P173A: Gear Selector Position Sensor 1 Signal Implausible (DSG Mechatronic)
2 vehicles · 1 makes · $900-$5,500 repair
Most Reported On
P173A is an OBD-II diagnostic trouble code meaning “Gear Selector Position Sensor 1 Signal Implausible (DSG Mechatronic).” P173A is a VAG (VW/Audi/Skoda/Seat) manufacturer-specific transmission fault code, set by the DSG/dual-clutch automatic transmission control module (mechatronic unit). It means the control unit received an implausible or out-of-range signal from gear selector/gear position sensor 1, so it can no longer reliably confirm which gear is engaged. It is part of the related P173A-P173D family of internal mechatronic position-sensor faults and commonly accompanies erratic shifting, a transmission warning light, or limp mode. This code is most commonly reported on 2008-2020 Volkswagen Touran, and 2007-2016 Volkswagen Eos (DSG automatic), with repair costs ranging from $900 to $5,500.
Common Causes
Typical Repair Cost
Based on 2 documented vehicle-specific issues. Actual cost depends on root cause and vehicle.
Diagnostic Tools
To diagnose P173A, you'll need an OBD-II scanner. Here are our recommendations at every price point.
ANCEL AD310 Classic OBD-II Scanner
by ANCEL
A simple, affordable code reader that reads and clears check engine codes. Great for quick diagnostics on any OBD-II vehicle (1996+).
- Read & clear engine codes
- View freeze frame data
- I/M readiness status
- No batteries or app needed
BlueDriver Pro Bluetooth Scanner
by BlueDriver
Bluetooth OBD-II scanner with a free companion app. Provides enhanced diagnostics, smog readiness, and repair reports sourced from a database of verified fixes.
- Enhanced diagnostics (ABS, SRS, transmission)
- Repair Reports with verified fixes
- Smog check readiness
- Free app (iOS & Android)
LAUNCH CRP123X OBD-II Scanner
by LAUNCH
A professional-grade handheld scanner that reads all four major systems (engine, transmission, ABS, SRS) with live data streaming and graphing.
- Engine, transmission, ABS, SRS diagnostics
- Live data stream & graphing
- AutoVIN for vehicle identification
- Free lifetime updates via Wi-Fi
Autel MaxiCOM MK808S Diagnostic Tool
by Autel
Shop-level diagnostic tablet with bi-directional control, active tests, and full system coverage. Ideal for serious DIYers and small shops.
- All-system diagnostics (25+ modules)
- Bi-directional control & active tests
- Oil reset, EPB, BMS, TPMS, injector coding
- 7-inch touchscreen with Android OS
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FAQ
What does P173A mean?
P173A stands for "Gear Selector Position Sensor 1 Signal Implausible (DSG Mechatronic)." P173A is a VAG (VW/Audi/Skoda/Seat) manufacturer-specific transmission fault code, set by the DSG/dual-clutch automatic transmission control module (mechatronic unit). It means the control unit received an implausible or out-of-range signal from gear selector/gear position sensor 1, so it can no longer reliably confirm which gear is engaged. It is part of the related P173A-P173D family of internal mechatronic position-sensor faults and commonly accompanies erratic shifting, a transmission warning light, or limp mode.
What are the most common causes of P173A?
The most common causes of P173A are: Failed or degraded gear position (magnetic) sensor inside the mechatronic unit, Faulty mechatronic unit / transmission control module circuit board (thermal damage), Contaminated or worn transmission fluid carrying metal particles past the sensor, Damaged wiring, corroded connectors, or poor grounds to the transmission, Broken or worn internal shift fork/selector magnets, Manufacturing defects in early DSG (e.g. 0AM/DQ200) mechatronic units. The specific cause varies by vehicle.
How much does it cost to fix P173A?
Repair costs for P173A range from $900 to $5,500, depending on the vehicle and root cause.
Which vehicles are affected by P173A?
Au7o has documented P173A across 2 vehicle models from 1 manufacturers: Volkswagen.
Sources (6)
- articleDSG 7 / DQ200 Mechatronic Repair – ECU Testing
- article7 Speed DSG Gearbox Problems | Mechatronic Faults | DSG Clutch Pack – Eco Torque
- articleHas Volkswagen sorted all of the DSG issues? – Honest John
- Forum2010 Eos transmission/mechatronic issues — Volkswagen Eos Forum
- Forum2008 VW EOS DSG Transmission Issues — Volkswagen Forum
- RecallVolkswagen Eos Recalls (incl. DSG temp sensor 09V333000) — Cars.com
Content compiled with AI assistance using NHTSA complaints, TSBs, and owner reports. May contain errors. Always verify with your vehicle's service manual.