Yamaha R1 Forum: YZF-R1 Forums banner
21 - 40 of 66 Posts

·
Premium Member
Joined
·
262 Posts
I faced the same issue with error code 20.... i replaced the 2 air pressure sensors with new one and the error code went off. But, after a day or 2 the error code came back again. Finally i disconnected the short hose from the sensor to the inlet airbox as shown in the attached photo and the error code disappeared for good since a month ago till today ( i did not see the error code display again). As whether it will affect anything other things or the performance of the bike..... NOPE.... it does not.... everything/power is the same as b4. My one cent worth of thought.... Cheers and have a nice weekend
I guess the code dissappared since both sensors are now meassuring the same pressure? The whole idea with two sensors is to have a reading inside the airbox right, and compare it to the external pressure? ?

Here is just a tought. Would a dirty air filter have any inpact on the readings from the "airintake box sensor" ? ?
 

·
Going Gorilla
Joined
·
65 Posts
Hey, after some trial and error, my Unpredictable and intermittent fault code 20 was cured. However, after doing all of the recommended sensor replacements and ECU reflash and a thorough wiring check, it came down to purchasing a new (used on eBay) ECU. Loaded my FlashTune into the new one and that was the end of the fault code 20. Good luck.
 

·
Premium Member
Joined
·
262 Posts
Hey, after some trial and error, my Unpredictable and intermittent fault code 20 was cured. However, after doing all of the recommended sensor replacements and ECU reflash and a thorough wiring check, it came down to purchasing a new (used on eBay) ECU. Loaded my FlashTune into the new one and that was the end of the fault code 20. Good luck.
Damn.. Sounds expencive. How long have you been using the new ECU without any errors?
 

·
Going Gorilla
Joined
·
65 Posts
Yeah, not cheap, but as a biproduct of the fault being active, it was disabling my launch control. Not ideal for a racer. You may have to bite the bullet and test an ECU swap. Best if you have a friend with an R1 that would let you test it.
 

·
Going Gorilla
Joined
·
65 Posts
Oh, and to answer your question, I used it successfully for two trackdays and a race weekend. Not even one hiccup. (Knock on wood)
 

·
Registered
Joined
·
14 Posts
I guess the code dissappared since both sensors are now meassuring the same pressure? The whole idea with two sensors is to have a reading inside the airbox right, and compare it to the external pressure? ?

Here is just a tought. Would a dirty air filter have any inpact on the readings from the "airintake box sensor" ? ?
My air filter was clean when the error code display persisted.... but since FTECU can reflash and disable the air pressure sensor (since the aps r use just for measuring of air pressure), which i though it will not make much or any different since i disconnected the hose thus i just let it be disconnected as long as no more error code 20 being display and does not affect the performance of the bike
 

·
Registered
Joined
·
19 Posts
EDIT: Original ECU was fine in my case. See what really fixed my intermittent issue in post #30

Issue has recurred for me. After more troubleshooting, I'm noticing that when swapping connectors on one sensor, the Intake connector input to the ECU always reads 1 kPa lower than the atmospheric input connector - which leads me to believe that something is wrong with the ECU input circuit :(

Going to scavenge an ECU off of ebay, I'll let you guys know if that clears the issue up in my case.
 

·
Registered
Joined
·
3 Posts
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.
 

·
Registered
Joined
·
3 Posts
Issue has recurred for me. After more troubleshooting, I'm noticing that when swapping connectors on one sensor, the Intake connector input to the ECU always reads 1 kPa lower than the atmospheric input connector - which leads me to believe that something is wrong with the ECU input circuit :(

Going to scavenge an ECU off of ebay, I'll let you guys know if that clears the issue up in my case.
I solved the issue. Don't waste your money on an ECU.
 

·
Registered
Joined
·
19 Posts
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.
 

Attachments

·
Registered
Joined
·
3 Posts
Hell yeah!!! That picture of the wiring harness is beautiful. Good work @nhenry. If only Yamaha had soldered those blues together or joined them with a legit connector! Even a little bit of oxidation on those low voltage connections can screw up important ECU readings. I hope everyone with fault 20 sees this thread and your contribution @nhenry. :D(y) My solution above is simply a bypass of that unseen shitty crimped wire junction. I'm glad to know that the 5 volt reference difference is not because of the ECU, but because of wiring harness. Yamaha needs to not cut corners on their wiring harness! Hopefully they have stepped it up since then! Again, fantastic work.
 

·
Premium Member
Joined
·
262 Posts
Hi! @nhenry
Trying to fix the bad wiering now. Quick question. Is it behind this heat crimp sleeve? Did you just removed the oem connection crimp, and soldered it back together?
Thanks for any response!

Already tryed swapping sensors, and replaced one with a new one (even if i think the old was ok) Still randomly gets code 20 with some deltaP difference on the sensors.
1012427
 

·
Registered
Joined
·
19 Posts
Hi! @nhenry
Trying to fix the bad wiering now. Quick question. Is it behind this heat crimp sleeve? Did you just removed the oem connection crimp, and soldered it back together?
Thanks for any response!

Already tryed swapping sensors, and replaced one with a new one (even if i think the old was ok) Still randomly gets code 20 with some deltaP difference on the sensors. View attachment 1012427
That looks like about where the bad factory splice was (you should be able to see the blue sensor power wires coming out the right side of the heatshrink to be sure).

I cut the factory splice out, replaced with a short piece of wire, butt spliced (with 2 uninsulated butt connectors), and soldered all splice connections. Finished with heatshrink overtop of the connections, and re-wrapped the whole bundle with electrical tape.

Soldering butt splices after crimping may be overkill, but I wanted the connections to be bulletproof. She hasn't given me any trouble since.
 

·
Premium Member
Joined
·
262 Posts
That looks like about where the bad factory splice was (you should be able to see the blue sensor power wires coming out the right side of the heatshrink to be sure).

I cut the factory splice out, replaced with a short piece of wire, butt spliced (with 2 uninsulated butt connectors), and soldered all splice connections. Finished with heatshrink overtop of the connections, and re-wrapped the whole bundle with electrical tape.

Soldering butt splices after crimping may be overkill, but I wanted the connections to be bulletproof. She hasn't given me any trouble since.
Ok, thanks a bunch man!! 😊
There is two blue wires at the bottom of the heat crimp sleeve, so i guess this is the one then. Really painful to get enough wiering here. Did you have to remove the airbox, and funnels, or was you able to do it all from the side? (as pictured)?
 

·
Registered
Joined
·
19 Posts
Ok, thanks a bunch man!! 😊
There is two blue wires at the bottom of the heat crimp sleeve, so i guess this is the one then. Really painful to get enough wiering here. Did you have to remove the airbox, and funnels, or was you able to do it all from the side? (as pictured)?
I actually wound up removing the whole harness and doing the crimping / soldering with harness off the bike. There might be a quicker/easier way, as pulling and reinstalling the harness is not a quick process, but I couldn't fit my crimpers in that space with harness installed on bike.

If you pull the harness, I recommend writing down and counting connections as you disconnect. There are a lot, and it would be easy to forget one somewhere on the bike.
 

·
Premium Member
Joined
·
262 Posts
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! 😎🤘
 

·
Going Gorilla
Joined
·
65 Posts
Just updating my bike's status on this fault code. My last post was post #22 and #25. It did come back in the season opener this year. Also, there seems to be a flickering of my dash display while riding. Not the most comfortable feeling knowing my electronics were getting wonky. My mechanic has noticed that the battery (OEM) wasn't putting out enough power to the dash and thus could be causing the fault code 20 to come back intermittently. Replaced it with a high-quality aftermarket battery. Will update when we're finally back on track. Thanks everyone for continuing to contribute to this.
 

·
Premium Member
Joined
·
262 Posts
Just updating my bike's status on this fault code. My last post was post #22 and #25. It did come back in the season opener this year. Also, there seems to be a flickering of my dash display while riding. Not the most comfortable feeling knowing my electronics were getting wonky. My mechanic has noticed that the battery (OEM) wasn't putting out enough power to the dash and thus could be causing the fault code 20 to come back intermittently. Replaced it with a high-quality aftermarket battery. Will update when we're finally back on track. Thanks everyone for continuing to contribute to this.
Have you followed nhenrys steps in post #30 ? I redone the OEM bad splice (picture in post #33) and rode about 500km after that. No error yet. Code 20 is triggered when the atmospheric and intake pressure sensors values dieffer with about 2-3kpa.
You can easley check this in diag mode, #3 and #4 i think. Values should be somewere in the ballpark off 95-103 Kpa, depending on weather and height were you live.
 

·
Going Gorilla
Joined
·
65 Posts
Have you followed nhenrys steps in post #30 ? I redone the OEM bad splice (picture in post #33) and rode about 500km after that. No error yet. Code 20 is triggered when the atmospheric and intake pressure sensors values dieffer with about 2-3kpa.
You can easley check this in diag mode, #3 and #4 i think. Values should be somewere in the ballpark off 95-103 Kpa, depending on weather and height were you live.
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?
 
21 - 40 of 66 Posts
Top