smidy21 0 Posted August 1, 2023 Hi, I have this TRX500FM bike in my workshop. Initial issue was that it wouldn't start. Followed Dianostic procedures as per service manual which resulted in failed PGM. Replaced PGM with new one and was all good for a few days. Then appeared a number of active fault codes which allowed bike to start and run but would cutout when you try to rev it. Again, followed all diagnostic procedure at per manual. Resulted in another failed PGM. Replaced the PGM again and had been good for quite a few weeks with no issues. Again, the PGM has failed as I have no gear display and won't start at all. I put the other PGM in and with start but not rev with the same active faults. I believe something is failing the PGM but can't work out what the cause is. I have checked power and grounds. Battery charge rate ect. Any help would be appreciated. Share this post Link to post Share on other sites
jeepwm69 7,619 Posted August 1, 2023 Welcome aboard. What year is the machine? Have you checked the voltage at the battery when running? A failing voltage regulator can fry a CDI/ECU pretty quickly. Share this post Link to post Share on other sites
smidy21 0 Posted August 2, 2023 Thanks for your help! It's a 2012. I have checked voltage when idling with the old PGM and its around 13.5v. I did check it on an earlier repair after I had fixed it and running at high idle and it was around the 13.5 - 14v range. But maybe at some stage it's spiking? I can't fault the wiring harness and have been through powers and grounds ect. I guess I could replace the regulator and PGM again. We pay a lot more for our parts here in Australia! Share this post Link to post Share on other sites
jeepwm69 7,619 Posted August 2, 2023 9 hours ago, smidy21 said: Thanks for your help! It's a 2012. I have checked voltage when idling with the old PGM and its around 13.5v. I did check it on an earlier repair after I had fixed it and running at high idle and it was around the 13.5 - 14v range. But maybe at some stage it's spiking? I can't fault the wiring harness and have been through powers and grounds ect. I guess I could replace the regulator and PGM again. We pay a lot more for our parts here in Australia! Sounds like you've covered the regulator issue. If they fail you usually get no spark or high voltage. See now that you actually mentioned that in the initial post. We have some guys on here who are pretty good at electrical stuff. @Melatv and @retro, along with @AKATV. I just haven't seen many failed ECU's, and certainly not 2-3 in a row. What does an ECU run down there in Aussie dollars? Any chinese electrical parts on the wheeler at all, or is everything OEM? Share this post Link to post Share on other sites
