s8 gearbox in safe mode

[audis8tui]

Good evening gents. after putting in a replacement engine that came with a gearbox I decided to use the gearbox as the engine was low mileage and in good condition once checked inside. The engine and box are fitted and the engine running lovely but the gearbox has no drive to the wheels at all.
I have checked the fluid while running and going through the gears and its good. While underneath with my wife running through the gears I can hear the mechanism working and the revs change on the engine.
I have noticed that the dashboard gear indicator doesn't highlight which gear is selected and the mileometer is reading SAFE. I have plugged in the Vagcom and it says solenoid lock. Has any body got any ideas? Regards

[Delboy]

Oh man that's unfortunate.

The safe message is normally related to keys and I have had it after a battery disconnect but it sorts itself out.

As for the gearbox solenoid can you copy and past a fresh scan of the car after trying to clear out faults first.

Did you also check to see if gearboxes matched part numbers as there is options depending on years.

If that all checks out the only short cut you could possibly try would be the mechatronic unit from inside the gearbox.

But personally if I were you and I would go straight at replacing the box with your known unit that you serviced.

[audis8tui]

Originally Posted by Delboy

Oh man that's unfortunate.

The safe message is normally related to keys and I have had it after a battery disconnect but it sorts itself out.

As for the gearbox solenoid can you copy and past a fresh scan of the car after trying to clear out faults first.

Did you also check to see if gearboxes matched part numbers as there is options depending on years.

If that all checks out the only short cut you could possibly try would be the mechatronic unit from inside the gearbox.

But personally if I were you and I would go straight at replacing the box with your known unit that you serviced.

Hi, I have had the battery off 3 times with the key left in the ignition so the suspension stays correct but as the original engine and gearbox have been out 3 times I wonder if I have screwed up the electrical system.
I didn't check the part numbers but it was the same year car it came from.

When you say mechatronic do you mean exchange the electrics in the gearbox for my old unit, this would be preferable to removing the whole lot again.

My Vagcom justs says locked when I go to transmission which wont clear.

I did service this box before fitting it thinking as the engine is low mileage and well looked after the gearbox would be the same, I could kick myself

[Delboy]

Yeah if you remove the oil pan you will see the brains of the gearbox that controls it with all the solenoids in it, it can be removed as a complete unit and swapped over but I couldn't say if it's compatible or will cure your issue.

im guessing the engine and box have to come out again to separate?

[audis8tui]

Originally Posted by Delboy

Yeah if you remove the oil pan you will see the brains of the gearbox that controls it with all the solenoids in it, it can be removed as a complete unit and swapped over but I couldn't say if it's compatible or will cure your issue.

im guessing the engine and box have to come out again to separate?

I will try the brains first as that's just the exhaust off and drop the pan. the gearbox out is a everything out job and I am about done taking this lump out for the fourth time

[Mechcanico Lee]

Yes does sound like mechantronic coding , has it gone into safe due to component protection miss match .
If gearbox is same part numbers you should be able just to swap the guts over like already said , bet you had enough of taking that engine unit in and out !!

Keep at it though your nearly there 👍👍

[audis8tui]

Well the gearbox brain is out and what a lump it is. 5 hours and what a pain, the down pipe bolts are near on impossible to get to when fitted to the car but need to come off along with the subframe cross member to allow clearance for the pan to drop.

The gearbox oil is one of the worst smelling and skin irritant oil I have ever worked with and when under the car on axle stands even after draining it still manages to get everywhere.
Overalls in the wash ready for the refit tomorrow.

[audis8tui]

Well after a 2 week messing about with the engine then replacing it and keeping the attached gearbox and then swapping the gearbox electronics it all works a treat.
It sounds and goes as it should with no leaks and no warnings. Vagcom is happy as am I, just need to fuel up and go for a ride then get the aircon recharged and fit the front bumper.
Hopefully now I have time I can repay the good feedback and advice from you guys and help others as I now know so much more about this car. Regards

[Architex_mA8tey]

Congratulations on getting there! must be very satisfying to see it all behaving itself

[Lee S]

Well done man... Enjoy !! I think I'd put the front bumper on first before going for a ride though..