# Creating Checksum Byte on PMU24 **URL:** \ **Category:** PMU\ **Tags:** how-to\ **Created:** [May 16, 2025, 4:49am UTC](https://community.ecumaster.com/t/creating-checksum-byte-on-pmu24/3710 "2025-05-16T04:49:50Z")\ **Posts on this page:** 1\ **Showing post:** 5
**Author:** ![eRoverMike](https://avatars.discourse-cdn.com/v4/letter/e/898d66/32.png) [@eRoverMike](https://community.ecumaster.com/u/eRoverMike)\ **Post date:** [October 9, 2025, 1:32am UTC](https://community.ecumaster.com/t/creating-checksum-byte-on-pmu24/3710/5 "2025-10-09T01:32:55Z")
Plus one for this entire topic, and the potential canbus export enhancements. Having control over individual bit values would also be key. For my application, I am looking to use the PMU to send canbus messages to an OEM ECU based on throttle inputs, FNR switching, etc. and it needs a CRC in the last byte based on the bits in the message. There is a counter in the message, too, so does not seem like I could (practically) generate a table of lookup values. Of course, the CRC needs to follow the unique OEM CRC8 method, which has a polynomial 0x85, so also not simple. It uses XOR. As @AaronPD said in [this post](https://community.ecumaster.com/t/can-i-make-reactive-canbus-export-cycling-timers/3417), I could add a microcontroller to do this work (and many do), but the PMU is much more robust, capable, and has all the right inputs than a separate Arduino or other such controller. Would be amazing if the PMU could have (or already has) this kind of canbus export capability. --- _[View the full topic](https://community.ecumaster.com/t/creating-checksum-byte-on-pmu24/3710)._