DSG, PRNDS issue,advice needed.

[zornyan]

Right, following on from my last thread, to keep it short

My DSG box (54 a3 2.0 tdi 140) was leaking dsg oil due to physical damage from previous owner letting the flywheel smash the bell housing apart

Box ran/drove absolutely fine, did several hundred miles in it (leak was approx 100ml over 500 miles) But obviously wanted it fixed

Sourced a replacement of the same code (GYN) that had no mechatronics, removed my box, removed mechatronics (carefully) and fitted into the new box, filled with new oil and filter.

Fitted back up, went to drive car, got to 30mph and car dropped out of gear and PRNDS flashes with no drive

Have following codes

inplausiable mechanical gear disengagement p2711 no commuction/signal

Implausianle mechanical gear disengagement p2711 no basic setting/adaption

So put car on recovery truck and took to a friend, plugged in vagcom, did adaption, brought car back to mine to carry out test drive. Same thing happened again with same codes.

I’ve since

Removed mechatronics again, no damage was present (to double check)

Swapped the input shaft speed sensor to one from my old box

Swapped oil pump to one from old box

No changes at all, completely out of ideas, this new gearbox has only 70k miles on it, so I’d be surprised if it’s the clutch packs? Feels really tight when I can use it, but always drops out of gear between 30-40ish irrelevant of what gear I’m in.

To add, I can floor it in first/second and there’s no clutch slip etc, picks up and pulls hard.

No idea where to go from here?

 

[SootySport]

Mechatroncs box is prone to water ingress on the older dsg cars. There are ECU repairers out there that will repair them and seal them properly. Google dsg ecu to find one.

 

[zornyan]

Mechatroncs box is prone to water ingress on the older dsg cars. There are ECU repairers out there that will repair them and seal them properly. Google dsg ecu to find one.

The issue is I’m not sure that it is the mechatronics, as stated in my post the mechatronics was fine, it’s merely been transferred to the new gearbox, there were no fault codes before this.

What I’m trying to figure out is what else on the gearbox itself can be causing the issue

 

[samuelh_888]

I was thinking mechatronics unit too - if the issue is now happening on a second box then get the mechatronics unit looked at.

 

[zornyan]

I was thinking mechatronics unit too - if the issue is now happening on a second box then get the mechatronics unit looked at.

Not sure if my OP isn’t clear?

First box/mechatronics =fine, no code, no issues

First box replaced because it had DSG fluid leak albeit very slow

New box didn’t have mechatronics

New box has my old Mechatronic that was all fine fitted

New box has fault code/PRNDS/limp mode

 

[samuelh_888]

Your OP was clear.

I was simply offering an alternative option which is what you asked for.

I’m not a DSG specialist so can’t help further. Do as @SootySport suggests and bet it booked with a specialist. Or search this forum, these is several recent threads.

 

[zornyan]

Your OP was clear.

I was simply offering an alternative option which is what you asked for.

I’m not a DSG specialist so can’t help further. Do as @SootySport suggests and bet it booked with a specialist. Or search this forum, these is several recent threads.

I have checked out the recent threads (not having a go mate) what I’m trying to ask for help is, is finding out if there’s any part of the physical box itself that could effect g502/501 sensors working/pick up, or if there’s any other part that can be tested using vagcom.

Not going to take it to a garage as they’re only going to plug it in vagcom and tell me to replace the clutches or mechatronics, which I already know are good and functional.

 

[leshkin]

Could be a few things, so we would just be guessing...

Have a read about the P2711 code: http://wiki.ross-tech.com/wiki/index.php/19143/P2711/010001

Possible Symptoms

• Malfunction Indicator Light (MIL) ON
• Transmission Malfunction
• Erratic Driving Behavior

Possible Causes

• Double Clutch worn/faulty
• Worn/Damaged gear shaft(s)
• Output Shaft Speed Sensor 1/2 (G501/G502) faulty
• Mechatronic Unit for Double Clutch Transmission (J743) faulty

Possible Solutions

• Check Output Shaft Speed Sensor 1/2 (G501/G502)
  • Check Measuring Value Blocks (MVB)
• Check/Replace Double Clutch
• Check/Replace Mechatronic Unit for Double Clutch Transmission (J743)

Given that you are having the issue in any gear, my money would be on the mechatronics module, especially if the speed sensor and clutch pack are fine - you could do well to get it checked by someone like ECUTesting (I used them when one of the solenoids packed-in - the price and service was great). While it may not look like it's damaged from visual inspection, the large number of fluid passages and solenoids themselves are well known to block/stop working correctly. A proper diagnostic of the module would at the very least confirm that the unit is functioning perfectly and if it's faulty, it can all be repaired/cleaned.