[boatman]

Warning long post, but wanted to get to the bottom of what might be the cause of this problem and if anyone else had experienced something similar in their 600LTs.

This is a new car, heavily MSO specced, ordered from factory. I've never had this problem with my 570S either on the road or track before. Also I'm a long term track enthusiast so I know what I'm doing with the car, I'm not shifting randomly and having the car reject shifts. I've driven some cars at similar caliber and never experienced something like this; my car is ordered new, I didn't expect there to be issues like this at all.


Problem: When upshifting in more spirited drives (Manual, Sport Mode), the car doesn't shift up to the next gear and instead downshifts (because of this and the speed it happens at, it drives the RPM all the way up to redline).

• Happens most often in gear 3 around 6k RPM. Sometimes it flashes to 4 then drop straight down to 2, revving the RPMs like crazy. Sometimes it doesn't shift up and stays in 3. Sometimes it doesn't shift up and downshifts to 2. (Refer Videos)
• Happens most often as you are just starting to do spirited drives after warming everything up, but I've had it happen later on in the drive as well just less often.
• So far I only had it happen in Manual, Sport Mode. I didn't have the chance to fully test the problem in Manual, Track Mode, but in the short time I did I haven't had the problem happen.
• Happened twice in First Gear also around 6k RPM, car doesn't shift up as supposed to and instead stays in First Gear and the revs hang. I wasn't able to replicate the First Gear problem when I am recording the test drives, also due to limited road conditions for launching, but the problem did happen twice without launch control, just normal acceleration and shifting at around 6k.
• Happens completely at random during spirited driving. Best bet is 3rd shifting to 4th at 6k. On average happens 3-5 times in a 1hr drive. (Note: this is just spirited driving after car is warm, not pushing hard on the car, shifting at redline, etc.)
• After the problem happens, it rejects upshift commands for about a sec, the best way I found when the problem occurs is to not touch anything and just brake to let the revs drop down and slow the car until it is normal again.

I've noticed the problem after slowly finishing break in and starting to do some spirited drives. The uncertainty is I don't know when it will happen, or if it will happen in other modes, other RPMs, under what conditions, and that leaves me worried while driving. I can't 100% replicate the problem but I know it is definitely there.


TLDR: can refer to videos directly.
Video 1
Video 2

In the videos, I've successfully replicated Gear 3 attempts. During testing I ensured my foot was on the accelerator with no sudden lift off (though I tested even if I lifted off the car shifted normally), and because we have rocker shift paddles, it's impossible for me to pull downshift while upshifting.

Also this is happening during really pretty low intensity spirited driving for this car's capabilities, I am not really pushing it as I'm not on a track and also I prefer to be gentle with my cars. The problems occurred at least once every time I was driving the car, the videos are recorded in the same afternoon during a 1 1/2 hour period of spirited driving.

• Video 1: You can see after I pulled the upshift paddle, (if you play it slowly) it flashed to 4th gear then dropped straight down into 2nd, causing it to rev crazy high.
• Video 2: In 1st attempt, it didn't upshift when I pulled the paddle and instead stayed in the same gear. In 2nd attempt, it didn't shift up at all and instead downshifted also sending RPMs high. 3rd attempt was normal. 4th attempt, if you play slowly, the car flashed up 4th gear and didn't stay, went back to 3rd then down straight to 2nd.

Obviously I don't have the space to test through every rpm band, I just found that Gear 3 shifting up at around 6k is the easiest to make the problem appear. I don't know if it will happen at other RPMs or other gears. So far I had the issue in 1st and 3rd gear.


Please chime in if anyone know what might be the cause of this or ran into similar issues. I've contacted my dealer but haven't heard back yet. I suspect it is software related but last time I was in the shop my dealer told me it was updated to latest software.

 

[shack]

I have the EAXCT same issue. Car is new and I was running it in. Dealer sent my video to McLaren and they came back recommending clearing the system of data so the car can "re-learn". It still happens and as you say its a bit erratic.

Both techs at my dealer tested the car and could not get it to replicate the issue. I am aware that the system uses accelerator position as one of its inputs and i have not fully tested whether this has an affect i.e. I need to accelerate harder to avoid the issue. I do tend to "lift off" the accelerator a bit so am still not 100% sure its not driver issue.

Please keep me informed in your progress and I will do the same

Also if the techs at your dealer want to chat with my techs - please PM me. Might be useful for both of us.

 

[boatman]

For sure. I did test this pretty extensively. I used to race with manual cars but i tracked with my 570s before owning the 600lt, ive consciously had my feet down while testing and the problem occurs. I thought it could be lift off and i tried lifting off in several tries and the car shifted normally, so i don’t think it is directly related to lifting off throttle.

i’ve also suspected it might be the force you pull on the paddles, maybe you have to pull fully with force for the system to register a shift command or else it wouldn’t be sure. In the tries i consciously pulled harder the problem didnt occur once, but even on lighter pulls the paddles do click, and it shifts gears other than 3rd fine. However paddle force havent been confirmed to cause the problem.

I don’t like always pushing the car hard and maybe thats what it is? I’m waiting to hear back from Mclaren on this but its apparently not just one person with the issue and it should be brought to attention.

 

[dvandentop]

looks like you are flicking up and down paddles at same time In video and it chose to downshift vs upshift

looks like 2nd shift looks like paddles move differently for some reason

 

[LRHunter]

I’ve never had that issue and I also have a heavily spec‘d MSO 600LT as well.

I do have an idea of what might being going on from watching your first video.

In your first video it looks to me like you are flicking the upshift and the paddle is bouncing hard enough to slap back the other way and causing it to activate the downshift. If you slow the video down enough, I’m betting it‘s actually bouncing hard enough that it’s slapping twice on the downshift direction. That would perfectly explain the split second 4th, then it’s double tapping the downshift and dropping it to 2nd.

I do not flick my shifts, but do a more deliberate (but not slow) pull and haven’t had that problem. Try changing the way you pull the paddle and see if that fixes it. It could also be that the mechanism used to dampen the paddle is bad, which is allowing it to bounce, so might not even be software at all, but the actual hardware on the paddle shifter.

 

[LRHunter]

Another thought, there are 4 bolts that hold the paddle assembly to the steering wheel, if those are loose, then the paddle assembly might be a little loose as well, allowing the paddles to bounce/rattle when you flick shifts. I would have the dealer check those bolts and that mechanism.

Do your paddle shifters feel a little loose, or are they nice and tight?

 

[shack]

Btw did u try replicate it in auto mode ?

 

[Gary(SF)]

looks like you are flicking up and down paddles at same time In video and it chose to downshift vs upshift

Since the paddle is a one-piece center-pivot design how would that even be possible?

 

[LRHunter]

Since the paddle is a one-piece center-pivot design how would that even be possible?

It’s not, but see my post above.

He’s flicking it hard enough that it’s bouncing back the other way and activating a down shift.

 

[Gary(SF)]

Ah, ok, I can see that as possible.

 

[boatman]

Btw did u try replicate it in auto mode ?

I havent ran into issues in auto mode yet.
Do you also flick your paddles or do a full pull?

 

[boatman]

It’s not, but see my post above.

He’s flicking it hard enough that it’s bouncing back the other way and activating a down shift.

I did see that might be a possibility of it swinging back. But it doesnt have enough force to click the opposite way i only hear one click as i shift up.

also ive been shifting like this all the time in my 570 with no issues. Maybe the paddle is way more sensitive in the 600? or like you said the paddle sensor might be bad, i’ll have the dealer check that while experimenting more.

 

[boatman]

Another thought, there are 4 bolts that hold the paddle assembly to the steering wheel, if those are loose, then the paddle assembly might be a little loose as well, allowing the paddles to bounce/rattle when you flick shifts. I would have the dealer check those bolts and that mechanism.

Do your paddle shifters feel a little loose, or are they nice and tight?

my paddles dont really wiggle when im moving but it might be loose as you said. Regardless i’ll have them check that mechanism. Thank you for your inputs!

 

[LRHunter]

I did see that might be a possibility of it swinging back. But it doesnt have enough force to click the opposite way i only hear one click as i shift up.

also ive been shifting like this all the time in my 570 with no issues. Maybe the paddle is way more sensitive in the 600? or like you said the paddle sensor might be bad, i’ll have the dealer check that while experimenting more.

Just watching your video it’s what it really looks like to me. Keep a close eye on the downshift paddle in the video on all the shifts. On the shifts where it does it, it sure looks to me like I see a lot more vibration in the downshift paddle, which makes me think that’s causing it.

There are actually two buttons on the back of the steering wheel, one on each side. The paddle assembly rocks back and forth on a center pivot and presses against those buttons. It could even be a weak spring in the downshift button that’s allowing it to be depressed too easily when you flick the paddle just right so that it bounces back with enough force.

There’s a number of things in that mechanism which could be causing it, but from the videos it sure seems to me like it’s how you are shifting. Not that I think the way you are doing it is wrong. I think it should be able to handle shifting the way you do it, but I think it’s a mechanical issue vs. software.

Good luck and report back what you find. I’ll take my LT out this weekend and see if I can replicate it shifting the way you are doing it.

 

[boatman]

Just watching your video it’s what it really looks like to me. Keep a close eye on the downshift paddle in the video on all the shifts. On the shifts where it does it, it sure looks to me like I see a lot more vibration in the downshift paddle, which makes me think that’s causing it.

There are actually two buttons on the back of the steering wheel, one on each side. The paddle assembly rocks back and forth on a center pivot and presses against those buttons. It could even be a weak spring in the downshift button that’s allowing it to be depressed too easily when you flick the paddle just right so that it bounces back with enough force.

There’s a number of things in that mechanism which could be causing it, but from the videos it sure seems to me like it’s how you are shifting. Not that I think the way you are doing it is wrong. I think it should be able to handle shifting the way you do it, but I think it’s a mechanical issue vs. software.

Good luck and report back what you find. I’ll take my LT out this weekend and see if I can replicate it shifting the way you are doing it.

Thanks for all these info. I do really appreciate it. I’ll pay attention to those parts and see what the dealer can find.

i’ll also take it out next week and try to shift differently to see if that gets rid of the issue. I used to drive alot column mounted so the flick method might unconsciously became a habit.

 

[shack]

I havent ran into issues in auto mode yet.
Do you also flick your paddles or do a full pull?

To be honest I think I am a "flicker" but will try both next time.

My tech did mention this possibility of the spring "snapping" back too quickly and causing a downshift but it was only a mention.

I know it might sound silly and I will do the same but if you used your downshift paddle (left hand one) to upshift (push it backwards) and see if that still causes the issue. It would isolate whether its hardware or software.

Due to COVID issues here its difficult to use my car but I will see what I can do

 

[JW1]

Just a thought. Why don't you try taking another 600LT out for a test drive when you are at the dealer to see if it occurs on a different car. If it's a driving habit, then it should be reproducable in the test drive cars as well.

 

[8ULL]

I doubt that it’s your driving. The way the gear number flickers on screen when it screws up looks like a fault with the car.
The paddles are quite stiff so doubt it would be paddle bounce unless it was loose. Does it happen when you just use left paddle for upshift and downshift?
Looks like a dealer visit to rectify.

 

[Elgato]

I think its you flicking the shift paddle, I did the same thing in my 570s in the beginning. Its shifts up then down instant. Coming from an R35 GT-R and its a lot different paddle shifters

 

[boatman]

I doubt that it’s your driving. The way the gear number flickers on screen when it screws up looks like a fault with the car.
The paddles are quite stiff so doubt it would be paddle bounce unless it was loose. Does it happen when you just use left paddle for upshift and downshift?
Looks like a dealer visit to rectify.

no i tested the left paddle and it upshifts fine. also had no problem with downshift. It seems to be right paddle upshift (only in manual sport mode and around 6k) where the problem appears.