Audi Volkswagen P0C2900 TSB on DSG7 DQ381 (0GC) from 2017-2019
Fault code: P0C2900 – Activation of Additional Hydraulic Pump to Transmission Oil Unrealistic
This problem can be a very expensive repair to a customer.
We have seen several transmissions completely damaged with a big hole in the side.
Picture kindly provided by: Complete Car Service Soest
Service campaign:
Hopefully, most of these problems will be solved by the dealership since there is a service campaign on this problem.
Name of service campaign:
Audi: 34L4.
Volkswagen: 34K1.
During this campaign, the software to the transmission is updated. The software update will improve the monitoring of the additional hydraulic pump. After the update, the workshop must drive the vehicle to see if the transmission control unit (with the new software) will detect the fault code: P0C2900 – Activation of Additional Hydraulic Pump to Transmission Oil Unrealistic.
If fault code P0C2900 is stored during test drive:
The manufacture advises to replace the additional hydraulic pump with the latest improved type. This requires a removal/disassembly of the transmission since the pump is fitted inside the transmission.
If fault code P0C2900 is not stored during the test drive:
No further work needs to be done.
According to the manufacturer, it only includes transmissions with a production date before 01-10-2017.
In transmissions manufactured after 01-10-2017, an improved type of additional hydraulic pump is fitted.
We have learned that this problem can also occur in models from this period with the latest software that somehow passed the test drive after the software update.
Will the manufacture cover the cost of this repair if the car is out of warranty?
This completely depends on the car history, the relationship between customer and dealership and the country.
If the dealership can see that the service campaign is not completed at a dealership, they could refuse to pay for this.
Other things like tuning, maintenance history etc. could also play a part in the decision regarding extended warranty.
We advise all our aftermarket customers to always check for active service campaigns during regular maintenance. This can be checked on the manufacturer website or by companies offering this kind of service. When we see important service campaigns like this, we make a TSB on this in DDTSB. If you are working / doing maintenance jobs on new cars or cars, you are not yet familiar with we advice to select the category maintenance in DDTSB. Here, we show all the necessary information you need to know when you do maintenance jobs. This could also be guides on transmission oil change.
Below, we show how a customer to DDTSB would be warned about this problem:
DQ381 – The Additional Hydraulic Pump to Transmission Oil
DQ381 history
The 7 speed DSG transmission DQ381 / 0GC can be found in VAG cars from 2017 with transverse engine in both 2.0 TDI and 2.0 TFSI. In all wheel drive it can be referred to as DQ381-7A, and in front wheel drive DQ381-7F. The DQ381 transmission is a further development of the DQ380 and was introduced in 2017. The DQ380 was developed based on the DQ500 (0BH/0BT), which is used, for example, in the Volkswagen Transporter and Tiguan. The DQ380/DQ381 uses a “weaker” dimension of toothed wheel kit than the DQ500, which in return takes up less space.
The DQ381 uses a new oil pump concept than the previous DQ380. DQ381 uses a mechanical oil pump with a performance of 8 ml per rpm. In addition, an additional hydraulic pump is also used, which can supply 3.06 ml per rpm.
The additional hydraulic pump is electrically driven by the V475 and can supply the mechanical oil pump at high load.
In the start/stop phase, the additional hydraulic pump is activated, which provides a softer start-up.
Illustration from DDTSB No. 9076.
You can recognize the DQ381 by the electrical motor (V475) to the additional hydraulic pump.
So far, we have not seen this on Seat or Skoda models. Perhaps these cars were fitted with the improved pump. If you see this problem on Seat or Skoda, please let us know.
Here is page 1 of 4 of DDTSB No. 9076.
Following fault codes can also be stored because of this fault:
P060700 – Control Module Performance
P072B00 – Stuck in Reverse
P072C00 – Stuck in Gear 1
P081000 – Clutch Activation Malfunction
P0C2900 – Activation of Additional Hydraulic Pump to Transmission Oil Unrealistic
P175D00 – Clutch 1 Opens Unintentionally
These fault codes may be stored too: P175E00, P176A00, P176B00, P176C00, P176D00, P176E00, P176F00, P189900.
Additional symptoms may be that the transmission can only run in 1st-3rd-5th-7th or R-2nd-4th-6th.
Consider this if you update the software to the transmission.
There are also TSBs on software updates that will solve different shifting problems on this transmission. Note! If the software update from the service campaign has not yet been completed, you could end up with a new fault code afterwards: P0C2900 – Activation of Additional Hydraulic Pump to Transmission Oil Unrealistic. When you update the software to the latest version you
also add the enhanced surveillance on the additional hydraulic pump. Now you could have the problem that the customer is not willing to pay for it. It’s a good thing that the software now makes it possible to detect the fault before a complete transmission breakdown. However, to replace the additional hydraulic pump you need to dissemble the transmission. Hopefully, the customer is ready to pay for this. You could also hope that an extended warranty would cover this. If the customer doesn’t want to pay for this repair, some workshops choose to downgrade the transmission software. Now the transmission will drive until it completely breaks. So, consider twice before updating this transmission and speak to the customer about this issue.
