[rikiduc]

The attached document provides a description of the experience that I gained during the search for the root causes of errors that can arise in the TCT of the 4C.
It ended up being a 24-page document.
Questions, constructive comments or suggestions are very welcome, but please read the document in its entirety first.
The references to pages in the service manual are the PDF page numbering. This may differ depending on which file and version you have.

Have fun reading and I hope this helped you a little bit ?

 

[Gilly]

@rikiduc great write-up! It’s wonderful that we have passionate and knowledgeable owners such as yourself that are willing to invest the time and effort to share this knowledge for the benefit of all owners!

Have you also considered shorting or bridging faults on the TCM module as a potential failure mode? I have seen examples of such hardware failures that then present as intermittent functional faults. I note that many of the early model 4c did not have rain covers fitted over the TCM modules and wondered if this was added as result of a factory root cause analysis.

 

[rikiduc]

I made a cover for the tcu module myself for better protection against water. the connectors are of very good quality but the cabling itself is not that good. I have re-insulated all cable ducts in the engine compartment with tape. the later models may have been modified from the factory

 

[rikiduc]

To add:
Beforehand I first checked all HW and electrical cables. All cables, especially under the battery, have been re-taped and additional protection has been applied. A protection plate in aluminum was placed in such a way that the electric control module of the electric motor is better cooled

 

[KarlB]

Maybe dumb question.... but why not just slather di-electric grease over the areas of concern?

Or is it too hot in that area and it would liquify and run off?

Thanks,

 

[rikiduc]

it's too hot there and not a reliable solution, too quick and dirty...😗🔥

 

[OriginalForza]

I can confirm later cars had a harness revision, I will likely go crazy trying to find that PDF but when I do I will edit this post. It's not obvious but the later 2015's have twisted pairs under more plastic cable rather than the varying degrees of hasty taped bundles of earlier cars. Then, as of maybe 2017/2018, the shield/cover solution was added, slowly retro fitted to earlier models that came fourth via TSB/service. From what I've gleaned years ago when my TCU failed, it tells a story of how the factory learned chassis lessons, when paired with the 8c's story, and even the Maserati Granturismo, becomes crystal clear. Reading through your bulletin brought back whatever memory on how I feel the factory engineers made lemonade from the lemons the executives and bean counters threw at them to resolve. The 4c story is as organic as the car! What's funny is there seems to be a serious team/brain change from the Enzo/MC12 to the 8C, where the "MCS" ended up tested even by Schumacher to death, while the 8C was more "Granturismo Bodykit" (but still very much it's own car versus the larger, heavier Granturismo), and then the 4c being 8c habits passed unto a midengine carbotub Frankenstein.

If the 4C had the resources the MC12 had (and Schumi to beat out the proverbial slag), it would have driven more like it looks, punching unrealistically above it's weight, and likely costing a little more, maybe a $75k+ msrp for the coupe. Just a fun feel on alternative history. Now those characteristics are up to us, which if enthusiastic, is a pleasure to take the final yard. For all the complaining that can be hurled at the 4c we got, it can be silver lined by seeing it as a discount to tune to one's own final finish rather than the factory's... And that's pretty cool in an era where the chauffeured government has more say in what a car is than a tenant and mastered automobile manufacturer.🍀

Now... Anyone down for a group consignment of a Rywire mil-spec harness and Motec processor swap?🤣

 

[Alfanut]

I can confirm later cars had a harness revision, I will likely go crazy trying to find that PDF but when I do I will edit this post. It's not obvious but the later 2015's have twisted pairs under more plastic cable rather than the varying degrees of hasty taped bundles of earlier cars. Then, as of maybe 2017/2018, the shield/cover solution was added, slowly retro fitted to earlier models that came fourth via TSB/service. From what I've gleaned years ago when my TCU failed, it tells a story of how the factory learned chassis lessons, when paired with the 8c's story, and even the Maserati Granturismo, becomes crystal clear. Reading through your bulletin brought back whatever memory on how I feel the factory engineers made lemonade from the lemons the executives and bean counters threw at them to resolve. The 4c story is as organic as the car! What's funny is there seems to be a serious team/brain change from the Enzo/MC12 to the 8C, where the "MCS" ended up tested even by Schumacher to death, while the 8C was more "Granturismo Bodykit" (but still very much it's own car versus the larger, heavier Granturismo), and then the 4c being 8c habits passed unto a midengine carbotub Frankenstein.

If the 4C had the resources the MC12 had (and Schumi to beat out the proverbial slag), it would have driven more like it looks, punching unrealistically above it's weight, and likely costing a little more, maybe a $75k+ msrp for the coupe. Just a fun feel on alternative history. Now those characteristics are up to us, which if enthusiastic, is a pleasure to take the final yard. For all the complaining that can be hurled at the 4c we got, it can be silver lined by seeing it as a discount to tune to one's own final finish rather than the factory's... And that's pretty cool in an era where the chauffeured government has more say in what a car is than a tenant and mastered automobile manufacturer.🍀

Now... Anyone down for a group consignment of a Rywire mil-spec harness and Motec processor swap?🤣

The MY16 cars were the first to get the TCU shield. Mine has it, built in Dec 2015.

 

[arianarad1994]

The MY16 cars were the first to get the TCU shield. Mine has it, built in Dec 2015.

i have not read the PDF file yet but in brief it means the solution is to add a tcu shield and everything will be okay? or there is still more other things to be afraid about with my 2015 LE EU-version?

 

[rikiduc]

dear all,
I am going to remove the photos from the protection plate and the cabling because this discussion is going completely the wrong way and has nothing to do with the original subject. If you are interested in the subject, please read the full PDF document first. Thank you

 

[rikiduc]

The attached document provides a description of the experience that I gained during the search for the root causes of errors that can arise in the TCT of the 4C.
It ended up being a 24-page document.
Questions, constructive comments or suggestions are very welcome, but please read the document in its entirety first.
The references to pages in the service manual are the PDF page numbering. This may differ depending on which file and version you have.

Have fun reading and I hope this helped you a little bit ?

 

[OriginalForza]

The MY16 cars were the first to get the TCU shield. Mine has it, built in Dec 2015.

Mine as well, but it didn't have it, built October 2015, like my friend's Feb 2016 built, which also didn't have it. When my TCT failed, skipping gears and limp mode, we took a look at his. When I got mine back with the shield, his didn't have it. He took it in, they said "nothings wrong, it's good, but if anything happens we will tow it here free" and lo and behold: shield. Dealers/AR was slick on some of these maybe, but certainly for a 2016.

 

[Alfanut]

Mine as well, but it didn't have it, built October 2015, like my friend's Feb 2016 built, which also didn't have it. When my TCT failed, skipping gears and limp mode, we took a look at his. When I got mine back with the shield, his didn't have it. He took it in, they said "nothings wrong, it's good, but if anything happens we will tow it here free" and lo and behold: shield. Dealers/AR was slick on some of these maybe, but certainly for a 2016.

That’s really interesting. The 4Cs for each market were made in specific batches. For example when I ordered mine, if I missed the order cut-off date I could have been waiting a further six months or more until the next Aussie batch order was made. It couldn’t have been that they just didn’t have enough of the shields at that time, could it? I wouldn’t be surprised. Is it Gilly or Knievil who has the lightweight hatch without the lining, so anything is possible.

 

[rikiduc]

The starting point is of course that the wiring is completely ok, but I can assure you that the addition of a protection shield on the TCU is a good idea, but NOT the solution or fix for many TCT problems.
You really need to focus on the TCT as a complete unit. Meanwhile, I can confirm that the latest SW update and a revised robot, a complete new callibration, fixed the issues.

 

[Alf Alpha]

@rikiduc Thank you so much for your very detailed pdf Erik.
It helps to be able to picture in your mind how these things work together and your photos and write up have helped me grasp a better understanding of this complex unit.
Cheers,
Alf.

 

[rikiduc]

Thanks!