Tuner will not connect to ecu

12 replies to this topic
  • rwebb35

Posted February 11, 2015 - 07:17 AM


Today is the first time I have tried to use my tuner since I removed the battery & starter. 12 wr 450. It will not connect to ecu. Bike runs great, set with all 0's on comp. ecu. I wanted to change the map but as I said will not connect. Any thoughts? Thnx!

  • rwebb35

Posted February 11, 2015 - 08:39 AM


Just figured it out. Bike has to be running for the connection to occur (duh)! Works perfect!

  • rwebb35

Posted February 19, 2015 - 06:07 PM


Well, works perfect in monitor mode only. Tried to send a new map to ecu today and all I get is failure to connect to ecu. Any ideas?

  • AtomicGeo

Posted February 19, 2015 - 06:30 PM


Mine connects with the ignition switch on (doesn't have to be running).  It should be able to scroll over from the monitor mode to settings mode.  Can you gett it to do that?  You have to hit the enter button to choose the settings mode.

  • rwebb35

Posted February 19, 2015 - 06:51 PM


Does not connect with the ignition switch on. Bike has to be running to use monitor mode, which works fine but only if bike is running. Send mode does not work with or with out bike running. This has to be an issue with the removal off the battery. Anyone else out there without a battery able to send maps to ecu?

  • AtomicGeo

Posted February 19, 2015 - 06:57 PM


I didn't catch that you removed the battery...so, you are connected to rectified AC to power the tuner.   Are you before or after the diode (# 39 on the wiring diagram)? Or did you remove the diode too?

Edited by AtomicGeo, February 19, 2015 - 06:57 PM.

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  • rwebb35

Posted February 19, 2015 - 07:18 PM


Unfortunately this is over my head. I will have to ask these questions to the guy that did the work. I did talk to him about it today and he is stumped. Thank you for your help and I will get back to you with some answers.

  • Monk

Posted February 19, 2015 - 07:24 PM


Any reason you couldn't connect the battery back up and see if that is the issue?

  • rwebb35

Posted February 19, 2015 - 07:45 PM


Yes that will be done soon and I will get back and let you guys know.

  • AtomicGeo

Posted February 19, 2015 - 08:12 PM


looking at the wiring diagram, I see that you cannot just disconnect the battery w/o compensating for the lost battery voltage negative terminal.  If you disconnected the battery, then the only other place for a quasi-DC voltage (i.e., rectified AC) is to connect the black wire for the power tuner connection somewhere to the black wire rectifier/regulator negative..  


Edit:  I see that the black wire on the tuner is the negative on the battery which is ground.  On the other side, the ride wire on the tuner is hot, but needs to be on the negative side of the diode I asked about earlier.  I would try grounding the black wire on the tuner and see if it works.

Edited by AtomicGeo, February 19, 2015 - 08:28 PM.

  • Dexter42

Posted February 19, 2015 - 08:21 PM


Lithium batteries on the tuner are a must, also if you turn the bike on with the tuner connected the tuner will turn on automatically, leave the tuner on and shut the bike off- does the tuner remain on or does it shut off too?

Edited by Dexter42, February 20, 2015 - 10:32 AM.

  • rwebb35

Posted February 20, 2015 - 06:30 AM


Yes I am using lithium batteries. Not sure to your second question, I think I have been manually turning tuner off before shutting bike off. I will try this. I am out of town for next few days and will not have time to r & d, will get back to you guys soon. Again thanks for all the help. I would really like to get this working the way the system is designed to work. Yamaha does advertise that the bike comes with a capacitor and is able to run without the battery. I just have to figure this out, thanks for your patience.

  • Wristrockit

Posted February 21, 2015 - 08:35 PM


With both the bike and the tuner off, connect the tuner to the ECU. After it is connected to the ECU turn the ignition switch on. The tuner will then power up, on it's own, and show that it is linked to the ECU. After that you can load maps. The monitor mode works while the engine is running.


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