355 F355 Unusual shifting issue

Could be many problems
Need more info
You need to try various things
Read some of our symptoms in the past.

My guess would be engine mounts are bad and actuator is hittting cross member. It can do this with good mounts but good mounts would indicate a major was fairly recent.

 

You should be able to shift through all gears with engine off

I assume your speedo is good and reading properly
Does your transmission light flash when driving?

 

You realise that a vehicle speed signal is essential for proper F1 operation? You could get out of this relatively cheaply if you can figure out if you have a speed sensor problem or speedometer problem (the speedometer processes the speed signal before it sends it to the F1 TCU). Having said that, the engine Motronic ECU and the suspension system also uses the speed signal. You don't also have a Check Engine Light or suspension warning light?

 

Do you have access to an oscilloscope?

http://www.dinoplex.org/instruments/vegliaspeedosensor/

Here's how to replace the speed sensor if required

https://www.dropbox.com/sh/kufk5c92mfqd50n/To1XNeSKVT/Ferrari DIY?preview=F355+Speed+Sensor+Replacement.pdf

There are different ways of removing it. It depends on whether you have access to the underside of the car or not. Tooling requirements may vary depending on how hard the sensor is screwed into the gearbox case.

 

I guess you have no OBDII reader. That would tell you if the speed signal is faulty or something else.

I'm not sure why you're not getting a suspension system light. Maybe the suspension ECU only logs a speed signal failure without putting on the light. Anyway, my money is still on the speed sensor or speedo. Check the plug on the sensor for contamination. You may be able to access it from the top by removing the small heatshield above the left hand axle boot. The heatshield is held on with two nuts.

 

All 355's do this.

Well, that does seem to confirm mine (and others) suspicion about a faulty speed sensor. Internal gearbox failures have affected the speed sensing system, but we don't want to go there just yet Why it came back to life, I don't know. Has anyone heard of metallic sludge in the gearbox causing signal interference (and subsequent oil warming loosening the sludge)?

On the other hand, Grant (Taz355) does seem to think you should be able to select all gears with the engine off. Does this exclude the speed sensor signal?

Curiouser and curiouser indeed. Anyway, I would invest in an OBD scanner (with Fiat 3 pin adaptor) and a new speed sensor (these commonly fail).

 

Sorry, I don't know where you're located. If you're in the USA, you won't need the 3 pin adaptor.

 

I do not know for sure if once the speedometer gives a fault weather the transmission saves the fault. I believe it does but not sure.

The transmission will definitely shift through all gears when car is off if everything is working as it should.

One thing at a time so fix the speedo which is likely the sensor or sensor wiring. Once that’s good then we can continue.
As for the suspension light I would not worry about that until f1 is working as it should.
I think you could start your car and if the transmission light is flashing as soon as it starts it definitely has logged a fault and knows something was wrong earlier.

If Speedo fixes the problem great but if not I would then have someone shift the car while engine off and watch actuator and see if any obvious binds in linkage are happening.

 

If you, at any point, shut the car off while the wheels are still moving, it will screw up the sensors signals.

I have posted this so many times you would think I would just have a link to this:

With the car off....
Put your foot on the brake and hold it.
Move the key to position II (DO NOT START IT)
Count to 5
With your foot still on the brake, move the key to off
Count to 5
With your foot still on the brake, start the car.
This will "home" the sensors again.

As others have suggested, your symptoms seem to suggest either a bad sensor or a bad speedo.

My speedo died and I pulled it out and resolderd all the solder joints. That fixed it.

 

Speedo problem like all things can happen just not as often that I have seen. But as usual your absolutely correct.

 

Good to know.

Just wondering what's sensing the "wheels still moving". If you shut off the engine, the speed sensor has no power. Anyway, I guess if you were doing checks on the speed sensor by spinning the wheels, it wouldn't hurt to do an F1 sensor reset.

 

I shut off the car with the wheels moving but I think he meant in gear.

I had a oil plug come loose and started loosing oil pressure I shut the car off and then coasted over 5 miles down hill to a pull out.
I had too leave key on for headlights because it was moderately dark.
Car was in neutral though

This did not effect the f1 system at all. Filled car up with oil and everything worked fine once I restarted engine.

 

Not sure actually, But section H page 29 of the owners manual has a discrete reference to it.

The full prcedure was one I picked up from either Lakeforest or Bradan (don'l recall who) and it fixed some really weird shifting anomalies I was having.

The cure-all for my system was the swap out of the accumulator bulb. That fixed every little thing and shifts like a champ now.

 

Yikes. That would be abrupt!

I stopped my car once while rolling to a stop in in neutral. It did not like that at all.
In fact it would not select first gear when I returned until I did that reset.
I remember it like yesterday because it was right in front of a little restaurant....and I was sitting there reading the manual. *facepalm*

 

Yes I guess it would never thought about that but def would not work out well
Nice correction