ECU - reflash or replace

Wheelin

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The cruise was quitting on my S10 while in operation. Front brake switch was already replaced under recall, but the problem still reared its head. I took the bike into the dealer. They used their diagnostic tool and got 4 codes back. I’ve not yet retrieved the bike, but they want to replace the ECUA, and the part alone costs $1385. I don’t have details on all the codes yet.
My question: would reflashing the ECU fix the problem? Should I just replace the ECU? Or should I just get a throttle lock and hope that the ECU doesn’t break in other ways?
 

thughes317

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Might want to get a 2nd opinion from another repair shop, the chance that ECU went south is highly unlikely. There are other inputs that can affect CC operation: rear brake switch, clutch switch, throttle linkage switch, etc. There is a diagnostic mode accessible on your bike, I would recommend obtaining a FSM and digging in for yourself.
 

WJBertrand

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If they're paying for the ECU maybe let them try it. I'm betting that's not the problem though. If you're paying definitely eliminate the factors that thughes317 mentions above first. Will the dealer share the codes they found with you? If so, many of us have the factory service manual and can look them up for you.
 

Wheelin

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If they're paying for the ECU maybe let them try it. I'm betting that's not the problem though. If you're paying definitely eliminate the factors that thughes317 mentions above first. Will the dealer share the codes they found with you? If so, many of us have the factory service manual and can look them up for you.
I’ll see if I can get the codes when I pick the bike up tomorrow. My thought is that if I'm paying them for their time, supplying the codes is the least that they can do. Thanks!
 
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Wheelin

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Might want to get a 2nd opinion from another repair shop, the chance that ECU went south is highly unlikely. There are other inputs that can affect CC operation: rear brake switch, clutch switch, throttle linkage switch, etc. There is a diagnostic mode accessible on your bike, I would recommend obtaining a FSM and digging in for yourself.
I’ll see what info the dealer provides once I get the bike back tomorrow. But the dealer did say that they checked the switches.
 

thughes317

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I’ll see what info the dealer provides once I get the bike back tomorrow. But the dealer did say that they checked the switches.
I had a random issue with mine, finally isolated to the rear brake switch.......but when you tested the switch it would only misbehave once every 25-50 cycles. I discovered this using the onboard diagnostics and some dumb luck, had I only tested the switch for a few cycles (as a dealer tech may be apt to do) I would have declared it "OK" and moved on. Good luck with yours.
 

Wheelin

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I had a random issue with mine, finally isolated to the rear brake switch.......but when you tested the switch it would only misbehave once every 25-50 cycles. I discovered this using the onboard diagnostics and some dumb luck, had I only tested the switch for a few cycles (as a dealer tech may be apt to do) I would have declared it "OK" and moved on. Good luck with yours.
my cruise will reliably malfunction above 70 degrees. How's that for weird? :eek:

I don't know how to isolate the various switches, so any advice there is greatly appreciated. I'm not a mechanic, by the way, so feel free to talk to me like I'm a 6th grader. (My wife does all of the time for other things.) I have a 2016 anniversary edition, so I can likely access the onboard diagnostic, as well.
 

Wheelin

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Are they going to guarantee that the new ECU fixes the problem or are you stuck with it even though it doesn't work?
Good question. I'll ask them that tomorrow. I'm balking at that price tag, though. If I can't solve the problem, I'd probably get a used one somewhere, if the ECU is indeed the problem.
 

thughes317

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my cruise will reliably malfunction above 70 degrees. How's that for weird? :eek:

I don't know how to isolate the various switches, so any advice there is greatly appreciated. I'm not a mechanic, by the way, so feel free to talk to me like I'm a 6th grader. (My wife does all of the time for other things.) I have a 2016 anniversary edition, so I can likely access the onboard diagnostic, as well.
Maybe in colder temps the grease (or lack thereof) on the rear brake lever pivot is gumming up and not allowing the pedal to return fully (grasping at straws here)? The brake pedal pivot needs regular greasing just like the shift lever pivot does.

If you want to go down the rabbit hole:

Regarding diagnostics and switch testing.....(credit member gv550)

To enter diag and check for codes:

Kickstand down
Transmission in 1st
Kill switch STOP
Press and hold TCS and RESET at the same time
Turn key ON
Continue to press and hold TCS and RESET until SELECT/ECU appears on
the display
Press and hold TCS and RESET again until DIAG appears
Press and hold TCS and RESET again until 1/14 appears
Press TCS until 61/xx appears. xx is the fault code, if there is more
than one they will appear in sequence
Press TCS until 62/xx appears. xx is the number of stored codes. To
clear all codes flip kill switch to RUN then STOP
Turn key OFF to exit diagnostics


To test switches:

Go into diagnostics again and toggle (TCS) up to step 20/xx. xx should
be OFF, shift to neutral and xx should be ON. Shift back to 1st.
Go to step 80/xx, xx should be OFF, press RES+ and xx should be ON.
Go to step 81/xx, xx should be OFF, press SET- and xx should be ON.
Go to step 82/xx, xx should be OFF, pull the front brake lever and xx
should be ON.
Stay on step 82/xx, xx should be OFF, press the rear brake pedal and xx
should be ON.
Stay on step 82/xx, xx should be OFF, pull the clutch lever and xx
should be ON.
Stay on step 82/xx, xx should be OFF, turn the throttle backwards and xx
should be ON.
Go to step 83/xx, xx should be OFF, pull the front brake lever and xx
should be ON.
Stay on step 83/xx, xx should be OFF, press the rear brake pedal and xx
should be ON.
Step 82 tests the cruise cancel switches, step 83 tests the brake light
switches.
 

jrusell

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Start by isolating one item at a time and then going for a ride.
If the front brake switch was replaced I would leave that for later and start with the rear brake.

The rear brake switch is mounted on the frame inboard of the rear brake pedal. You would think a dealer would be smart and start with simple things like the electrical connections, but do not assume anything and check everything is connected properly.
Then Look at the inside of the brake pedal and you can see where it attaches. Disconnect the switch from the pedal where it attaches to the pedal. Doing this will isolate the rear switch so when you operate the rear brake no brake signal will be sent to the computer and the cruise will not be disabled
Go for a ride and see if the cruise starts to work normally of do you have the same problem? If the cruise starts functioning properly you most likely have a rear pedal that is not returning fully and the computer thinks you are pushing on the pedal. remove the brake pedal, clean and grease the pivot.

If you have ever adjusted the rear pedal height for you must also adjust the brake pedal switch at the same time. Maybe this was done and you simply forgot to adjust the switch height?

Personally I think it is highly unlikely the bike needs an ECU. ECU failure is very rare. Parts changer mechanic who is too lazy or stupid to diagnose properly.
 

OldRider

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Good question. I'll ask them that tomorrow. I'm balking at that price tag, though. If I can't solve the problem, I'd probably get a used one somewhere, if the ECU is indeed the problem.
What you don't want to happen is they install the new ECU and when that doesn't fix the problem, they clean/adjust/fix the rear brake light switch, pat you on the back and charge you for the ECU. My money says the problem isn't the ECU.
 

jbrown

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Novato, CA
Just to address your question about a reflash fixing a potential ECU problem, it wouldn't. Any ECU problem related to cruise control would be an input/output circuit problem, and a flash just replaces the software. You can't fix a bad transistor or IC with new software.
 

Wheelin

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OK gang, I got the bike back and will certainly do all the things recommended above with regards to onboard diagnostic. Just as an FYI, they use the Yamaha diagnostic tool as opposed to the onboard diagnostic, and from what I can tell, it appears that they have cleared the error codes, if I’m understanding thughes317 info correctly (ie for 61 code, there was only “00”).
Here are the codes that the mechanic found with the Yamaha Diagnostic Tool:

195 Side Stand switch
50 ECU internal malfunction
90 Cruise control cancel switch.

additional comments from mechanic: “made sure all deactivating switches are connected. ECU is also properly connected. Per Yamaha code 50 requires the replacement of ECU”

I did the other checks from thughes317 and at step 82, the indicator was constantly at on and nothing I did could change the “on” status. Later, I checked step 82 again and this time, everything worked as expected.

I checked the other steps and they all functioned as expected. Are we on to anything regarding Step 82 and the cruise cancel switches?
 
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Wheelin

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Are they going to guarantee that the new ECU fixes the problem or are you stuck with it even though it doesn't work?
they said that they wouldn’t have me pay if the ECU doesn’t solve the problem, but to OldRider’s point, they could clean up a few switches and still leave me on the hook for the ECU. (I have trust issues with dealers.)
 

RCinNC

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If you end up needing to get an ECU, there's a used one for sale on eBay right now from a 2014 Super Tenere. The 2014 and 2016 ECU have the same part number (2BS-8591A-30-00). It's listed for $399.99.
 

Wheelin

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If you end up needing to get an ECU, there's a used one for sale on eBay right now from a 2014 Super Tenere. The 2014 and 2016 ECU have the same part number (2BS-8591A-30-00). It's listed for $399.99.
thanks, I saw that part earlier as well. Given the rarity of ECU failure as posited by the forum members, I may have a lot of switch checking ahead of me, though I’m sure it’ll be a chore.
 

RCinNC

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Yeah, I'd definitely rule out any other possibilities before I sprung for an ECU, even a used one. On the plus side, I doubt that an ECU for a Super Tenere is a high demand item, so it may linger on eBay for a bit in case you need it.
 
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