ChrisX

Success! I was able to adjust my salvage odometer and learn a bit how it increments miles and hours. So sharing below gained experience. I highly recommend to see this article about ODO programing: https://www.instructables.com/DIY-Odometer-Reprogramming/ Here are my observations based on 2001 TRX500FA odometer IC2 (93c46) eeprom dump: Eeeprom chip has beer desoldered from ODO main board and read on eprom programmer with using SOP8 clip. MILEAGE DATA: - it looks like [Major ODO data] are stored close to the end of a dumped code (offests:0x00000060 to 0x00000070). - they are organized into 6 hex segments 8 bytes each. - each segment has the same content. - within a each segment first 4 bytes are [Major ODO data] next 4 bytes are their checksum in reversed HEX example: segment value [01 B7 FE 48] 01 B7 = [Major ODO data] FE 78 = checksum of 01 B7 in reversed hex (where: 0=F, 1=E, 2=D, 3=C, 4=B, 5=A, 6=9, 7=8 ...etc) - [Major ODO data] after decimal conversion are very close to values displayed by odometer - Odometer Display 6946 miles - hex [01 B7] = dec 439 x 16= 7024 miles - each change of Major ODO data by 1hex incerments displayed mileage by 95 miles example: [00 01 FF FE] = ODO is going to display (95 miles) where [FF FE] is just a checksum of [00 01]. I didn't investigate how Minor ODO data are stored and how extracted from Major ODO data. I was able to adjust very closely desired mileage by minipulating increments of 95 of Major ODO. HOURS DATA: - seem to be organized similar way like milegae data. - stored above mileage segments area (offests:0x00000040 to 0x00000050). - they are organized into 6 hex segments 8 bytes each. - each segment has the same content. - within a each segment first 4 bytes are hours and next 4 bytes are their checksum in reversed HEX example: Odometer Display 27238 hours hex [06 AA] = dec 1706 x 16= 27296 hours code segment [06 AA F9 5E] where F9 5E is just checksum of 06 AA in reversed hex. - each change of Hours code data by 1hex incerments displayed hours counter by 9.5 hours [00 01 FF FE] = ODO is going to display (9.5 hours) where [FF FE] is just a checksum of [00 01]. Feel free to correct or add more info to my findings. Info about minor data extraction would be very intersting! God bless to all good people helping me in this repair adventure 🙂

Sharing progress of my project and experience gained: Before: After (new polarizing filter - cut to size from sheet orderd on Amazon) Tools used: - guitar pick - plastic pry bar ( from smartphone repair set) - isopropyl alcohol - guitar pick used to lift and separate the damaged filter, - isopropyl use to soften filter glue and LCD cleanup - pry par used to scrape glue from LCD screen. Note: Filter glue is very sticky. Isopropyl alcohol did majority of job for me. It softened the glue but not disolved it entirely. It helped me to separate the filter from the screen. It helped also to remove rest of the filter glue from the glass. I had to gently scrape the glue (multiple times) using sharp edge of plastic pry bar. Every time before scrapping I poured few drops of isopropyl alcohol. It really made all work easier for me. Finally whet I started to see bare LCD glass, the layer of the glue become so thin, that I was able to remove it with wet alcohol cloth. I did it first time so don't take my words as way of doing it. Thanks God all worked fine for me ! Tons of thx to all good people helping me in this repair adventure 🙂 My next project step would be eeprom and mileage change.

Do you use any heat or chemicals to remove the old filter ?

TY !!! Is there any specifc polarizing filter i have to look or any from Amazon will work ? How to remove polirizng filter w/o damaging the LCD? Please share any tips and tricks.

Bingo! Found cold solder joint in CN1 connector Green (G) = GND Black/Brown (Bl/Br) =12V+ I have a few more questions: 1. This salvage odo LCD has some sort of brownish color. Most likely this tan is due to Sun damaged polarizning filter. Which filter to choose out of many available in Amazon ? 2. I have to adjust miles and hours to my orginal faulty TRX odmeter. I'm assuming this data are stored inside IC2 (93c46) EEPROM. Can I program this eeprom on board or it has to be desoldered from PCB for programming ?

Thank you for guidance. For troubleshooting - does odometer need to be connected to ECU (powered via TRX wiring harness) in order to show anything on the display ? Will I get anything displayed on LCD ? when I just power it up on my bench using lab power supply (12V + current protection..etc) ?

Hi AKATV Would you please briefly describe how to reporogram odometer which lost the code? I have 3 x TRX500FA 2001. In one of them odometer seem to lost the code. It powers up but display doesn't show anything ( no water damage, already cleaned, pcb/lcd terminals and swapped between machines). Is there any way to use i.e Jtag and read code from working odometer and save it to the faulty one? I have access to flash programmer also. Can you please briefly describe the procedure or point me to any url explaining it ? Regards Chris

This information is for TRX500FA diy'ers If you are trying to rebuild TRX500FA fornt diff. and looking for good quality and (5+ times cheaper) replacement for band boots: (38) BAND, BOOT (D27) 91302-HM7-A00 (42) BAND, BOOT (D20) 91303-HM7-A00 Here is some hint ACE Hardware metric orings #56264A and #56268E are perfect fit ! Just sharing, I thought it maybe usefull for somebody

Just want to confirm. Engine has been rebuild ( +1 bore, new piston, new crank, new valves), Used the same camshaft. All sounds now very nice and quiet.

If you have not working or damaged ECU for Honda TRX500FA and you don't need it, please consider donating it for ATV tinkering and experimental project. I'll post all the progress with pics on this forum Regards Chris

Hi I have 2003 TRX500FA. Camshaft decompressor in my TRX moves freely but it seems to be clunky and noisy. see YT video: clunky decompressor motor noise Can you tell me please if this is normal or I should replace the camshaft ? I appreciate your help Chris

Does 2004 TRX400FGA and 2004 TRX500FGA instrument clusters share the same LCD display ? I see bare LCD displays available in the Internet (Ebay). Looking for cheap way of repairing display in my trx500 odo.

Price for 1Gal is quite high IMHO. Is it worth the money? Do you have any pictures before and after the cleaning ?

Could you please share your experience with ultrasonic ATV engine parts cleaning solution ? Below are results of my experiments: - CLR (1:4 ditsilled watter) it works very well for alluminum cleaning from caked dirt and oil. Alluminum parts are failry bright and shiny (spotty sometimes). Unfortunetelly CLR makes damage to steel parts (bolts, polished surfaces, beraings, shaft ...etc). They bacome dull black, some of them even rust. - ZEP orange degresser (1:4 ditsilled watter) is not so destructive but makes aluminum dark and doesnt remove everything (caked dirt/oil). - Diesel fuel bath fairly cleans loose dirt and oil. Very well lubricastes and penetrates the part fr storage (stinks terrible for me) - Gasoline removes well any grease,drit, oil (sort of like carb cleaner). It doesnt work too effectively against baked oil and dirt. ( stinks, flamable) Dremel with brass wire brush or very soft steel wire is what brings in my case shine to alluminium parts. I would be more happy to use entirely chemical process. Please share your experience.

I just spoke with Brian. Apparently my Hondamatic had a differnet history than I was speculating. Most likely the Pressure Control Valve popped up and damaged the revolvel. Luckily all bearings seem to be ok. In other words I have to find a donor hondamatic with a good core and then continue assembly.