My speedo died today. All kinds of fun things happened after that. 1. My F1 car will not shift past 2nd gear 2. The gearbox warning light is on. (start off, but turns on once the car starts moving and no speed is sensed) 3. The suspension light is now on I don't think it is the speedo itself, but it could be. Which sensor kills the speedo? This one: https://www.ricambiamerica.com/162916-sensor-speed.html Or this one: https://www.ricambiamerica.com/car-diagrams/ferrari/v6-v8/355-group/f355-m5-2-1996/gearbox-covers-and-lubrication/149095-sensor-speedo.html
????? No clue, but that’s an odd list of things to appear at the same time. Having a MT everything with paddles just baffles me Hopefully one of those (cheap) sensors will fix all that.
The second one, mine did this as well. Get up to speed in 2nd then hit neutral, then the downshift paddle, it should go to 6th gear. You should be able to down shift as you wish from there to limp home.
Not odd. The speedo feeds all those systems. Was the Check Engine light on, too? Replacement tutorial here: https://www.dropbox.com/sh/kufk5c92mfqd50n/AABQnT5MSW3R2UiMRKvZkoNfa/Ferrari DIY/F355 Speed Sensor Replacement.pdf?dl=0 If you want to do a Stooge repair on the "Type 2" sensor: http://www.dinoplex.org/instruments/vegliaspeedosensor/ Instructions on how to check Hall-type sensors are also included in the above.... recommended before you buy a new one, as it could still be a faulty speedo. The speedometer processes the signal from the sensor and then sends it on to the other systems.
Wiring diagram here: Instrument Wiring Diagram (5.2) There are a few connectors between the speedo sensor and the speedo that you could check: The connector on the sensor itself The 12 pin connector behind the left hand rear shock. "41019" The white connector forward of the centre console "41024" The connector on the back of the speedo. There is a power fuse, but you would have a lot more instruments failing if that was blown.
As already stated here, it is the second one you posted, an overall easy change out. Mine went a few months ago: https://www.ferrarichat.com/forum/threads/f1-overhaul-thread-clutch-pump-throwout-flywheel-360-pump-etc.467896/page-4 When you extract it, see if it has the same hairline split mine had, I wonder if it is generally the same failure mode.
Excellent help. Where is the above connector located? I had the dash pod out to fix some leather issues....did I miss something??
41024 is well away from the instrument binnacle. Perhaps the connection on the speedo itself is not connected properly? Or needs some DeOxit on the contacts. For info... here is 41024: https://www.ferrarichat.com/forum/threads/seatbelt-warning-light-cabling.525227/#post-144748652 (Top photo, post #3)
Note that sensor replacement can be done without removing the wheel and inner guards if you're lucky. If not, you may need to remove the wheel, guards and fabricate a special socket. If you know 100% that the sensor is broken before removal, you can always cut off the electrical plug and use a standard socket.
I cleaned up the back of the speedo connector and the wire harness connection. But that did not fix the issue...and now the suspension light. Hummm If the speedo itself crapped out, would that matter to the TCU? It does get the speed input from the sensor not the speedo. Right? Now that I look at my repair records, I replaced that gearbox speedo sensor about 8 yeas ago. Not that big of an effort. I even have the socket with the notch in it. Can it crap out that fast??? I know... I shall pour a glass of brunello and think about this....
No, the speedo processes the signal from the sensor (dividing the frequency in two), then sends it to all the other systems via splices on a white wire (with yellow stripe). See diagram link above. I'll have to have a look at the Workshop Manual to remind myself what the TCU does with the signal.
Well, it could mean that your speedo is broken. That's why I suggested testing your speed sensor first. If you know someone with an oscilloscope, you may be able to tap into the signal without removing it, but this may be impractical to do this because the car has to be moving to test the sensor properly (with the oscilloscope plugged in somewhere). Probably the easier way would be to remove the sensor and check it (as per the Veglia/Borletti tutorial). The sensors are prone to damage because of heat in that area. Yours may have failed again.
Where is this thing located in a 355?? ...if at all??? https://www.ebay.com/itm/Ferrari-Speedometer-ECU-348-355-512-Testarossa-VDO-OEM/150564038440?epid=1177261895&hash=item230e50e728:g:hlUAAOxy14VRQYXl Image Unavailable, Please Login
Doesn't look familiar at all since the ad states for the 348 as well. However, another ad with an almost identical item calls it the "360 Spider Shock Absorber Suspension Module" https://www.ebay.com/itm/2004-Ferrari-360-Spider-Shock-Absorber-Suspension-Module-Box-Computer-VDO/323111983135 Image Unavailable, Please Login
Huh... Thanks for that. I know these cars pretty well and do not recall seeing that box anywhere. BUT....I don't know it all so thought I would ask.
VDO? I guess you're already looking for a speedo, Watson. Don't fret. 9 times out of 10 it's the sensor. I don't know if there are any message threads on repairing 355, but there's a good one here on the 348 speedo repairs https://www.ferrarichat.com/forum/threads/348-speedo-burned-internals.503511/
The AC System fuse, but then all your instruments would not be working (apart from the clock). The suspension light would not illuminate if this fuse was blown. Also, the suspension light would not illuminate if this fuse was blown (and possibly the gearbox light)
Ugh.... I've seen the price of new mph speedos. About 2~3 times the price of kph speedos. Did you test the old sensor? Also, it might be worth doing a few wiring checks. e.g. The fuse will be ok, but do you have 12 volts at the speedo plug on the sensor's green/white wire with the ignition on? You can also check for volts on pin 2 of the 12 pin plug near the top of the left hand (rear) shock strut. There has been a case of the reluctor in the gearbox coming adrift on F348's https://www.ferrarichat.com/forum/threads/348-mystery-part-on-transmission-magnetic-plug.576834/#post-146022289 On the bright side, at least you don't have a F348-style mousetrack seatbelt system which can blow up the speedo.
Thinking it is a wiring issue.... I messed around with the two connector blocks you mentioned (mainly the back one) and then tried again. Now, the suspension light is off....? But the speedo does not work. Gah! I have to go study your wiring diagrams and see if I can check the voltage at the speedo as you suggest. Thank you for the help.