HELP! - Mechatronics Issues Mechanic Can't get head around

**JRG2** · 04-10-2015, 11:28 AM

Hi All

Firstly thank you for taking the time to read this. I am down to my wits end on what to do and some friendly advise would be very welcome.

My tale is long, but I will keep it brief.

I have a great mechanic, but even he is stumped. He has done the right thing by My car and I but I need other ideas now as we aren't getting anywhere.

I have a 2010 118 TSI Golf Wagon. Basically, 4 months ago the timing chain went slack and destroyed my engine. Before this the car ran perfectly in every way. It was a delight to drive and didn't have a single issue. So We put a second hand engine in. The engine was fine, but the transmission was not. Basically it bunny hopped and clunked and was not in a good way. It also got stuck in 3rd and 6th gear and wouldnt change up or down (automatically) This I thought was very weird as the transmission previously was perfect. Anyway, it went to VW to get diagnosed and they said it needed new clutches. So it got them. The problem remained. There was nuthing wrong with the old clutches so they went back in.

IN desperation my mechanic got hold of a second hand megatronics unit and put this is. It fixed most of the issues. The car was 'ok' to drive. Not as a good as it was. Still clunky in 1st and other gears at time but drivable. I just accepted this and got on with things.

Anyway 2 or 3 weeks ago the megatronics unit died. The car wouldn't start any more. Fault my diagnosed by plugging lumes from old megatronics in (and she started) where as the existing didn't. A BRAND NEW Megatronics unit was purchased and installed.

Now, the problem with the original megatronics and BRAND NEW are identical. And the fault is again the change the clutches.

Of course I am not keen to spend 2k on the clutches when they have been done before to no fix. How can the 2 units have the same fault, and clutches were done with the previous to no result.

To me it feels like a electronics fault of some sort rather than a mechanical fault. And I believe the original megatronics was never faulty.

Any ideas on what could be causing this. How does a new engine have any effect on the gearbox unit?

Thanks

**Umai Naa!!** · 04-10-2015, 12:00 PM

Never come across any non-starting issues relating to the Mechatronics unit, but I'd never rule it out.

I wonder what gear it thinks it's in when you're trying to start the car.

**JRG2** · 04-10-2015, 02:10 PM

It was throwing a Selector Error - The can must be in P/N to start (can't remember exact quote). New Unit has fixed that issue though. So unfortunately it was the Megatronics. Just the new megatronics unit does not work (just like the original).

How could a new engine change the way the megatronics unit operates to cause an issue?

Originally Posted by Umai Naa!!

Never come across any non-starting issues relating to the Mechatronics unit, but I'd never rule it out.

I wonder what gear it thinks it's in when you're trying to start the car.

**Umai Naa!!** · 04-10-2015, 02:48 PM

Was it coded to the car, and basic setting performed?

**JRG2** · 05-10-2015, 12:35 PM

Originally Posted by Umai Naa!!

Was it coded to the car, and basic setting performed?

I am told it was.

**Bug_racer** · 05-10-2015, 06:52 PM

Any faults come up ?

**grtuned** · 05-10-2015, 07:25 PM

A 7 speed dsg would cause no start if it was faulty I've seen it before.
You need to start from the start. Best advise would be to check all harness connections after the engine was changed funny how you started having issues since new engine replaced?

**Snail Style** · 06-10-2015, 05:34 AM

So you put a second hand motor in and kept your original gearbox in? Or is it a second hand box also?

**JRG2** · 06-10-2015, 02:17 PM

Originally Posted by Snail Style

So you put a second hand motor in and kept your original gearbox in? Or is it a second hand box also?

There is second hand motor, original Box. But the box was playing up with the new Motor, which meant a new megatronics unit. New Megatronics is playing up. Which makes me think there is not a megatronics issue, it is something else.

**Snail Style** · 06-10-2015, 02:55 PM

Can you give me the vin of the original vehicle and the donor vehicle?

Most likely is you have the incorrect flywheel fitted. At a certain year break they changed the clutch design. Incorrect flywheel throws the adjustment out.

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