The MIL light on my 2555 comes on every once in a while (always related to low RPM operation). I wanted to see exactly what code(s) were being generated, so I bought this:
Amazon.com: GXG-1987 WiFi Wireless OBD-II Mini ELM327 OBD2 Auto Car Diagnostic Scanner Tool Adapter Reader Scan Code Tester for iPhone 6S 5 iPad4 iPod mini IOS PC Windows, Android Device …: Automotive
I also bought "Torque Engine Management Diagnostics and Tools" for my Android ($5.00 from Google Play Store). I've only had to use it once, but it worked flawlessly. It was able to retrieve and clear the two codes it found (EGR-related, of course). I was also surprised that it recognized my tractor as a Mahindra 2555 and displayed several of her mechanical properties as well (engine displacement, Weight, etc.). This software can do a whole lot more than retrieve codes, but I didn't have any extra time to spare. But I'm sure I'll find time to explore its capabilities soon enough.
For only a $20 total investment, I'm able to see exactly what's going on with my engine.
Man, I wish it was that easy with my 1969 Cutlass

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