Transmission problems

[ensignia]

Hello all, been having a few problems with the MC Shift transmission on my 2010 GTS and just know that someone on here will be able to diagnose exactly what the issue is.

So, I was doing some spirited driving in MC Shift mode, and when I went to change from 3rd to 4th at around 7k rpm the message 'gear unavailable' flashed up and it went into neutral. It's done this a handful of times in my ownership but usually always goes back into gear and I can carry on with my journey slightly less enthusiastically.

This time it was stuck in N for around 30 seconds, but after a few goes managed to get it into gear and limped off into a residential area to investigate. I let it cool down and tried again. There was no R gear (gear unavailable), and the gearbox kept wanting to go into N but managed to get it home by limiting it to gears 1-3.

I know the F1 fluid was low as the message had popped up on the screen, so took it to a garage and got them to refill it and bleed the system, hoping that would fix it. No dice.

- Still no R gear, and no idea whether the forward gears were working as expected.
- Holding down the R button flashes up the message Transmission Failure or something along those lines.
- At this point the car started and could go from N > 1 but not N > R.
- I can hear the actuator(?) working and clicking two or three times as if it's trying to engage R.

I have access to one of those Autel diagnostic systems, so tried to see if I could find some answers. It seemed to cycle through all the gears except R.

A quick scan of the F1 Gearbox revealed this:

There were a few different menu items within the F1 gearbox section, which I went through and made a note of the values:

 

[ensignia]

The car will no longer start at all and just says Gear Unavailable on start now, so guess I must have changed a value somewhere

Sorry for the long post, and appreciate any advice people may have to offer

 

[cheshiremaserati]

Looks like you need to have it trailered to a specialist. You could be shooting in the dark a long time at considerable expense.

It doesn't sound like a DIY fix.

Let us know what the specialist says and how it gets fixed.

 

[CatmanV2]

Hate to start with the obvious but the P1747 would upset the car a lot I suspect.

C

 

[spkennyuk]

Code P1747 indicates a reverse leaver / switch fault.

The low transmission fluid level means your loosing fluid somewhere.

If the autel allows you to access the live data from the F1 pump then have a look at the pressure readings and see if the pressure is dropping off too quickly.

It should hold enough pressure for several gear changes before the pump needs to fire again.

First things first though. Disconnect the battery for 15 mins or so and then reconnect and see if anything changes.

Really needs a proper diagnostic but if we can at least get you moving again to drive it there then it will make life easier.

The other error codes indicate there may be a wiring issue on the canbus or faulty ecu.

I would also make sure the battery is fully charged and in good condition.

P0721 i think is saying the the gearbox tcu is not getting a signal for the engine RPMs which again could be indicating a wiring fault or ecu failure or fault.

 

[Zep]

As the others have said, it’s probably going to have to go to a specialist.

It seems like, before your second post anyway, that you have a bit of air in the valve block which is preventing the reverse solenoid from driving the actuator, maybe sucked in when the fluid was low.

I assume, when you said you could hear all the gears engaging, you have done a gearbox relearn with a fault and now it’s in a bad mood with you. Perhaps the bleeding wasn’t entirely successful.

Try battery off like Stu said, make sure all your plugs are seated (the TCU is behind the cover on the right of the boot) and then think about a tow.

 

[Cdn17Sport6MT]

Other than the bleeding of the clutch release bearing (throw-out bearing) - nearest as I can tell, bleeding of the F1 system is only possible by disconnecting the parking brake cables, dropping the exhaust, and unbolting the F1 actuator from the side of the transaxle case (with all hoses, electrical still attached)... This is to cater for access to the three slotted head screws that must be backed-off their respective seats to allow actuator bleeding to be done, using an SD, Leonardo, Launch X431 Pro, etc. to orchestrate the bleeding operation.

Has this been done? It is not a really trivial exercise...

 

[cheshiremaserati]

None of that is DIY!

Just have it trailered and let a specialist sort it.

 

[conaero]

It’s impossible to tell without seeing it but here are some of my observations:

PIS 3.8mm should be 4.19

No signal from wheel sensors. If the gearbox cannot understand what each wheel is doing it will go into meltdown. There is also a speed sensor on top of the box.

What is the mileage of your current clutch. They start playing up late 30k’s, limp on to early 40k’s then fail or slip late 40k’s

if you can on your tool do a hydraulic pressure leak down test (you can do it audibly by timing pump prime times). Engine running, in neutral start timer. Anything over 5 mins is good, 6-7 excellent.

If it keeps priming less the hydraulic block/solenoids are leaking internally.

Next flip between 1st and Neutral and listen for the pump. You should get 3-4 shifts between priming

Finally time you pump priming duration. Should be 3-4 seconds, with the occasional longer one. If they are all 10 secs again you have a pressure leak.

If the pump sounds healthy and strong in its wurring, change the F1 relay. It’s cheap and quick.

Report back your findings.

 

[ensignia]

Thanks for the replies all.

It's worth noting the battery, although only a couple of months old, went flat when the garage was carrying out the repair and needed a booster to get it started again.

My initial thought was that the clutch needed replacing as it's on around 35k miles now I believe. The garage reckon it could be some sort of issue with the solenoid to enable R.

Just need to get it back to its previous state where it at least started and had forward gears, then I can take it to a specialist (SMDG are nearish).

Current state is brake pedal is hard to press and turning the key does nothing with gear unavailable showing on the screen.

 

[Zep]

Oh dear, I don’t like the sound of that jump start!

 

[conaero]

Could be the brake pedal switch, this needs depressing to select R and 1st

 

[ensignia]

Oh dear, I don’t like the sound of that jump start!

Why, pray tell? I know jump starts aren't recommended for these cars but seems like only a hardcore few adhere to this rule.

Also, the car had been sitting for over a week while they got around to it.

Could be the brake pedal switch, this needs depressing to select R and 1st

The brake lights come on when brake is pressed. This would probably rule that out, no?

 

[CatmanV2]

Why, pray tell? I know jump starts aren't recommended for these cars but seems like only a hardcore few adhere to this rule.

Also, the car had been sitting for over a week while they got around to it.



The brake lights come on when brake is pressed. This would probably rule that out, no?

It's a two way switch, as a safety feature. Both sides need to work so in short, not necessarily

C

 

[Zep]

Why, pray tell? I know jump starts aren't recommended for these cars but seems like only a hardcore few adhere to this rule.

Because when you started you could get some gears, and now you have canbus errors and no starts. It’s not a slam dunk, but there are lots of things going on at once here.

 

[ensignia]

Couldn't get to the bottom of it, so am having to have it trailered. The nearest place I can think of is SMDG in Horsham.

Anyone know of any specialists nearer to Horley/Crawley?

 

[Sam McGoo]

Couldn't get to the bottom of it, so am having to have it trailered. The nearest place I can think of is SMDG in Horsham.

Anyone know of any specialists nearer to Horley/Crawley?

Surely you'd go Sportsitalia, or AV from there.

 

[JMS]

Sounds like my worst nightmare (had my MC shift 4 months and hate the random dashboard warnings)

Good luck getting it sorted and please post updates.

 

[cheshiremaserati]

Couldn't get to the bottom of it, so am having to have it trailered. The nearest place I can think of is SMDG in Horsham.

Anyone know of any specialists nearer to Horley/Crawley?

Best decision. These cars are complex and tinkering around still leads to the same end point - a specialist with the tools and know-how.

It will be sorted. I have Autoshield near me and Marios and his team really know these cars inside out. I just phone and let Autoshield look into anything that worries me.

Good luck and let us know what it was and how it was fixed.

 

[ensignia]

Surely you'd go Sportsitalia, or AV from there.

Well, one is 15 miles away and the two you've suggested many more than 15, so...

Sounds like my worst nightmare (had my MC shift 4 months and hate the random dashboard warnings)

Good luck getting it sorted and please post updates.

I think it's just air in the F1 system somewhere, it was just reverse missing until I started to tinker around with it.

The bigger issue is what went wrong with the clutch initially. I calculated clutch wear to be at 53% using the closed clutch position formula, so potentially not a new clutch as I thought...