DCT overheated - Solved?

[Helmsman]

Edit April 19th'24

Quick update. Started to collect some more data since I got Protool.

I have not yet reset adaptation but compared some clutch pressure etc data with another box (Redd, who have re aligned with Protool) and there is nothing that looks strange. I'm hesitant to re align the clutches without clear reasons as the action is irreversible.

Reading the temps it is the "Clutch oil" sensor that goes up while the others are stable. From pictures I've seen this sensor is located on the upper side of the clutch package. According to some BMW literature the clutches are cooled by a "oil spray". I have no idea what this looks like inside but thinking MAYBE this spray need a bit of rpm and action to function properly. With this in mind, when the temp clutch is raising (going from say 85-95C to 110C and above) I simply started to rev out and shift "hard" in setting 5-6. This actually seems to bring down the sensor temp.
I plan to have the box topped up should one reason be a tad low level (changed the fluid 11k miles since)

Happy if anyone with more insight in this sensor location, and how the cooling spray works could chime in!


Edit Aug 3rd'22:

Quick update on this thread;
After replacing below mentioned aux water pump a number of weeks ago the DCT over heat code has not come back. I certainly still feel the heat when touching the oil/air cooler but again no code. Very happy as I've had it sporadically over the last few years followed by limp mode (where I also believe I started to to get the pump failure code).
Anyways, though I mention it as the DCT heat code is fairly common out there.


Hi guys,

general reach out to the guys who had issues with DCT overheating.

I've had the DCT heat code (5A53) sporadically over the last couple of years. Fairly fresh box and typically in stop/go traffic so never really believed in actual overheating but a sensor issue.
In parallel I’ve had the aux pump code (A6D1) coming and going to eventually stay. Didn’t bother too much as I don’t have the “rest heat” in my 2011 car, for which I thought was the main/only function for this pump.

Anyways, reading through some DCT doc the other day I realize the aux pump also help providing coolant to the DCT not only for warm up, but potentially also for cooling/stabilizing the DCT temp, which made me very curious.

Anyone out there with some experience with regards to the aux pump/DCT overheating?

Doc I'm referring, page 12-13 and 45-47: https://www.m3post.com/forums/attach...4&d=1317583307

Cheers,
Nik

Ps. According to the dealer my car/VIN is not even suppose to have the aux pump at all, but it clearly does.

[noremaC]

Any physical symptoms when driving with the 5A53 code? Clutch slippage?

I'll share my experience from last fall:

I had this code pop up (5A53 = Phase Red, DCT Oil Temp >160 C) last year and ended up putting in a new (used) DCT. There is also a 5A54 code = Phase Black, DCT Oil Temp > 170 C. Not to scare you here just sharing my experience.

I got first the Transmission Overheating (5A53) warning when sitting in traffic. When I began to move, it went away. Over the following weeks it became more persistent. It got to a point, while I was on the highway (70+ MPH), the same warning came up on the dash and the car automatically shifted into 7th gear, skipping all lower gears (even & odd). Even when I got off the highway (in manual mode), at 20 mph, it would automatically shift up to 7th gear.

During the diagnostic process we never determined root cause. After my first code, I changed the DCT Oil, Filters, Pan etc., the warnings went away for a month (maybe two) but came back rearing it's ugly head. Rather than going down a rabbit hole, I found a used DCT online and swapped that one in. I think there's three possibilities (in my scenario):

- Clutches are worn and need to be replaced
- Mechatronics unit is faulty
- DCT Thermostat is bad

You may be experiencing something different, especially if there are no physical symptoms.

[Helmsman]

Originally Posted by noremaC

Any physical symptoms when driving with the 5A53 code? Clutch slippage?

I'll share my experience from last fall:

I had this code pop up (5A53 = Phase Red, DCT Oil Temp >160 C) last year and ended up putting in a new (used) DCT. There is also a 5A54 code = Phase Black, DCT Oil Temp > 170 C. Not to scare you here just sharing my experience.

I got first the Transmission Overheating (5A53) warning when sitting in traffic. When I began to move, it went away. Over the following weeks it became more persistent. It got to a point, while I was on the highway (70+ MPH), the same warning came up on the dash and the car automatically shifted into 7th gear, skipping all lower gears (even & odd). Even when I got off the highway (in manual mode), at 20 mph, it would automatically shift up to 7th gear.

During the diagnostic process we never determined root cause. After my first code, I changed the DCT Oil, Filters, Pan etc., the warnings went away for a month (maybe two) but came back rearing it's ugly head. Rather than going down a rabbit hole, I found a used DCT online and swapped that one in. I think there's three possibilities (in my scenario):

- Clutches are worn and need to be replaced
- Mechatronics unit is faulty
- DCT Thermostat is bad

You may be experiencing something different, especially if there are no physical symptoms.

Cheers mate. I mainly got it in stop/go and even more so when the car already been driven shortly prior. This leads me to believe the oil is warm, no air cooling in traffic, and no coolant cooling (95C at least does something with 160C oil). I did get the code once or twice during high way as well. Yellow dash (rather then red), no limp mode really but the DCT start to act up.

The box only has 3k miles on it and this car has been living a very gentle live since, so really hard for me to believe clutches are worn. I will take it to an indy shop next week, they plan to replace the thermostat after BMW dealer input. Reason I'm looking for experience reg the aux pump is that if so I'd like that replaced while I'm at it. Sure could be done anyhow but as the code can stay away for months its tricky to understand what action result in what.

Where did you learn about the oil temperatures?

Cheers

[drwankel]

Be sure to follow up with the resolution.

[Helmsman]

Quick interim update: Finally replaced the aux water pump the other day (with regards to DCT over heated). So far...maybe makes a difference. Like to believe the heat from the DCT oil cooler is kept lower. Will drive for a bit and report back.

[Redd]

What is the part # for the aux water pump pls? I don't believe I've ever changed mine.

[Helmsman]

Originally Posted by Redd

What is the part # for the aux water pump pls? I don't believe I've ever changed mine.

Hey Eric,
BMW PN 64118369806. Why, do you get the A61D1 code?

Cheers
Nik

Ps. Sent my Arma back....

[Redd]

Originally Posted by Helmsman

Hey Eric,
BMW PN 64118369806. Why, do you get the A61D1 code?

Cheers
Nik

Ps. Sent my Arma back....

No code but I like to do preventive maintenance.

So what are u replacing the Arma with?

[Helmsman]

Originally Posted by Redd

No code but I like to do preventive maintenance.

So what are u replacing the Arma with?

Know what you mean but no need to swap that pump prior the code mate.

Back to stock intake. Fitment of the Arma set I got was simply too bad, need to be able to close the bonnet...

[StripclubDJ]

I have luck changing the temp/ clutch speed sensors when I'm doing clutches

Also, I remove a lot of baskets and find the nose cone that sends pressure through the basket, the bolts are backed out causing a loss of basket pressure , leading to clutch slipping , thus getting " overheat"



Hopefully any of this helps

[Helmsman]

Originally Posted by StripclubDJ

I have luck changing the temp/ clutch speed sensors when I'm doing clutches

Also, I remove a lot of baskets and find the nose cone that sends pressure through the basket, the bolts are backed out causing a loss of basket pressure , leading to clutch slipping , thus getting " overheat"



Hopefully any of this helps

Thanks mate, interesting.

Could you add a little around the driving style i.e. casual, lot of tracking etc. I know nothing about the inside of the box but seems strange that bolts are coming lose?
Also, under what circumstances did you get the over heat code?

[StripclubDJ]

Originally Posted by Helmsman

Thanks mate, interesting.

Could you add a little around the driving style i.e. casual, lot of tracking etc. I know nothing about the inside of the box but seems strange that bolts are coming lose?
Also, under what circumstances did you get the over heat code?

The car in that picture was a 1000% never tracked never modded daily driver

I seen the same thing from a car with 350 track
Days to a car that's never seen redline

Also they'd no pattern or correlation to when the the overheat warning pops up

[tdott]

Originally Posted by StripclubDJ

I have luck changing the temp/ clutch speed sensors when I'm doing clutches

Also, I remove a lot of baskets and find the nose cone that sends pressure through the basket, the bolts are backed out causing a loss of basket pressure , leading to clutch slipping , thus getting " overheat"


Hopefully any of this helps

Any special tools or procedure needed to remove the baskets and check those bolts? Have a spare trans I may open up to check.

[amrazM]

Originally Posted by tdott

Any special tools or procedure needed to remove the baskets and check those bolts? Have a spare trans I may open up to check.

Ssp sells the tool to remove the front cover and the tool to take out the basket. You need something to hold the gearbox more importantly.

[jp1984]

Good luck guys, hate to see these codes, it gives me nightmares. I hope the solution is the quickest easiest cheapest thing to fix possible. But, ya know...

[Helmsman]

Thread updated in first post.

[dtla1]

Originally Posted by StripclubDJ

I have luck changing the temp/ clutch speed sensors when I'm doing clutches

Also, I remove a lot of baskets and find the nose cone that sends pressure through the basket, the bolts are backed out causing a loss of basket pressure , leading to clutch slipping , thus getting " overheat"



Hopefully any of this helps

Hey, where/what shop are you located at (Can send you a message instead if you prefer).

I've had the DCT overheat issue one and off for maybe 6 years now. Replaced clutches at one point along with filters and new fluid, had fluid levels checked, had software resets etc done.

The last time I actually spent time/money on it, the shop I took to were able to read a sensor short, so I think I agree with you that it's a sensor issue (at least in my case). The light will come on and off very quickly, like 2 seconds sometimes, sometimes, a little long, but then off again. The trans will hold the RPM high before shifting I guess to protect itself. The few times it's show the red warning the trans will just not engage at all until I have the car rev'd to about 5-6K and then finally engage.

I want to get this fix, but considering I've already spent so much time and money with other stuff that didn't fix the issue I'm just hesistant to even try getting it fixed at this point. When the temp warnings come up though the car is a nightmare to drive and I strongly consider dumping it.

Anyways, it sounds like you/your shop has a lot of experience with these trans and maybe I can finally get it fixed soon.

[StripclubDJ]

Originally Posted by dtla1

Hey, where/what shop are you located at (Can send you a message instead if you prefer).

I've had the DCT overheat issue one and off for maybe 6 years now. Replaced clutches at one point along with filters and new fluid, had fluid levels checked, had software resets etc done.

The last time I actually spent time/money on it, the shop I took to were able to read a sensor short, so I think I agree with you that it's a sensor issue (at least in my case). The light will come on and off very quickly, like 2 seconds sometimes, sometimes, a little long, but then off again. The trans will hold the RPM high before shifting I guess to protect itself. The few times it's show the red warning the trans will just not engage at all until I have the car rev'd to about 5-6K and then finally engage.

I want to get this fix, but considering I've already spent so much time and money with other stuff that didn't fix the issue I'm just hesistant to even try getting it fixed at this point. When the temp warnings come up though the car is a nightmare to drive and I strongly consider dumping it.

Anyways, it sounds like you/your shop has a lot of experience with these trans and maybe I can finally get it fixed soon.

Dumping what?

[dtla1]

Originally Posted by StripclubDJ

Dumping what?

Dump the car, it's a frustrating to drive and sometimes unsafe with a transmission that has a mind of its. If it's just on the orange warning it feel like someone learning to drive with a manual, riding the clutch way too long.

[dgbattman]

I’m in LA and went down the path of oil and filter change, readapt, csf dct cooler, addition of a fan, etc.

Heat makes it worse, and it never happens when the transmission is below say 75deg C (still heating up)…it especially likes to happen on first warmup or subsequent drive after resting.

I would LOVE to replace that combination sensor if that’s the culprit, but also frightened to spend more on this nightmare transmission

2018 M2

[StripclubDJ]

Originally Posted by dtla1

Dump the car, it's a frustrating to drive and sometimes unsafe with a transmission that has a mind of its. If it's just on the orange warning it feel like someone learning to drive with a manual, riding the clutch way too long.

# I rebuild these transmissions and it's stupid simple to fix
# 2 a used trans is 1300ish $


Dump the car ? Lol

[MajorBob]

HI guys, I don’t mean to hijack the thread but you seem skilled at diagnosing and working on the DCTs and I may be dropping mine for the 3rd time . This time to replace the combination temp/ clutch speed sensors. Getting codes 5A58, 5A76 and 5A73 and this seems like the most likely cause. Curious if you agree or if there is something else I should check first? Also… Does anyone have the Clutch removal tool they would rent out? Happy to pay a reasonable amount and return when the job is done.
Thanks!