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Definitely the next steps if problem comes up again...which I have a sneaky suspicion it will.
So aside from the fault code 20 nullifying launch control, should there be any concern that it is nullifying any of the other rider assists? What are your guys’s thoughts on this?
If I remember correctly, you also lose lift control, which will be a nasty surprise in 1st gear if you're assuming it's enabled with a big handful of throttle. I actually added a check of rider aid status (on dash) to my pre-ride mental checklist for that very reason - don't want to be this guy:

I turned lift control off for giggles the other day - the rate at which the front jumps up with even moderate throttle in 1st gear power band is absolutely wild. On a first gear 60 roll, anywhere near 100% throttle with no lift control would throw you off the bike before you had any idea what happened.

Beyond the rider aid inhibits, you'll likely lose power as the ECU can't accurately measure intake airflow (calculated via difference between intake pressure and atmospheric pressure), and thus can't deliver proper fuel mixture.
 

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Going Gorilla
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It’s incredible to me that Yamaha hasn’t at least acknowledged this issue and advised what the symptoms of it would be.
 

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If I designed it, there would be a warning message flashing until acknowledgement if lift control, tc, or abs is automatically disabled due to fault. That's how failure alerting works in the glass cockpit aviation world, as a crew not noticing an abnormal system state can be disastrous.

Since we don't have that luxury, a mental pre-ride checklist item for rider aid state is important.
 

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Beastmode!
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From my experience all the electronics stopped working LC, TC, SC everything and this during a race, even your brake markers make a difference. It only happens when my bike gets hot so I made sure it was always in the shade and didn't have an issue, it's not the correct fix for it.
 

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Beastmode!
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I have SOLVED this issue. Check the voltage being sent to the inlet pressure sensor and to the atmospheric pressure sensor. If they aren't exactly the same, you will have fault code 20. The sensors require a "5 volt reference". The value itself doesn't matter much, but they must both be equal. To see if this is your issue, check the voltage of the blue wire of each sensor. I believe that either the distance from the ECU or the ECU itself is sending the wrong voltages to the sensors. I measured the voltage being sent to the inlet pressure sensor and the atmospheric sensor. The voltages were 4.93 volts and 4.80 volts. This means that the inputs from the ECU are off. I have made a video to show you what to do to send the proper voltage to the sensors. The other option is to replace your ECU and hope that the proper 5 volt references are sent to the sensors. Here is what you need to do to get rid of Fault Code 20:
I rode the bike afterward and had no fault codes, hiccups, or issues.
What year is your bike?
 

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Beastmode!
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Can confirm now that it was the right heatcrimp on my picture. 3 blue wires on top and 2 comming in from the bottom.
I was able to solder it on the spot, but be warned. It was kinda brainsurgery job, and i took my time doing it, but it was doable 😎

Spliced and soldered a long blue 1.5mm2 wire with the top 3, then put heatcrimp and finished that up first. Then cut the new wire to a ok lenght i could work with, but a heatcrimp sleeve over it, and spliced&soldered the it with bottom 2 wires, and isolated it with the heatcrimp. Then finished everything up with vulcantape. Both sensors showing 98kpa at the moment. Going for 2 hour test run soon, and will report back afterwards! 🙂

Again, thanks to everyone that keeps this forum alive, and special thanks to @nhenry for his job on this case and quick response here! 😎🤘
Wouldn't happen to have any pics would you?
 

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Beastmode!
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Alright gents, my issue is finally resolved. ECU was not at fault in my case, and the hot-swap fixing of issue I described in earlier post was just a coincidence with the bad harness connection randomly floating to within tolerance. See my attached custom flow chart for troubleshooting engine code 20 on 2015 r1 - the OEM shop manual troubleshooting process makes some faulty assumptions.

After tons of resistance measurements, I narrowed my remaining intermittent issue down the the solid blue wire ("L" color code in 2015 OEM shop manual wiring diagrams) crimped junction in the main harness - somehow the junction connection to the intake sensor power wire was higher resistance than it should be (was randomly floating around between a few ohms and ~100 ohms as measured between ECU side of junction and Intake sensor connector), which would cause the voltage at the sensor to be intermittently lower as duttonwebb described, and thus give an errant low pressure value as seen by ECU @ its input pin. I actually did have one sensor that was a bit off as well (see my flow chart for how that was isolated/derived). So in the end, I replaced one of the sensors, and I cut out the factory blue wire crimp and re-crimped, soldered, and added heat shrink over my crimps before wrapping the whole bundle back up with electrical tape.

My attached flow chart should help you discriminate between sensor, ECU, and harness issues for error code 20 on a 2015 R1 - no need for Yamaha's special piggy back connector to check the sensors. I would recommend performing each of the flow chart resistance measurements multiple times to ensure your connection between multimeter and connector pin is good, i.e. you're not going off of false readings.

The 2015 OEM workshop manual troubleshooting process for engine code 20 assumes that there's no harness issue at play, which is clearly a poor assumption as duttonwebb and I found.
Nice work!!
 

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Premium Member
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Update on this code 20 problem.
My problems havent occoured for over 4000km 🙂

Borh sensors show exact same Kpa after i soldered the point Nhenry suggested. 🙌👌

So i recommend everyone experiencing this problem to read this tread carefully and follow Nhenry's guide 😉
 

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I finally just handed it over to my dealer something has to give
Hi.
Did you read from post #30 and out?
Nhenry:s solution had fixed my code 20 for good. Was a bad oem 3 wire solder located on the wiering harness behind the ECU/left side.

Please read post #30, #33 and look at the picture if you havent already.
It may be money out of your pocket if a dealer is charging you for the hour, and replacing sensors, ecu and so on! 🤐

Rs14a
 

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Can anyone add to this thread? I’m getting the intermittent code 20. Tried a different ECU and still have the issue. I believe my sensors are good because when I go into the diagnostic mode, the values change throughout the day.
I’m confused by the wire harness fix—from the picture it looks like you just wired the two blue wires together.

This thread is a few years old now—any better ideas and those that followed this thread did it solve the problem long-term?
 

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'08 r1
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Alright gents, my issue is finally resolved. ECU was not at fault in my case, and the hot-swap fixing of issue I described in earlier post was just a coincidence with the bad harness connection randomly floating to within tolerance. See my attached custom flow chart for troubleshooting engine code 20 on 2015 r1 - the OEM shop manual troubleshooting process makes some faulty assumptions.

After tons of resistance measurements, I narrowed my remaining intermittent issue down the the solid blue wire ("L" color code in 2015 OEM shop manual wiring diagrams) crimped junction in the main harness - somehow the junction connection to the intake sensor power wire was higher resistance than it should be (was randomly floating around between a few ohms and ~100 ohms as measured between ECU side of junction and Intake sensor connector), which would cause the voltage at the sensor to be intermittently lower as duttonwebb described, and thus give an errant low pressure value as seen by ECU @ its input pin. I actually did have one sensor that was a bit off as well (see my flow chart for how that was isolated/derived). So in the end, I replaced one of the sensors, and I cut out the factory blue wire crimp and re-crimped, soldered, and added heat shrink over my crimps before wrapping the whole bundle back up with electrical tape.

My attached flow chart should help you discriminate between sensor, ECU, and harness issues for error code 20 on a 2015 R1 - no need for Yamaha's special piggy back connector to check the sensors. I would recommend performing each of the flow chart resistance measurements multiple times to ensure your connection between multimeter and connector pin is good, i.e. you're not going off of false readings.

The 2015 OEM workshop manual troubleshooting process for engine code 20 assumes that there's no harness issue at play, which is clearly a poor assumption as duttonwebb and I found.
Can anyone add to this thread? I’m getting the intermittent code 20. Tried a different ECU and still have the issue. I believe my sensors are good because when I go into the diagnostic mode, the values change throughout the day.
I’m confused by the wire harness fix—from the picture it looks like you just wired the two blue wires together.

This thread is a few years old now—any better ideas and those that followed this thread did it solve the problem long-term?
The blue wires referenced in nhenry's post are in a shared block so yes. Tie them all together. They are already tied together in the block. Soldering the connection is not a bad idea. If the connection block fails, you will get some screwy readings for sure.

If you read through the thread some folks have been back to chime in that the fix is still good.
 

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Can anyone add to this thread? I’m getting the intermittent code 20. Tried a different ECU and still have the issue. I believe my sensors are good because when I go into the diagnostic mode, the values change throughout the day.
I’m confused by the wire harness fix—from the picture it looks like you just wired the two blue wires together.

This thread is a few years old now—any better ideas and those that followed this thread did it solve the problem long-term?
You need to locate and solder the 3 blue wires that are crimped together. I think i have pictures of it here in the thread, or atleast explained how I fixed it.
I Had the excact same sympthons as you, and both sensors checked out good. They should read the same in diag mode after you have soldered the 3-wire crimp. Mine has been spot on since I did the fix, and never have code 20 come back again 😊
 

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Have a close look at the pictures in nhenrys post #30 and my post #33
 

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What i did was:
1.Carefully cut open the oem headshrink.
2.Cut off the crimp.
3.Soldered slightly longer wires into to the wiering loom to make it easyer to work with.
4.Slided on two new headshrink tubes.
5. Soldered everything back together again.
6. Isolated the new soldering points with the heatshrink tubes that i previously slided into the loom.

It was abit of a patience test, as there is little room, but after i spliced in some more wire it was a doable 😊
 

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Nice! Thank you for the clarification and the update to know this was a long term fix!


Sent from my iPhone using Tapatalk
 

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Nice! Thank you for the clarification and the update to know this was a long term fix!


Sent from my iPhone using Tapatalk
Your welcome 😊
Note: I edited the post and switched Nr 3 and 4 around

It might not be neccesary to splice in longer wires, but i found it easyer that way. I suppose you could always just solder over the connection, spray it with contact sealant spray, and insulate with electical or vulcan tape.

Hope this gets you rolling again, and please chime later and let us know it worked out for you 😀

Ride safe 🤙😎
 
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