Transmission Fluid Pressure Too High
The P2808 code means the vehicle's onboard diagnostic system has detected: Transmission Fluid Pressure Too High. This is a moderate severity code.
- Keep driving?
- Short distances only
- DIY difficulty
- hard
- Estimated cost
- $300 - $1500 (parts and labor)
Read and clear transmission codes. Many trans codes are caused by low or burnt fluid -- check level and color before assuming the worst.
Basic scanners only read engine codes. This reads transmission, ABS, and airbag too.
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Common Symptoms
- Very harsh shifts in all gears
- Transmission leaking from seals
- Unusual hydraulic noise
- Check engine light on
Probable Causes (Ranked by Likelihood)
- Pressure regulator valve stuck closed Very High
- Pressure control solenoid failure commanding max pressure High
- Valve body main pressure passage restriction Moderate
- TCM commanding excessive pressure erroneously Low
Frequently Asked Questions
Can high pressure damage transmission seals?
Yes. Excessive hydraulic pressure can blow out seals, gaskets, and O-rings, causing fluid leaks and potential loss of pressure in affected circuits.
Why are all shifts harsh with P2808?
High line pressure causes all clutch packs to engage too aggressively, resulting in harsh, banging shifts throughout the entire gear range.
What is the pressure regulator valve?
It controls the main line pressure by bleeding off excess hydraulic pressure back to the pump inlet. A stuck regulator causes uncontrolled pressure buildup.
Mechanics Guide Step-by-step diagnosis
Step-by-Step Diagnostic Procedure
-
Measure line pressure in all ranges
-
Test pressure regulator valve movement
-
Check pressure control solenoid operation
-
Monitor TCM pressure commands
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 RAV4
- 2012-2019 Honda Accord
- 2008-2018 Ford Escape
- 2011-2020 Chevrolet Equinox
Related Codes
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