DSG7 MECHATRONICS OVERHAULING
Due to the high pressures encountered within the unit, both and ECU Testing advise against DIY dismantling the Mechatronics as it can cause permanent damage, as well as severe safety risks. We’re including this section on overhauling purely for academic interest to highlight the parts within the unit. These are NOT instructions for how to do the task at home.
37 Viewing the Mechatronics face that enters the gearbox, several small screws retain a protective metal cover, beneath which is the main ECU. Naturally, any penetration of the gearbox oil will render the ECU useless.
38 This delicate PCB is clearly unrepairable and replacement is the only solution. Accessing the ECU at home might ruin any chance specialists may have to extract data from it, so resist any curiosity.
39 The entire PCB assembly, with sensors, can be unbolted and lifted out. It is replaced as a single unit. On the reverse side, the board has clearly overheated, as is evident from the damaged plastic.
40 ECU Testing can interrogate an ECU after it has been removed, including reading and saving any vehicle-specific data, which can be uploaded onto a replacement ECU.
41 On the other side of the Mechatronics is the outer sump cover. Although all fluid is drained beforehand, ECU Testing warns that extremely high pressures may lurk behind the cover; you should NOT remove it.
42 Beneath the cover, pictured from left-to-right is the hydraulic accumulator, the hydraulic pump and the pump motor. All of these parts are immersed in the DSG7 Mechatronics unit's oil supply that is separate to that of the gearbox (unlike the DSG6).
43 The accumulator stores around 60bar (870psi) of pressurised lubricant and it can fail. ECU Testing reports that these have to be disposed of by a specialist and the company has a number of safety procedures in place for their safe removal. 44 The pump and electric motor can be removed from their mountings and then separated and renewed, where necessary.
45 Just like conventional slave cylinder pistons, the clutch actuators can be removed and their seals replaced. Their liners are held in by a circlip, meaning that they can also be extracted.
46 The main hydraulic block can also be removed, owing to the sandwich-type construction of the Mechatronics unit. Visible here are four of the solenoids as the unit is being withdrawn from the aluminium body.
47 This leaves the main casing. Pictured inside is the main internal gasket and filter. On the other side are the gear shift actuators, which can also be removed and then overhauled, where necessary.
48 Despite not being available to the general public, all parts are obtainable by specialists, enabling them to completely remanufacture a DSG7 Mechatronics unit. The main difference between remanufactured and new units is that your car’s software can be uploaded to the original unit, saving you time and money.