EPDM & ENGINE DIAGNOSTICS 
Models 
NXT20 and NXT22
Purpose 
The EPDM is a solid state engine fuse block designed for all 
MasterCraft boats to make engine diagnostic checks easier and 
more convenient for quick, on the water fixes. 
Location 
The EPDM (Engine Power Distribution Module) screen is accessible 
via the standard NXT Non-Touch Screen. To reach the EPDM screen, 
press the Menu Quick Access Key to bring up the settings menu. On 
the settings menu, scroll down to and select EPDM Diagnostics.  
Operation
The EPDM screen displays critical engine and electrical system 
operating information. Amperage draw and digital switch status 
are displayed on the EPDM screen for each engine function. Digital 
switch status is designated by either a green, red or gray indicator. 
•  A green indicator denotes that the digital switch is  
functioning properly. 
•  A red indicator denotes that there is a problem with the digital 
switch and it has tripped . 
•  A gray indicator denotes that the digital switch is currently 
unused or not receiving power.
To reset a tripped digital switch, scroll down to the tripped fault and 
press RESET FAULT. To reset the entire EPDM, press RESET ALL in 
the bottom right portion of the screen. 
If a digital switch continues to trip multiple times in one outing, it is 
a sign of a larger electrical issue and the boat should be taken to an 
authorized MasterCraft dealer for diagnosis and repair.  
 
 
 
The EPDM and digital switches are designed to protect the engine 
and electrical system from damage. If a switch has tripped and 
continues to trip even after resetting the EPDM, it may be a 
symptom of a larger electrical issue, and the boat should be taken 
to an authorized MasterCraft dealer for servicing.
2021MCOwnerManualFINAL.indd   201 8/26/20   1:52 PM