P0841 on Subaru
Transmission Fluid Pressure Sensor/Switch "A" Circuit Range/Performance
P0841 on Subaru vehicles indicates transmission fluid pressure sensor/switch "a" circuit range/performance. Au7o has documented this code across 1 Subaru model — most commonly on Ascent. This powertrain code means the transmission computer detected the 'A' transmission fluid pressure sensor or switch reading out of its expected range or not matching actual operating conditions. This sensor converts hydraulic line pressure into an electrical signal the computer uses to manage shift timing and quality. An out-of-range reading can cause incorrect shift behavior, harsh or slipping shifts, or limp mode. It should be addressed to prevent drivability problems and possible transmission damage.
Common Causes of P0841
- •Low or contaminated transmission fluid
- •Faulty transmission fluid pressure sensor/switch
- •Wiring or connector problems in the sensor circuit
- •Clogged filter or restricted fluid passages
- •Worn valve body or internal pressure control fault
- •Faulty transmission control module (less common)
P0841 on Subaru by Model
Subaru Ascent(2 issues)
- TR690 CVT Chain Slip and Chain Guide Breakage (Recall WRK-21 / NHTSA 21V-955)2019-2020
A TCU programming error allows the Lineartronic CVT to engage before the drive chain is fully secured, causing chain slippage that fragments the chain guide. Owners report shudder, hesitation, irregular noises and MIL illumination; in worst cases chain breakage causes loss of motive power. This superseded the earlier WUV-07 recall and is the basis for the April 2024 class-action settlement covering 2019-2020 Ascents.
- CVT Hydraulic Pressure Sensor Harness Oxidation Causes Low Drive-Chain Tension (Recall 19V855 / WUV-07)2019
On the 2019 Ascent the mid-joint of the transmission hydraulic pressure sensor harness was built with dissimilar metals - tinplate against copper. Galvanic action forms an oxide film at that joint, and the film corrupts the pressure signal the sensor sends to the TCU. When the sensor reports a pressure HIGHER than actual, the TCU commands the valve to reduce line pressure, and the Lineartronic's drive chain loses clamping tension. Slipping chain produces noise, vibration and hesitation, and continued driving in that state leads to loss of power. Recall population was 76,842 vehicles. This is a separate campaign and a separate root cause from the later TR690 chain-guide/TCU-programming recall (21V955 / WRK-21) - that one is a programming issue at clutch engagement, this one is a corroded sensor harness.
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View P0841 across all makes →Frequently Asked Questions
What does P0841 mean on Subaru?▼
P0841 stands for "Transmission Fluid Pressure Sensor/Switch "A" Circuit Range/Performance." This powertrain code means the transmission computer detected the 'A' transmission fluid pressure sensor or switch reading out of its expected range or not matching actual operating conditions. This sensor converts hydraulic line pressure into an electrical signal the computer uses to manage shift timing and quality. An out-of-range reading can cause incorrect shift behavior, harsh or slipping shifts, or limp mode. It should be addressed to prevent drivability problems and possible transmission damage. On Subaru specifically, this code is documented across 1 model.
What causes P0841 on Subaru vehicles?▼
Common causes on Subaru: Low or contaminated transmission fluid, Faulty transmission fluid pressure sensor/switch, Wiring or connector problems in the sensor circuit, Clogged filter or restricted fluid passages, Worn valve body or internal pressure control fault. Specific causes vary by model and year — see the per-model sections below.
How much does it cost to fix P0841 on a Subaru?▼
Repair costs vary widely depending on the root cause and specific Subaru model.
Which Subaru models have P0841 documented?▼
Au7o has documented P0841 on 1 Subaru model: Ascent.