Alfa Romeo 4C Forums banner

Transmission Issues in 2021

10327 Views 66 Replies 15 Participants Last post by  gkardr6
Title: Transmission Issues in 2021

Hey all,

I've been experiencing transmission issues similar to those that others have had in the past, and am hoping for some help to understand how to diagnose and fix these problems. I've had the same issue three times in a month now:
  1. I drive the car for a while with no issues (the first time I had been driving the car for about 3 hours, the second time I had only driven it for about 30 minutes)
  2. Park the car and turn it off for a little bit (the first time this was only a few minutes as I filled up for gas. The second time the car was off for ~2 hours)
  3. When I go to restart the car I get the "Christmas Tree of death", reverse and manual mode are not available, and only 2nd, 4th, and 6th gears work. The first time this happened the car actually got stuck in reverse for a bit before it finally went into neutral, but then couldn't go back to reverse or into 1st/3rd/5th.
  4. No amount of key on/key off/reboots changes anything. If I pull the negative battery terminal AND let the car sit about 30 minutes, it will suddenly fire up just fine. All the warning lights go off except the CEL, all gears and modes are available, and the car shifts just fine. After driving for some amount of time, the CEL also clears itself.
  5. The third incident occurred while driving this morning. On the freeway with the cruise control engaged and car in auto mode, the transmission light briefly flashes, CEL illuminates, I get a bunch of warnings, but the car continues to shift fine in auto mode. Once I parked and turned it off, it now has all the same problems as in #3 when I try to restart it.
After the first occurrence, I took the car to the dealer and they could find nothing wrong. They double-checked the software was up-to-date (I even provided the number of the SW patch below) and confirmed there was nothing available. They then quoted me $9,000 to replace the transmission, so I took the car back and decided I would have to solve this myself.

To start, I've read all of these threads:

Transmission Failure
Transmission Failure Poll
Heads Up On a TRny Issue
Inconsistent Problems: “The Christmas Tree of Death”.

The problem is that the majority of the problems people had occurred early on, and dealers either solved the problem with a software patch which predates the build date of my car (I have a 2016) or they replaced the transmission. My car is out of warranty so a trans replacement "just in case" is not in the cards.

From what I can gather, these are the possible sources of the problem. Is this list complete and in which order should I troubleshoot this?
  • Clean/brush battery terminals and add dielectric grease - already tried this after the first incident, didn't solve the problem
  • New battery - I tested the battery at Autozone, they claim that it's totally fine, not even marginal on startup
  • Get the software patch that worked for others (CFC8TDW.01-00-UF14M080) - I gave this number to the dealer and they claimed everything is up to date
  • Check/refill "Robot mechanism" (shift actuator?) fluid level
  • Replace shift actuator pressure sensors with this part: Pressure sensor - Alfa Romeo TCT - SequParts
  • Replace voltage regulator for shift actuator
  • Replace hydraulic actuator p/n #68303710AA
  • Replace transmission
Also, is anyone aware of an Alfa tech or indie shop somewhere in the US who actually has experience troubleshooting and solving these issues? The tech at the local dealer had seen this problem many times on Fiat 500Ls, but said that they just R&R the transmission every time, so he didn't have any idea how to diagnose the root cause.

Any help would be appreciated, I don't feel like I can trust my new car enough to drive it anywhere until this gets sorted out.
See less See more
  • Like
Reactions: 1
1 - 17 of 67 Posts
Hello, My name is George from Greece and I own a 2015 4C. I have the same promlem with transmision. I already 35.000km. After driving 45km the gear box goes to safe mode and I can the car goes to auto and use only the 2nd 4th and 6th gear. when I go back home and leave it all night, the next day its everything fine! I drive about 50km and the issue appeared again! do I have to change all the transmision? The failure coed is P0914 any ideas
I have already read all the post so I change battery and the problem still exist!
  • Like
Reactions: 1
Thank you very mush for your response! the batery is new! So I have to check the sensors?
Ι will try and I give you a feed back!
Thank you very much!
  • Like
Reactions: 1
thank you very much! I will talk with my technisian!
How do you explain that when the car is get started is fine, and after 45km begins the problem?
Ηοw can I check if I have the last update in my car?
Is it possible the problem to become from the software?

also the last time of the problem the gearbox has a difficulty to change the gears
Hi again,

the mechanic dies his best and check everything! During the tests the transmission is getting worse!
When we strart the car and i don t have any issue, the car the gearbox can t change easy the gears! It has many delays!
so, maybe I have to change it!
do you know which is the latest update version?

the problem is that the trasmission is getting worse afterwe check something!
It doesn t change the gears easy! May be the problem is the clutch and not the robot!
We have done everything and now i take the car to test it! I dont feel to have problem with the change of gears! The battery its ok, we clean everything and we change the liquid!
the previous time i testedthe car, it was ok for about 200km and then the problem appeared again!
Also i dont have problem to change the gears from 1 to N to 1 to R.
How many km I have to do in order to understand if the problem fixed or not!
my 4c doesn t have the air taken fir the gearbox which Alfa Romeo put it in newer models! I am afraid if the problem was the temperature of the gearbox! So I test the car without the cover of the back wheels!
Oooops I didnt know that! I have to ask the mechanic again! I drive 130km to D and manual! I dodn t have any problems yet!
I have drive for 170km with no problems!
Ps I haven t put the covers of the rear wheals an the cover under the machine in order to reduce the temperature!
  • Like
Reactions: 1
Thank you very much! We will see in few km!
We change the oil and we check the battery and I check the car!
I have done 600km with no problems
  • Like
Reactions: 2
1 - 17 of 67 Posts