P17BF VW DSG Transmission Fault Cause



hey guys this is a zero a.m. DQ 200 mechatronics unit now for the seven-speed dry clutch DSG transverse gearbox and it had a p1 7bf all codes towards the pump play protection and we're just gonna basically have a look at the unit see where the issue lies some of you may know about this already but I just thought I'd share a video on this where the issue lies what we're planning on attempting just learn a bit more about these units basically now this unit that's been replaced I've decided to take it apart as we had a massive dent in the front cover which I'll grab just now and show so the front cover as you can see it's quite distorted and that's where we lost our pressure well that's what we had an external leak and why this unit was replaced so I decided I would remove the cover from the mechatronics just covering itself which is I'm did all these bolts but hold on once the unit was replaced because this was just gonna be done in the bin as you've seen in previous videos of mine I do like to take things apart and just see what the cause of failure is I know as we can see this is a threaded section here these are threads you can hear my fingernail just clicking along there is a section of thread missing here and that is what goes in there basically now this is quite a common issue with these gearbox mechatronics units so when they come with these pump play protection codes they basically this is the pump Mario here and they've they've blown they've burned the accumulator out and the reason they've blown out is B just because of the gun only assume is poor casting as it is looks like a cast finish looks like a narrow chocolate bar basically it's um it's just not strong enough for the pressure I think there's something like a car on what the pressure is that's in here but it's a your 20 or it could be 40 bar or something that's in that accumulate I can't remember the top my he'll have to look it up under and confirm but it's it's a great amount of pressure this is the accumulator as you can see that screws into there and that's what's black that blows out and that's what put some massive dent in the in the housing now as soon as that blows out and lose all of your pressure that was that was inside the accumulator so he just dumps all that pressure basically and then you get it all shoot out inside of the gearbox because an external Lake and if it doesn't blow that cover if it just because even when that cover's blown out the unit he's still kind of held in because you've got probably 50% of its threads still there so it pops out you know 10 mil or something saying and it just gets jammed in place so this pops over to one side the accumulate comes out but blows that cover I've seen them also where they don't blow the cover and you start seeing the oil coming out of this breather here so as you can imagine it if it's cracked just below here it's going to push this pressure that's coming out of here straight out of there and the pumps electric so the pumps going to run no matter what if if it's trying to build pressure so it's that's why you get the play protection codes because this thing's almost in hand probably in an overheat state and it's just protecting itself so it would almost be like as if it try to run itself with no fluid inside the inside the unit itself if there was no fluid in there you know not because of say this pressure loss but because there's empty he's just going to try and protect the pump instead of sorry the motor or the pumps that stop it burning out but yeah if there's a crack if it cracks forever alongside it may well do this is the first one I've taken apart I can see why and if there's is able to maintain a level of pressure it's going to leak out as the pump still trying to build it out the top so it's coming out of this this Bravin I actually made a video before where I just observed one that was blinking out of here you could just even see smoke coming out you see oil coming over into the ribs to the top of mechatronics unit and the car more driver has the same pee codes of pump play protection so yeah this unit is staffed base today so there is guys I've seen I believe they may be in there in Russia I'm not sure where they are maybe Eastern Europe or I'm really not sure where that the company is based but I believe you can buy some form of replacement that uses these bolts or something and maybe have to drill a hole to mount it and it basically uses a another accumulator and instead of you know having to replace this this whole aluminium section it uses a smaller thread so the accumulator body will be the same size but the thread will be slightly smaller and you just screw in a cup that goes in here with a smaller thread boss and you can then screw in this you know smaller diameter accumulator based low that goes in there and you repair repair the union it just uses these as its as its mounting points that might say I think you have to drill a hole or something it's something I'm interested in doing just is just for my own research and it's in if it is something is more of a effective or cost effective repair because the cars these are fitted in all the lower lower end vehicles now your polos your gulfs and a threes caddies etc you know they're all coming along the lines where they're coming up to ten years old now some of them and there they go into the scrap yard because they're are so expensive to to chuck one of these units in like we're in Australia these things are about three grand or something's put in one of in a car so I think it's something like that so it's um you know there might be need for say more cost-effective repair whether however it's whether it is cost-effective the labor involved I say I haven't done this yet this cover does come off easily I'm not sure if you can do this in the car with regards to the actual repair I would imagine you can get all the cover off in the car and probably the accumulator out but whether you can do the repair in the car and I don't know if you have to disassemble the unit say because this unit inside of here is separate to the actual aluminium casing so that's something else that we have taken into account but yeah this is something I'm definitely interested in doing so if anyone's interested I will buy the kit and do a repair on this unit and I'll see if I can install it on a currency test it

One Comment

  1. Carl Costello said:

    HI https://youtu.be/JBNtHqSCzsc

    June 30, 2019
    Reply

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