Jan 27, 20223 min read

Audi DSG 7 Speed S-Tronic Circuit Board Failure. (0B5 - DL501 Wet Clutch) | Eco Torque

Updated: Apr 13, 2022

A very common issue we see here at Eco Torque's workshop, is the circuit board failure on the mechatronic units with the larger Audi range, including the A4, A5, A6, A7, Q3, Q5, A5 & RS variants.

The article below will list some of the faults and symptoms relating to this issue and the parts required to rectify the fault.

So it is important at this point to establish if this article is the correct one for your issue. This is because there are three types of 7 speed DSG system out there and this fault only applies to one of those. If you vehicle model is not listed above or if you have and engine size of under 2000cc then this particular fault does not apply to your DSG system. Please check out our guide on the smaller 7 speed dry clutch DSG system here.

In this article we are going to look at the faults that occur specifically with the mechatronics circuit board and what that translates to in real world scenarios. The board itself fails internally and can not be repaired itself, however luckily this is a well known issue and has a set of replacement parts available to get the vehicle back on the road.

Fault Codes & Symptoms
Replacing The Circuit Board
Parts Required.

Fault Codes & Symptoms

The issues caused by a failing mechatronic circuit board on the 0B5 can cause some very distinctive symptoms and fault codes. Common Symptoms:

Juddering in D or R when pulling away.
Juddering when down shifting from 2nd to 1st.
Juddering when selecting D or R.
Delayed vehicle movement/crawling when in R.
Excessive lowering of engine revs when changing from 2nd to 1st gear.
Excessive lowering of engine revs when selecting D or R.

Fault Codes Present/Logged:

Error message on dashboard: (Gearbox Malfunction, You Can Continue Driving.)
P17D8 - Torque limitation because of clutch temperature.
P0726 - RPM signal of engine control unit, implausible signal.
P174B - Valve 4 in the sub-gearbox 1, electric fault.
P174F - Valve 4 in the sub-gearbox 2, electric fault.
P179C - Main pressure valve, electric fault.
P179D - Coolant oil valve electrical fault.
P174C - Partial transmission 1 valve 2 Electrical error.
P174A - Valve 3 in the sub-gearbox 1, electric fault.
P174E - Valve 3 in the sub-gearbox 2, electric fault.
P1740 - Clutch temperature monitoring.
P17E1 - Gear positioner 2 mechanical malfunction.
P17E0 - Gear Actuator/Selector 1 (mechanical error).
P173E - Valve 1 in Transmission part 1 – Electrical Malfunction.
P174D - Valve 2 in Transmission part 2 – Electrical Malfunction.
P173F - Valve 2 in Transmission part 1 – Electrical Malfunction.
P176B - Gear Selector 2 Cannot be Regulated.
P176D - Gear Selector 4 Cannot be Regulated.
P176C - Gear Selector 3 Cannot be Regulated.
P176A - Gear Selector 1 Cannot be Regulated.
P17D6 - Clutch 1 Pressure too High.

Replacing The Circuit Board

*It is essential this repair is completed by an experienced professional.*

This component replacement requires specialised tools and diagnostic equipment. The mechatronic and subsequent parts can easily be damaged if not performed correctly and will result in additional costly repairs.

The parts below are essential for completing this repair. Please note that special attention to the swarf contamination in the oil is required. Excessive swarf can indicate clutch damage and will block & damage any new solenoids that are installed. If swarf content is particularly, the clutch pack must be replaced first before completing this repair.

After installation has been completed, basic settings of various components must be performed as well as driving adaptations. A high level diagnostic machine is required to complete this. Failure to perform this procedure correctly or at all will cause irreparable damage to the transmission. A more in depth step by step guide on replacing the board will be available to purchase from Eco Torque at a later date.