P2858 moderate

Transmission Fluid Pressure Sensor/Switch H Circuit High

The P2858 code means the vehicle's onboard diagnostic system has detected: Transmission Fluid Pressure Sensor/Switch H Circuit High. This is a moderate severity code.

My Garage →
Keep driving?
No — stop driving
DIY difficulty
hard
Estimated cost
$200 - $900 (parts and labor)
ANCEL AD310 OBD-II Scanner
Check Your Fluid First
ANCEL AD310 OBD-II Scanner

Read and clear transmission codes. Many trans codes are caused by low or burnt fluid -- check level and color before assuming the worst.

Check Price on Amazon
LAUNCH CRP123X (Reads All Systems)
Read Transmission Codes
LAUNCH CRP123X (Reads All Systems)

Basic scanners only read engine codes. This reads transmission, ABS, and airbag too.

Check Price on Amazon

Affiliate links — we earn a commission at no extra cost to you.

Common Symptoms

  • Harsh or firm shifts
  • Transmission bang when engaging drive
  • Check Engine Light on
  • Possible overheating

Probable Causes (Ranked by Likelihood)

  • Open circuit in sensor H wiring Very High
  • Disconnected pressure sensor H High
  • Corroded sensor H connector Moderate
  • TCM reference voltage fault Low

Frequently Asked Questions

Why do shifts feel harsh?

When the TCM sees a high pressure reading, it may reduce line pressure compensation, resulting in harsh engagement.

Can wiring cause this?

Yes, an open wire causes the signal to read high, making the TCM think pressure is higher than actual.

Should I check for a TSB?

Technical Service Bulletins exist for many vehicles regarding pressure sensor issues. Your dealer can check for applicable TSBs.

Mechanics Guide Step-by-step diagnosis

Step-by-Step Diagnostic Procedure

  1. Retrieve DTCs and freeze frame

  2. Inspect sensor H connector

  3. Test for open circuits

  4. Verify TCM reference voltage

Sources 1

This page is built from documented references. Verify against your own service info before repair work.

  • SAE J2012Diagnostic Trouble Code Definitions (defines the generic OBD-II code ranges)

Commonly Affected Vehicles

  • 2010-2020 Toyota Camry
  • 2012-2019 Honda Accord
  • 2014-2020 Nissan Altima
  • 2011-2020 Chevrolet Malibu

Related Codes

P2857P2859

Explore More

Search codes Vehicle-specific fixes Guides By make

Was this helpful?

Send this to whoever is fixing the car — your mechanic, or the person asking what the light means.

Browse by symptom → Read repair guides → Fixes by vehicle →