SDL with new hyperflows, new rear o2 sensors, changed oil and reinstalled right temp

Sorry, I only read John's summary. If you are absolutely sure of the TCU outputs then your problems have to be in the Motronic ECU and it's output to the SDL or in the wiring/connections before it. The 1.5V battery test is a way to absolutely without question take those 4 items out of the equation force feeding the Motronic what it wants to see to keep the SDL off. It's like a difficult to diagnose cracked tooth. As dentist prepares it for a crown a cusp falls off. Diagnosis unequivocally confirmed. Mitchell is a smart guy, 355 owner and Norcal troubleshooter with history of unraveling significant fellow owner issues. If you are absolutely sure on your end then I'm going with his guess too.

One of the primary reasons for the SRI gold kit is to stop the "ghost busting." In the past there have been many threads such as this one. If you come to the conclusion that it is the wiring consider the commercial gold kit or a variant depending on who you believe and how must risk you are willing to take. Once you start taking a hard look at Ferrari wiring you will appreciate efforts to improve it.

 

I chased a similar issue. Double check that the TC's and wires on the R/H side are done correctly. Mine had them reversed and it drove me nuts for the first summer I owned it. Par for the course considering the repair facility I got the car from.

To check the by-pass valve,pull the vacuum line and attach a speed bleeder to the valve. Pull the trigger and make sure the valve moves.

 

Great. That eliminates the TC as the problem and that pretty much says green TCU is bad. What I would do next is to switch the TC connections back to normal and then switch the connections (TCU output) to the main ECU for the same black and green TCUs. You should still see the output of the black TCU rise and the green stay flat. This would confirm that the green TCU is bad.

[edit] if the black TCU still functions this way it also indicates that the main ECU and wiring are OK.

 

In my mind yes. You could test it with your car to by fuddling with either the TC or TCU or wiring to. That's what throws that code. So if he is getting it answer is
TC
TCU
wiring
Motronic

If he eliminated the top 2 as a possibility....
I can just about guarantee if Bob takes off his Motronic connector plug and looks carefully he will be shocked at all the spread open pins. I have never seen an OEM Ferrari plug of our vintage without spread pins and I have seen too many to count. I'm not saying that's the cause in this case but it is indicative of Ferrari electronic quality. Only time will tell if the improved SRI gold pins will maintain their suitability. I'm about 3 years out on a prototype gold kit and those pins are still tight and closed from my actual visual inspection. I pretty skeptical so I check and I beat on things and so far I'm pretty impressed. Controversy abounds as to method of fix for Ferrari wiring. One thing for certain something needs to be done. Even the early days of stabliant -22 and bending pins bought us temporary relief until better solutions could be developed.

 

Yup

Just did a 355 where it stopped sending signals to the OBD plug

Bad connections at the ECU, like fbb and others state I have not seen a perfect plug yet (factory)

 

Don't need to guess Bob.

Row 1 pin 14 Lite Blue, Thermal TCU Bank 1,
Row 1 pin 15 White, Thermal TCU Bank 2

test the continuity between ECU pin 14 and TCU output bank 1 (pass side)
The other one on the passenger side, must be the center TCU for the bypass valve.

 

Check your new o2 sensors, you may have installed the front o2 on the rears

 

Dr I have a 5.2 ECU spare

Also wiggle your wires, sometimes they can break or frey where they go through the firewall

 

so the compilation of your experiments is:

No matter where the black TCU is plugged in, left right or center, it is the only one that puts out voltage higher than 0.55V.

Does the CEL error also follow the black TCU?

 

Sounds like maybe a front O2 sensor in the rear.

That just sounds wrong.....

 

FWIW, I found this. Exhaust Gas Technologies Inc. - Motorsports Catalog

We need a Ginny pig. Bob?

 

Oh, and for those constantly complaining about these "355" problems, http://www.ferrarichat.com/forum/360-430/449154-my-first-slow-down-light-%3D.html. Please note the forum.

 

OMG! John if this works and is robust this could be the best find in a decade helpful for a wide number of Ferraris. We need to try this.

 

No. If you down load the specs it says it will work on ant source from 5 to 30+ volts. 14.5 is recommended only if you want to use it over its full range, up to 1250C = 2282F.

The only potential problems I see are 1) it doesn't output 0.5V minimum which might be required in a Ferrari to tell the ECU that the TCU is connected on cold start, and 2) based on its voltage gain it looks like it might push the SDL trigger poits a little higher in temperature. I don't think 2 would be a problem. 1 might be.

 

It looks like on of the parts we use with our kiln controllers. Thats a great find for sure

 

John by eye this EGTech unit looks to be a direct swap to the Ferrari SDECU See graph of their PDF page 4 and john's post in my thread http://www.ferrarichat.com/forum/140746813-post28.html