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P2820CriticalPowertrain

P2820: How to Diagnose & Fix — Pressure Control Solenoid "J" Performance or Stuck Off

2 vehicles · 2 makes

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How to diagnose and fix P2820: 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.

Subaru Ascent · 2019–2020

Link to this issueError Codes:P0700P0841P2820

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 This superseded the earlier WUV-07 recall and is the basis for the April 2024 class-action settlement covering 2019-2020 Ascents.

Common Symptoms

  • shudder on acceleration
  • hesitation
  • whining or rattling from CVT
  • CEL/MIL illuminated
  • loss of forward propulsion
  • P0700 / P2820-type codes

How to Fix

Verify recall WRK-21 / 21V-955 is completed at a Subaru dealer (free TCU reprogram, chain-slip data inspection, replacement of CVT if slippage is found, plus oil cooler add). Class-action settlement (final approval April 18, 2024) extends powertrain warranty to 8yr/100k for affected VINs and provides reimbursement vouchers ($400-$750) for prior repair attempts.

Typical repair cost:$0 - $6,500
Sources for this issue (3)
  • NHTSA Recall 21V-955 / WRK-21 CVT Chain Guide Breakagerecall
  • RECALL: WRK21 / NHTSA 21V955000 - Ascent CVT Chain Guide Breakageforum
  • Subaru Ascent CVT Lawsuit Settlement Informationarticle

Research This Issue

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Community Reported
High ConfidenceVerifiedReviewed Jun 2026

Acura MDX · 2016–2019

Link to this issueError Codes:P0729P0732P0734P2820

The ZF 9HP 9-speed automatic introduced on the 2016 MDX suffers from documented hesitation, harsh shifts, lurching, and unexpected downshifts/deceleration. Drivers report the vehicle hesitating from a stop, banging into gear, or briefly losing power. Software miscommunication between TCM, ECM and throttle control is the alleged root cause; a class action was filed alleging Honda knew of the defect from 2015.

Common Symptoms

  • Hesitation from a stop
  • Hard or banging shifts
  • Unexpected downshift while cruising
  • Brief loss of power
  • Lurching at low speed

How to Fix

Have dealer apply latest TCM/PGM-FI software updates first (covered by powertrain warranty). If symptoms persist, request fluid replacement and dealer escalation; document everything for lemon-law/class-action relief. Avoid jerky throttle inputs while cold.

Typical repair cost:$0 - $6,500
Sources for this issue (3)
  • Honda Class Action Alleges Transmission Defect (2016-2019 Acura MDX)article
  • Acura RDX, MDX and TLX Transmission and Infotainment System Defectsarticle
  • 2017 MDX Advance sluggish & jerky ZF9 Transmissionforum

Research This Issue

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Community Reported
High ConfidenceVerifiedReviewed Jun 2026

Find P2820 by make

Browse every documented model and issue for your make.

Acura · 1 issueSubaru · 1 issue

P2820 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 P2820 mean?

P2820 stands for "Pressure Control Solenoid "J" Performance or Stuck Off." This code means the transmission control module determined that pressure control solenoid "J" is not responding as commanded or is stuck in the off position. These solenoids regulate the hydraulic pressure that applies the transmission's clutches and bands during shifts. When this solenoid is stuck or underperforming, the result is typically harsh or incorrect shifting, slipping, or limp mode. It can stem from a mechanical sticking of the solenoid/valve as well as fluid or electrical issues.

What are the most common causes of P2820?

The most common causes of P2820 are: Stuck or faulty pressure control solenoid "J", Low or contaminated transmission fluid, Debris in the valve body sticking the solenoid, Internal valve body wear/fault, Wiring or connector problems to the solenoid, Faulty transmission control module. The specific cause varies by vehicle.

How much does it cost to fix P2820?

Repair costs vary widely depending on the root cause and vehicle.

Which vehicles are affected by P2820?

Au7o has documented P2820 across 2 vehicle models from 2 manufacturers: Acura, Subaru.

Related codes

  • P0020 · Camshaft Position 'A' Actuator Circuit (Bank 2)
  • P0034 · Turbocharger/Supercharger Bypass Valve Control Circuit Low
  • P0035 · Turbocharger/Supercharger Bypass Valve Control Circuit High
  • P003A · Turbocharger/Supercharger Boost Control 'A' Position Exceeded Learning Limit
  • P0045 · Turbocharger/Supercharger Boost Control Solenoid Circuit/Open
  • P0046 · Turbocharger/Supercharger Boost Control 'A' Circuit Range/Performance
  • P0047 · Turbocharger/Supercharger Boost Control Solenoid Circuit Low
  • P0048 · Turbocharger/Supercharger Boost Control Solenoid Circuit High
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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.

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