P172A: How to Diagnose & Fix — Auxiliary Transmission Fluid Pump Reverse Rotation
2 vehicles · 2 makes · $1,200-$4,500 repair
How to diagnose and fix P172A: most-reported vehicles
Ranked by owner reports. Each card gives the symptoms, how to confirm the cause, the fix, parts and sources for that vehicle.
Audi A1 · 2011–2016
A1s fitted with the 7-speed dry-clutch S tronic (DQ200, VAG code 0AM) automatic suffer mechatronic (valve body / hydraulic control unit) failures. A design flaw in the valve body's accumulator/canister wall can crack and lose high hydraulic pressure, while the dry clutch packs wear and cause juddering. This led to a VAG recall covering A1s built roughly 2011-2016 (part of a wider ~80,000-vehicle UK action). Failure can cause sudden, complete loss of drive.
Common Symptoms
- Judder / harsh 1st-to-2nd shift at low speed
- PRNDS / gearbox warning flashing on dash
- Erratic or jerky gear changes
- Sudden loss of drive or no drive
- Limp-home mode
How to Fix
Recondition or replace the mechatronic unit with the superseded/uprated valve body, update the transmission control software, and inspect/replace the clutch pack if worn. Check the recall has been completed on any used purchase. Regular DSG service (fluid for wet-clutch variants) helps; the dry DQ200 valve body fix is the core remedy.
Sources for this issue (1)
Skoda Octavia · 2008–2020
The DQ200 7-speed dry-clutch DSG automatic fitted to many petrol Octavias is widely reported to fail. Owners experience the gearbox refusing to engage drive or reverse, jerking and 'hunting' between gears, juddering when pulling away, and limp-home/warning lights. Root causes are the mechatronic control unit (electro-hydraulic valve body) and premature dry-clutch wear; metallic wear particles can also corrupt the internal sensors. A 2014 VW Group action changed the DSG fluid spec, but failures persisted on higher-mileage cars. This is a shared VW-Group platform problem (also Golf, Polo, A3, Leon) that genuinely affects the Octavia.
Common Symptoms
- Jerking or juddering between gears
- Refuses to engage drive or reverse
- Gearbox/transmission warning light
- Limp-home mode
- Clunking or hesitation when pulling away
- Hissing noise from transmission
How to Fix
Have the gearbox fault-read promptly at first sign of juddering or gear-selection errors. Mechatronic units can often be rebuilt/replaced rather than fitting a whole gearbox; clutch packs and the dual-mass flywheel are replaced as needed. Keep to the DSG oil/filter service interval (approx. every 40,000 miles). Many specialist gearbox firms repair the mechatronic for far less than a main-dealer full-gearbox quote.
What you need to fix it
Only diagnosis- and fitment-reviewed repair parts are linked here.
- Sachs 3000943001 DQ200 0AM dry dual-clutch pack
replace a diagnostically confirmed worn DQ200 dry clutch, not a failed mechatronic Fitment/availability: Skoda Octavia with confirmed 0AM DQ200 and CBZB, CAXA, CDAB or CDAA engine as explicitly listed; confirm VIN, transmission generatio…
As an Amazon Associate, we earn from qualifying purchases; other part links may also earn au7o a commission. Confirm fitment by VIN before buying.
Sources for this issue (3)
Find P172A by make
Browse every documented model and issue for your make.
P172A code reference
General diagnostic-code context. The code alone does not confirm a cause for your vehicle; use the applicable issue card and its sources.
Frequently asked questions
What does P172A mean?
P172A stands for "Auxiliary Transmission Fluid Pump Reverse Rotation." P172A is a manufacturer-specific powertrain code (most commonly seen on Subaru CVT-equipped vehicles) indicating that the auxiliary (electric) transmission fluid pump is rotating in reverse. The auxiliary pump maintains transmission/CVT fluid pressure, so reversed rotation reduces hydraulic pressure and can cause shifting and engagement problems. The transmission control module sets this code when it detects the pump is not turning in the commanded direction.
What are the most common causes of P172A?
The most common causes of P172A are: Faulty auxiliary (electric) transmission fluid pump or its motor, Leaking O-ring on the electric oil pump relief valve allowing CVT fluid into the pump motor, Damaged, corroded, or shorted wiring/connectors to the auxiliary pump, Faulty pump control module or transmission control module (TCM), Low or degraded transmission/CVT fluid. The specific cause varies by vehicle.
How much does it cost to fix P172A?
Repair costs for P172A range from $1,200 to $4,500, depending on the vehicle and root cause.
Which vehicles are affected by P172A?
Au7o has documented P172A across 2 vehicle models from 2 manufacturers: Audi, Skoda.
Content compiled with AI assistance using NHTSA complaints, TSBs, and owner reports. May contain errors. Always verify with your vehicle's service manual.