-tools/pc-based/obdlink-mxwf.html and the ScanXL Pro software: https://www.scantool.net/software/scanxl-pro.html I'm sure there are better tools than these but they suit me. They're not as powerful as a Leo or an SD-2, but I haven't found anything that I needed to do that they couldn't handle.
John, great stuff--thanks much. I'd of course like to have a Leonardo or SD2 as well, but the price for your tools are affordable.
You have my old car This was another thing on my "to fix list". This car shares a lot of systems similar to the F355s, and I'm certain the way to fix this is to replace the thermocouples (exhaust temp probes). My 355s did this and after replacing CAT ECUs (which by the way yours are new) and much more, I decided to replace the thermocouples and tah-dahhhh.... no more false slow down light!! It's as if these things get so smutty that they lose their sensitivity when exhaust gases are moving slowly. Drive hard and get things heated and flowing and the slow-down light goes out. My joke to myself was they should rename the indicators to "speed up" indicators --Nick
Nick My car did the same, when it's left to idle or moving at a slow pace for a while, the Slow Down light will flash. All it needs is speed up and the light will go off. So, like you said, speed up instead of slow down next time when a light throws up. Regards
Yes, Nick, I figured out the "speed up" secret for my (our) car. Of all the good things about the car, and F-cars in general, the electrics are crap! And I thought my 1970 MGB with Lucas stuff was bad.
I also have this problem with my '97 550. Low mileage cannot cause this problem, mine has 156.500 km under the belt At first I thought it might have something to do with the petrol, but changing brand didn't resolve the problem. The slow down at first came only when I did speed up, but now it also lighted up right after storting the engine. In a month or so I will lift the car for renewing the brake hoses and pads and I will check and clean the connectors. Let's see if this helps, let you guys know as soon as possible.
