VW/Audi DQ381 / DQ380 DSG 7: P0805 Diagnostic help and solution

DSG 7 DQ380 / DQ381 Bosch (0DE / 0GC)

TCUs

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DSG 7 DQ380 / DQ381 Bosch (0DE / 0GC)

TCUs

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What does the P0805 fault code mean? 

The P0805 fault code indicates that there is a malfunction with the clutch position sensor circuit. In VAG models with a DSG 7 transmission (DQ380, DQ381, or DQ500), this is usually a mechatronics-related issue, where the internal position sensors of the wet dual clutch are not functioning properly. 

P0805 Symptoms

• The car has no power or reduced power and goes into limp mode. Only the even gears (2,4,6) and sometimes reverse work. 
• "Gearbox in emergency operation" / Transmission malfunction or other warning lights illuminated on the dashboard 
• Irregular or erratic gear changes, especially with a warm transmission

 NB: Changing the oil may provide temporary improvement, but will not resolve the underlying electronic problem. 

Related Fault Codes

• P1735 – Position Sensor for Clutch 1: Electrical Malfunction
• P1736 – Position Sensor for Clutch 2: Electrical Malfunction

These codes often appear alongside the P0805 fault, and are a strong indicator of an internal TCU failure. 

Which vehicles are fitted with a DQ380, DQ381 or DQ500

• The DQ500 (0BH / 0BT) was introduced in 2009 on the PQ35 platform, used in various front and all-wheel drive vehicles with engines that produce up to 500 Nm. 
• The DQ380 (0DE) was introduced in 2015 as a smaller version of the DQ500. Initially intended for the Chinese market, it was later used on MQB platform models with up to 420 Nm. 
• The DQ381 (0GC) was launched in 2017 for European MQB platform vehicles. Used in front and all-wheel drive models with up to 420nm

Examples of models with these transmissions

• Audi: A3 8V (2012–2020), Q2 GAX (2016), Q3 8U (2011–2018), Q3 F3 (2018–), TT 8S (2014–2023)
• Cupra: Ateca (2018–2020)
• SEAT: Ateca 5FPX (2016–), Tarraco (2018–2024)
• Škoda: Karoq (2017–), Kodiaq (2017–2024), Superb 3V (2015–2024)
• Volkswagen: Amarok, Arteon, Golf VII, Passat B8, T-Roc, Tiguan, Touran, Transporter T5/T6, Multivan

How does the DSG7 Mechatronics work, and why does it fail? 

The mechatronics system combines hydraulics, electronics and software to control the two wet clutches and seven gears. The TCU processes sensor data and regulates pressure and position. If the internal position sesnor fail, the car switches to emergency mode and loses gears.

Diagnostic Checklist 

• Check the wiring harness and connectors for corrosion, pin damage, ground connections and fuses. 
• Test drive to the operating temperature: the P0805 fault often returns after 30-60 minutes. 
• If you also see P1735/P1736, this is a further indicator of an internal TCU failure.

The Solution? Remanufacture at ACTRONICS

ACTRONICS offers a targeted remanufacturing solution for the DSG7 DQ380 / DQ381 and DQ500:

• Our unique test setup simulates and reproduces real-world driving conditions. 
• Defective components are replaced, and preventative reinforcement of weak points is applied.
• Plug & Play and supplied with a 2-year warranty

Reman vs New

• Cost Savings: Remanufacturing is cheaper than new replacements, and completed to OEM specs. 
• Quality & Warranty: Our products are supplied with a 2-year warranty and are subjected to extensive final testing.
• Sustainability: Remanufacturing uses significantly less CO₂ and raw materials than buying new. 
• Plug & Play: No learning procedure is required