P2808 moderate

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.

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Keep driving?: Short distances only
DIY difficulty: hard
Estimated cost: $300 - $1500 (parts and labor)

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.

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Read Transmission Codes

LAUNCH CRP123X (Reads All Systems)

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

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

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.