Melatv 788 Posted June 9, 2021 Hi: That's not the news that we want to hear -- well scratching heads for sure Share this post Link to post Share on other sites
Bossdaddy 209 Posted June 9, 2021 You are probably right but it gave no problems for 20 years, I got to try and get it fixed. Share this post Link to post Share on other sites
retro 4,042 Posted June 10, 2021 Sorry I'm a bit late tonight Bossdaddy, been fishing for the last three days and just getting settled back in at home. Hang onto that loaner ECM for a bit... I'll be ready to help you find our error after getting a good nights sleep. 🙂 Share this post Link to post Share on other sites
Bossdaddy 209 Posted June 10, 2021 (edited) Good you got some time to go relax and do some fishing. Take your time this thing is not going anywhere. Edited June 10, 2021 by Bossdaddy 1 Share this post Link to post Share on other sites
retro 4,042 Posted June 11, 2021 Alright, lets try again from the top eh? With everything plugged in, transmission in Neutral, does the green Neutral light on the display light up and can you see "N" on the display when you turn the key on? Key on, while rocking the ATV back and forth, manually shift the transmission down into Reverse. Does the red Reverse light come on and can you see "R" on the display indicating reverse gear? Key on, while rocking the ATV back and forth, manually shift up into first gear. Can you see "1" on the display indicating 1st gear? Key on, while rocking the ATV back and forth, manually shift all of the way up into fifth gear. Can you see "5" on the display indicating 5th gear? Note that while you are manually shifting up through 2nd, 3rd and 4th gears the display will not indicate those gears. You will see "---" on the display... That is normal behavior on your 2001 450 while shifting the transmission manually into those gears. 1 Share this post Link to post Share on other sites
Bossdaddy 209 Posted June 11, 2021 When I thought we had found the problem I sent the meter to AKATV for a repair so I won't have it back until sometime next week. When we were working on it I do know all the lights worked correctly and the N showed up at the right time but the rest of the numbers I don't know. 1 Share this post Link to post Share on other sites
retro 4,042 Posted June 11, 2021 Ok, we can continue without the display since only the speed sensor receives it's power from the display (Black/Blue wire) connector. Lets confirm the power & grounds circuits again.... With the key off, disconnect the 4p main relay. Inside the 4p main relay harness connector measure DC voltage between the Red/White wire terminal and the Green wire terminal. You should measure battery voltage. Plug the main relay back in following this test. We poked a pin into the Red/Yellow wire during a previous test, lets do that again. Find the location where you pierced the insulation of the Red/Yellow wire and poke a pin into that hole. Turn the key on and measure DC voltage between the pin and frame ground. You should measure battery voltage. Turn the key off, remove the pin and reseal that wire following this test. Unplug the 16p shift ECM connector. Turn the key on and measure DC voltage between the Black/Green wire terminal inside the 16p harness connector and frame ground. Turn the key off following this test. Do you have a 12 volt test light Bossdaddy? Share this post Link to post Share on other sites
retro 4,042 Posted June 11, 2021 Instructions for that last test above were incomplete: 10 minutes ago, retro said: Unplug the 16p shift ECM connector. Turn the key on and measure DC voltage between the Black/Green wire terminal inside the 16p harness connector and frame ground. You should measure battery voltage. Turn the key off following this test. Share this post Link to post Share on other sites
Bossdaddy 209 Posted June 11, 2021 (edited) R/y to ground I got nothing I even went all the way to the neg post on battery I do have a light tester. B/g to ground read 12.3v Edited June 11, 2021 by Bossdaddy 1 Share this post Link to post Share on other sites
retro 4,042 Posted June 11, 2021 Ok, with the key off and everything plugged in, unplug the 5p shift ECM connector only. You'll need a jumper wire for this test, so find a length of wire that is long enough to reach from the positive battery terminal to the unplugged 5p ECM connector. Then poke one end of that jumper wire into the Black/Orange wire terminal inside the unplugged 5p ECM wiring harness connector. The Black/Orange wire is the smallest diameter wire of the 5 wires that enter the 5p connector. Attach the other end of that jumper wire to the positive battery terminal. Turn the key on. Measure DC voltage between the Red/Yellow wire terminal inside the 5p shift ECM connector and frame ground. You should measure battery voltage. Then measure DC voltage between the Red/Yellow wire terminal inside the 5p shift ECM connector and the solid Green wire terminal inside the 5p shift ECM connector. You should measure battery voltage. Turn the key off and remove the jumper wire. Share this post Link to post Share on other sites
Bossdaddy 209 Posted June 11, 2021 I did get 12.3dcv at r/y to ground and the same at r/y to green 1 Share this post Link to post Share on other sites
retro 4,042 Posted June 11, 2021 Ok, I just noticed that the 4p main relay harness connector is not sealed... so we can easily verify that those supply voltages we just measured exist while the relay and the shift ECM are plugged in. Lets confirm those again before we move on. So, plug everything back in. Turn the key on. While probing into the back of the 4p main relay connector measure DC voltage between the Black/Orange and the Green wire terminals. You should measure battery voltage. Then, while probing into the back of the main relay connector measure DC voltage between the Red/Yellow and frame ground. You should measure battery voltage. Share this post Link to post Share on other sites
retro 4,042 Posted June 11, 2021 Got a question.... Is your original shift ECM plugged in or is the loaner ECM plugged in? Share this post Link to post Share on other sites
Bossdaddy 209 Posted June 11, 2021 The loaner is plugged in. Share this post Link to post Share on other sites
retro 4,042 Posted June 11, 2021 OK, lets use your original ECM while testing. Plug your ECM in then verify voltages in the back of the 4p main relay connector as explained above. Share this post Link to post Share on other sites
Bossdaddy 209 Posted June 11, 2021 (edited) Using original EMC the b/o to g reads 0.00, the r/y to ground reads 0.03, using the loaner readings are b/o to g reads 10.98 and the r/y to ground reads 11.01, I had already gotten the reading using the loaner before I got the message to use the original. The original is plugged in now. Edited June 11, 2021 by Bossdaddy Share this post Link to post Share on other sites
retro 4,042 Posted June 11, 2021 Wow those results were unexpected! The original ECM is not sending battery voltage to the main relay coil through the Black/Orange and Green wires. While the loaner ECM is sending voltage to the relay coil through the Black/Orange and Green wires... but that voltage measures much less than battery voltage. I wonder if one of the connectors might be bad...? Or the health of the battery is poor? Gimme a few minutes to study... be right back. Share this post Link to post Share on other sites
retro 4,042 Posted June 11, 2021 Lets get the battery voltage up where it belongs before we try anything else? Connect a battery charger up to the battery then measure those same voltages again. Then swap ECMs and measure them.... Report those voltages for each ECM. Share this post Link to post Share on other sites
Bossdaddy 209 Posted June 11, 2021 Original ECM b/o to green reading 0.00 and r/y to ground reading 0.03, loaner ECM b/o to g reading 12.3 and r/y to ground reading 13.2. This is with battery charger hooked up and charging. 1 Share this post Link to post Share on other sites
retro 4,042 Posted June 11, 2021 Ok, while the battery charger is hooked up and charging and with the loaner ECM plugged in, key turned on, depress the "UP" shift button and see if it attempts to upshift? Share this post Link to post Share on other sites
Bossdaddy 209 Posted June 11, 2021 Nothing, not a click, nothing. 1 Share this post Link to post Share on other sites
retro 4,042 Posted June 11, 2021 Ok, the original shift ECM has failed... so lets test the regulator/rectifier next to see if excessive charging voltage may have fried it? For this test plug in the original shift ECM. ***Warning: If the measured battery voltage nears or exceeds 16 volts at any time during this test let go of the throttle and turn the key off. Charging system voltage exceeding 16 volts can fry sensitive electronic components*** Start the motor and let it idle in neutral. Measure the DC voltage between the positive and negative battery terminals while the motor is idling. Report that measurement. Then slowly rev the motor up to about 5000 RPM while measuring battery voltage. Report the highest voltage that is measured while revving the motor. Share this post Link to post Share on other sites
Bossdaddy 209 Posted June 11, 2021 At idle reading was 15.05v and at approximately 5000 rpms it went down to 14.43v. Volts started down immediately on acceleration. Share this post Link to post Share on other sites
retro 4,042 Posted June 11, 2021 Was your battery charger disconnected from the battery while measuring those voltages? Share this post Link to post Share on other sites