Products Showing Parts for — {{ }}

No Results Showing Parts for — {{ }}

Duramax, Tech Talk

Keep Line Pressure Consistent in Your Duramax

Posted on by


Achieve optimal and consistent line pressure that will improve shift quality in your Allison transmission with the XDP EPC Solenoid Fooler Plug XD345. This solenoid plug will enhance the performance and life span of the Allison transmission in your GM 6.6L Duramax LML and L5P


How The EPC Solenoid Works

The function of the EPC Solenoid is to increase line pressure during shifts. In a normal shift, the line pressure can increase up to 230 PSI. But once the shift is complete, the pressure drops back down to about 80 PSI. At 80 PSI of line pressure, your Allison can’t handle the added stress from aftermarket upgrades, or any added power on your truck. So how do we keep line pressure consistent in your Duramax?

What can a Fooler Plug do for your Duramax?

The XD345 EPC Solenoid Fooler Plug corrects low line pressure issues by installing in place of the factory solenoid in the valve body.  This way, your transmission effectively operates at 230 PSI all the time. The line pressure increase helps to eliminate clutch slippage, poor shifting, and helps to extend the life of your transmission. This will keep line pressure consistent in your Duramax! The installation is simple. For a complete step by step, consult the XD345 installation guide. Note that this product should not be used in conjunction with transmission tuning or other pressure adding modifications.  

Before you experience line pressure issues in your transmission upgrade your 6.6L Duramax LML or L5P. Go to or contact your local dealer to get one of your own. 

EPC Fooler Plug CTA


Save $20 on your order of $250 or more*! Use Code MDAY2024
Offer ends 5/28. *See website for brand and product exclusions. Retail customers only.