Difference between 5.2 ECUs

Anyone know the difference between the earlier ecu

Ferrari 355 (5.2 Motronic) - CONTROL UNIT IGNITION
Part No. 168600
-Valid till Ass. Nr. 26746 - Not for USA, CDN, AUS, SA and ZA - Valid for ABS BOSCH J, CH, and S cars - Not for 355 F1 cars

and this later one?

Ferrari 355 (5.2 Motronic) - CONTROL UNIT IGNITION
Part No. 176224
-Valid from Ass. Nr. 26747 - Not for USA, CDN, AUS, SA and ZA - Valid for ABS BOSCH cars - Not for 355 F1 cars

and more significantly, will the later one work on an earlier model?
Main reason being it is half the price!

 

Just been told they are not interchangable. There is a difference in all the electronics they each control or get signals from.

 

I also have an F355 spider with ECU number 168600 and it appears to have gone in to safe mode. It has done this before and I changed one of the Cat sensors and it solved the problem. I've now changed the two sensors for 2 new ones but how can I get the car out of safe mode without having to take it to a dealer, which is a good 2 hours drive away. Any suggestions?

The car starts and runs, but you can tell its in safe mode. I have tried turning the battery off for 24 hours to reset the ECU but its still in safe mode. When the car goes in to safe mode, what does happen as all pistons seem to be firing ok. All 8 spark plugs are also firing ok Is it something to do with regulating the fuel to the injectors?

 

What year spider.? #168600. Remove fault codes should turn safe mode off and also would identify what caused the the reason or reason's for the ecu switching to safe mode

 

What are you guys calling safe mode.
The sdl is litup or flashing??

 

SDL possibly not on. Not a100%sure with Ferrari. I'd say check engine light would be on solid not flashing. Mine has always gone out after engine starts. Most cars when in Limp or Safe mode have the Check Engine Light on or flashing continuously. Someone on here should be able to help there's plenty of experienced people on this forum

 

Back to the ECU 's, my 97 euro spider runs on both the Original ECU (europe) and on the ECU for Japan etc.
No CEL or SlowDownLight on both.
I do not know what the differences are. They simply both work for my car.

When the ECU is in safe mode, that means SDL is on solid, one bank does not fire, hence you only have a 4 cyl car.
Do not drive it that way! Very bad for the cranckshaft (I do not understand why Ferrari made a safety net for the engine by risking the engine...)
When the cause (often in the CAT Ecu's) is gone, the car would run on all 8 again.

Except when there is something else wrong, and you do not have a SDL but a CEL.

 

That makes no sense at all. My understanding is that an SDL is telling you that the catalyst system is overheated. An engine light tells you there is another sensor or system that has malfunctioned. Safe mode allows the car to have limited use but not function as if all system checks are working correctly. EXAMPLE. SDL light comes on failed cat or O2/thermocouple sensor. When car cools down SDL goes out BUT check eng light will be on due to a logged fault code in the ecu.

 

Not the whole story but true
Also true solid sdl car should not be driven far.

 

I have had SDL's on my car because of swapped O2 sensors. In the end the car started from cold with a blinking SDL (with the cats stone cold !!!) and within a mile it would light solid, with cats not even at half there normal temperature. And a 4 cyl car as a result.
When restarted, the sdl would blink again, and all 8 cyls were working for a minute or so.
When I finally found what a previous owner/garage had done with the sensors, it was rather easy to rectify.
When the car ran again, no SDL anymore.
In this whole story I have not once seen the CEL on (only on ignition).
So it is not true that the CEL is on after the car is back on 8 cyls.
However it will be if there are other problems than the cat system, but that is another story.

 

Yes I agree but as your post states the O2 sensors were not correctly orientated so that was the issue. My explanation was regarding the whole system working as it should. If a SDL light comes on then it should be a catalyst system issue which is totally separate from the CEL.

 

Agreed the system must be working prior to the problem and not a mixed up system that was never setup to work corrctly.
My understanding is same.
Sdl is cats
Cel is emmisions, ie o2. Secondary air, etc

 

The car is a 1997 model. I've had an OBD2 reader on it and there's no codes showing. I can ell the car is in safe mode as I've had this problem before. On one occasion some years back, when the car cooled down it reset itself and the problem went away.

 

The engine sounds lumpy on tickover, and when I drive it there is much less power. The CEL is on when the ignition is on, but then goes off when the engine is running. Very grateful for any help you guys can give.

 

The workshop manual seems to omit the details relating to safe mode, but perhaps ignition is affected on one bank during safe mode. Since no faults are shown on your OBD2 reader, and you have ignition on 8 cylinders, then perhaps it's not safe mode. Perhaps it's a faulty fuel supply to one bank (e.g. fuel pressure regulator). Perhaps your local service centre might show a little sympathy (since you are two hours away) and offer some information on this?

I can't recall if the SDL also triggers the CEL during safe mode. Is your SDL also operating with the ignition key in ON?

 

Derrick this is a 97 obd2 355 correct?
If it is
Does you sdl come on at ignition key on but not started if yes
Plug in obd scanner and look at misfires and fuel trim.

Also you said you replaced cat sensor.
Did you replace themocouples or O2s and if O2 s which ones front, back, both.
If thermos which ones

Also is your idle control valve plugged in and installed correctly.

 

Prolonged SDL light will cause a CEL, protection circuit bank 1 or 2

 

Yes but whats bugging me is he said no sdl?
Still only running on 1 bank maybe? Or just a bad idle, missfire, or bad injector?

 

If it's only one bank I'd check the coil itself. In my experience they tend to work ok when cold but as the coil/eng warm-up they can give trouble. Even run for a few minutes then start to misfire. Another item that is often forgotten about is the ecu coolant temp sensor. This item never really gets changed and if giving a faulty signal to the ecu can cause all sorts of dramas and wont give a fault code. O2 sensors can do the same. I really can't see that the ecu could be in safe mode without the CEL on that makes no sense but happy to be proven wrong

 

A timing light on each lead individually can tell if it's a coil issue. As can a LED test light to check voltage at the injectors. If theres power at the injectors and spark but misfire it's a plug or injector due to either fould plug to much fuel or a lean misfire due to faulty injector

 

Also what brand and type ODBII reader? Seems a silly question but is it actually connecting to the ecu? Does the code reader say. !Connected to ecu!???

 

I do nit think the op has tried an obd reader. That was why I suggested it. This will tell them if it is a misfire, or possibke some other issue. If the misfire continue for long it will set a cel due to emmisions

 

Very grateful to all of you for your advice re: safe mode. The car is now mothballed for the winter at the moment, but as soon as I get time I shall get back and investigate the problem and take on board your advice. The OBD2 reader connects to the 3 pin ECU connector and seems to work fine as it gives live readings etc. The fuel regulator to 1 bank could be a strong possibility as all 8 plugs are sparking ok. I shall also change the fuel filter and take it from there. One thing I have done is disconnect the injector lead one at a time to see if it has an effect on idle. Standing at the back of the car all the 4 on the right had a noticeable effect, whereas on the left they didn't appear to have such an effect, so this could again point to a fuel issue. Will also check if the SDL is on or flashing.
I will get back to you all with any updates! The car is due back on the road by April, so I do have some time to have another attempt to sort the problem.

 

Please advise on brand of ODBII reader used and what yr car 96 97 etc

 

The car was manufactured in 2007 and first registered in June 2007.
The OBD2 reader I use is a Vgate MaxiScan VS-890 and have a special lead that goes to the 3 pin connector on the car, which I bought on eBay. There are also 2 wires that come with the lead that connect to a 12v battery, but you must change the polarity of the 12v lead and then you will find it reads.
When I get round to having another look at the car, I am now quite confident that the fuel pressure is low feeding the left bank.