EngineLightCodes
Powertrain code

P084A Transmission Fluid Pressure Sensor/Switch H Circuit

Severity
Fix soon
Typical repair cost
$880–$5,500
Do it yourself
Shop job
Shop time
3–12 hours

Transmission fluid pressure sensor/switch H is the last of up to eight pressure inputs (A to H) in SAE J2012; the letter is the maker's choice.

How the engine computer detects it

Documented uses are rare: Mitsubishi sets P084A on its Jatco CVT8 (F1CJC/W1CJC) and Ford P084B on the 2020–23 Explorer 3.3 full hybrid. Mitsubishi uses P084A as a function check of the primary pulley pressure sensor: the module compares primary with secondary pressure and sets the code after 5 s outside the map at a steady ratio of 0.5 to 1.0. Electrical faults of both sensors come first as P0842/P0843/P0847/P0848; belt slip and wear debris in the fluid often follow, cured with a valve body or belt and pulley set.

Written from public technical sources and not yet checked by a mechanic. How we write these pages

Symptoms

  • Warning lamp on
  • Judder or slipping when pulling away
  • CVT limp mode with limited ratio

Common causes

  1. Valve body with faulty primary or secondary pressure sensor Most likely
  2. CVT belt or pulleys damaged, slip and debris in the fluid Most likely
  3. Harness or connector Possible
  4. Control module software or module Less likely

How to diagnose P084A

  1. Read every stored code with an OBD-II scanner. If misfire or fuel trim codes are there too, fix those first: they often cause this one.
  2. Inspect the parts involved: transmission fluid pressure sensor, transmission valve body, transmission wiring, transmission control module, cvt belt.
  3. Work through the causes above from most to least likely, cheapest checks first.
  4. Clear the code and drive a full drive cycle to confirm the repair held.

Vehicles that report P084A most

VehicleYearsReportsMedian miles
Mitsubishi Outlander Sport2015–20174—
Mitsubishi Lancer2016–20174—
Mitsubishi Outlander20163—

Counts of owner complaints to the NHTSA that mention P084A (11 in total), not failure rates: popular models get more complaints simply because more of them are on the road. Models with fewer than 3 complaints are left out.

Reading the code

P
Powertrain
0
Generic (SAE) code
8
Transmission
4A
Specific fault

Questions drivers ask

Can I drive with code P084A?

If the car shifts normally, drive gently to a shop. If it's stuck in one gear, slips, shifts harshly or won't move out of Park, don't drive it: have it towed.

Will my car pass an emissions inspection with P084A?

Probably not in states that test vehicles with an OBD-II scan: an emissions-related code that keeps the check engine light on is usually an automatic fail. Rules differ by state and county, so check yours.

This page is general information, not a substitute for a professional diagnosis. Repair costs are rough estimates for parts and labor and vary by vehicle and region.