slickrick

I’m considering purchasing a 1st Gen. Macan Turbo and got a PPI done that popped up a fault code - P174B00. It reads “Main pressure valve in gear train half 1 - electrical fault”. The code status is Passive / Sporadic.

Has anyone else encountered this fault code and know what issues this code represents or how much they would cost to fix? Or does Passive / Sporadic mean it may not be a concern?

The owner noted it hasn’t been driven a whole lot recently, so it may be from the car sitting (I did see an answer to a similar post about PDK codes popping up when the car battery is low so maybe it’s that?).

Please let me know if any thoughts or suggestions on how to determine there are no issues prior to making a decision on purchasing! Thanks in advance for the help.

VAGfan

Sounds like the solenoid is failing, or more likely, one of the 2 "Circuit Boards" (which connect to the solenoids) has an intermittent open-circuit, which is the typical way these boards fail.

They can be relatively easily replaced by removing the transmission pan, removing the Mechatronics unit, and unplugging the old boards, and then plugging in the new boards. The boards were improved a few years ago to eliminate these open-circuit type of failures. All this can be done on a lift, with the transmission remaining in the vehicle.

This would also be an ideal opportunity to change the internal "suction" filter (behind the pan), change the external filter, and replace the fluid.

These circuit boards can be bought various places, some true OEM parts (more expensive) and some Chinese clones (less expensive).
Audi B8/B8.5 S4 Quattro 3.0T Drivetrain DSG Transmission - 0B5398009F - Mechatronics Repair Kit 0B5398009F (0B5 398 009 F) (ecstuning.com)

Audi B8/B8.5 S4 Quattro 3.0T Drivetrain DSG Transmission - 0b5398009f2KT - DL501 Ultimate Mechatronic Rebuild Kit (ecstuning.com)


Some of the kits also include some replacement solenoid valves.

If you really want his Macan, knock $4K to $5K off the asking price. But, be aware, that if the above repair kits don't fix the issue, transmission repairs/replacement can cost you alot more. The challenge is finding a repair shop that is familiar with this type of transmission, which is also used in a few Audi models (S4, S6, S7, RS5...)

slickrick

Thanks @VAGfan seems like it may be a relatively simple solution with the possibility of a more complicated issue.

Not entirely sure I’m willing to take the risk but I’ll have a conversation with the seller to see if I can knock the price down as you suggested.

Appreciate the help and I’ll report back if I end up purchasing and trying out the repairs.