P0847 on Subaru: How to Diagnose & Fix
Transmission Fluid Pressure Sensor/Switch 'B' Circuit Low
1 Subaru model · 1 documented issue · 1 critical
P0847 on Subaru by model: symptoms, diagnosis and fix
Early Lineartronic CVT Outbacks (2010-2015) have documented internal CVT failures — most commonly valve-body faults, but also chain/pulley and pressure-control problems — that can cause harsh or delayed engagement, RPM flare, jerking, limp mode, or complete loss of drive. Subaru extended the CVT powertrain warranty to 10 years / 100,000 miles on 2010-2015 Legacy/Outback 2.5L CVT and 2015 3.6L CVT models (and related models) under bulletin 16-107-17R, while stating the extension was not in response to a specific condition. A revised/upgraded valve body is installed at repair. This is separate from the low-speed torque-converter shudder complaint; here the transmission can set fault codes and go into failsafe. Out of warranty, a full CVT replacement is a multi-thousand-dollar repair.
Common Symptoms
- Harsh or delayed engagement into gear
- RPM flare / slipping under acceleration
- Jerking or shuddering
- Transmission warning light / limp mode
- Whining or loss of drive
How to Fix
If you experience harsh/delayed engagement, flaring, jerking, or a transmission warning, scan for CVT codes and get it evaluated quickly. First verify the vehicle is within (or was serviced under) the 10-year/100,000-mile CVT Warranty Extension — if so the valve-body or CVT repair should be free; escalate to Subaru of America if a dealer initially denies coverage, since owners report success on valve-body claims. Keep CVT fluid at the correct level/spec and address any leaks promptly, as low pressure accelerates valve-body wear. Out of warranty, a rebuilt/updated valve body is far cheaper than a complete CVT unit — get a diagnosis of the specific failed component before authorizing a full replacement.
What you need to fix it
Only diagnosis- and fitment-reviewed repair parts are linked here.
- Genuine Subaru 31706AA331 CVT Control Valve Body
early CVT valve body only after TCM diagnosis proves the valve-body fault Fitment/availability: 2010-2012 Outback 2.5-liter EJ253 CVT branch; confirm VIN and production date Fitment/availability: ships in 1-2 business days with Add to Ca…
- Genuine Subaru 31825AA055 CVT Control Valve Kit
later 2.5-liter CVT valve body only after TCM diagnosis proves the fault Fitment/availability: 2013-2015 Outback 2.5-liter FB25 CVT branch; current supersession of 31825AA050-054, confirm VIN Fitment/availability: Add to Cart live when r…
- Genuine Subaru 31706AA144 High-Torque CVT Control Valve Body
2015 3.6R high-torque CVT valve body after exact diagnosis and VIN selection Fitment/availability: 2015 Outback 3.6R CVT branch within this card; current supersession of production-specific 31706AA140/141, confirm VIN Fitment/availabilit…
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Sources for this issue (3)
P0847 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 P0847 mean on a Subaru?
P0847 stands for "Transmission Fluid Pressure Sensor/Switch 'B' Circuit Low." The transmission fluid pressure sensor/switch 'B' circuit voltage is below the expected range (too low / shorted to ground). On Subaru it is documented across 1 model: Outback.
What are the most common causes of P0847?
The most common causes of P0847 are: Sensor signal shorted to ground, Faulty pressure sensor/switch B, Corroded/damaged connector, Internal TCM fault. The specific cause varies by vehicle.
How much does it cost to fix P0847 on a Subaru?
Repair costs vary widely with the root cause and Subaru model; each issue on this page carries its own estimate where one is published.
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Content compiled with AI assistance using NHTSA complaints, TSBs, and owner reports. May contain errors. Always verify with your vehicle's service manual.