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Engine Fault code 20

61K views 81 replies 25 participants last post by  tekker 
#1 ·
I get this code every now and the and it is sporadic. The code is for the atmospheric pressure sensor or the air pressure sensor voltage is different. I thought the battery might not be fully charged as I only track this bike and from what I have read the R1 is not battery friendly. Put a new Shorai in an code still is there. Dealer is getting new sensors so maybe one is actually bad. Anyone have thoughts or have had this code.
 
#3 ·
I replaced the air intake pressure sensor and it seems to be ok know. Keeping my fingers crossed. I am going to have the dealer order another sensor as it is the same sensor as the atmospheric pressure sensor. I also checked for pinched hoses and other things. Hopefully that fixed the problem.
 
#5 ·
I got the code 20. I removed the air box and cleaned both censors (intake n throttle housing). Code cleared but came back on.

Checked wire looms n hoses. Seems good. So I ordered two new ones. Hope that resolves it. I will update i a few weeks.

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#6 ·
UPDATE:

I changed the sensor in the airbox. A buddy who is a mechanic told me most sensors that he has replaced are in the airbox only which has fixed the problem. He suggested just try that one first.

So I played the odds he told me. Replaced the airbox one only. Started up, code still showing after warm up. Said the Eff word and turned off bike.

Restarted a few min later, code is gone!! Turned off. Few minutes re started, code still off and remained off for test ride around the block.

I will keep other sensor as a spare. Here is a photo of how they look installed for reference. They have green tags on them which is oem.


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#7 ·
Hey all. I have recently been dealing with the same issue and was hoping there would be more insight on this issue. I have had an intermittent fault code 20. I've replaced both of the sensors and it still shows the code after a test ride. Unfortunately, this disables the Launch Control capabilities. Does anyone have any other ideas as to what could be causing the code? And does anyone know if there is a way to bypass the code to get Launch Control back online? Thanks!!!
 
#9 ·
My error 19 and 20 experiences have all been with my ignition (rusted contacts from riding in the rain or being parked for a long time in humid weather) or multifunction relay on its way out.

Troubleshoot or replace both if you can.

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#10 ·
I've got code 20 as well.

Diagnostic mode is showing 2 kPa delta in pressure between the sensors with the bike not running. Can anyone (who doesn't have engine code posted) tell me how close their atmospheric and intake pressure readings are with the bike not running (Diag codes 02 and 03)? I realize they should be dead on in theory, just wondering how much tolerance these sensors have.

Thanks!
 
#11 · (Edited)
*EDIT: I came to the wrong conclusion in this post - real issue turned out to be flaky crimped connection in main harness - see post #30 in this thread for the actual remedy to my intermittent issue and my flow chart for discriminating between sensor, ECU, and harness issues driving engine code 20. *

For those you who have replaced a sensor and are still getting the code, here's what happened in my case and how I was able to fix it:

In diagnostic mode, both sensors (atmospheric and intake) were showing below the real atmospheric pressure (1-3 kPa). I replaced the intake sensor with a brand new one because the intake pressure was farther off from real value than atmospheric sensor. Much to my dismay, the new intake sensor was still showing the same erroneous value in diagnostic mode as the old sensor...

This had me worried that the ECU input circuit was damaged - so just for giggles I swapped the connectors on the sensors to see if the errant value followed the connector (i.e. intake sensor hooked to atmospheric connector and vice versa) - and after swapping the connectors back to being connected to their proper sensors, both pressure values lined up perfectly with the real atmospheric pressure! It has been fine ever since.

My theory is that something about swapping sensor connections triggered the ecu software to re-calibrate itself for the sensors.

Hope this helps if anyone else is baffled about still getting this error code after replacing sensors.
 
#17 ·
For those you who have replaced a sensor and are still getting the code, here's what happened in my case and how I was able to fix it:

In diagnostic mode, both sensors (atmospheric and intake) were showing below the real atmospheric pressure (1-3 kPa). I replaced the intake sensor with a brand new one because the intake pressure was farther off from real value than atmospheric sensor. Much to my dismay, the new intake sensor was still showing the same erroneous value in diagnostic mode as the old sensor...

This had me worried that the ECU input circuit was damaged - so just for giggles I swapped the connectors on the sensors to see if the errant value followed the connector (i.e. intake sensor hooked to atmospheric connector and vice versa) - and after swapping the connectors back to being connected to their proper sensors, both pressure values lined up perfectly with the real atmospheric pressure! It has been fine ever since.

My theory is that something about swapping sensor connections triggered the ecu software to re-calibrate itself for the sensors.

Hope this helps if anyone else is baffled about still getting this error code after replacing sensors.
What model is your bike? Have run into the same problem after installing the dual FTecu qs/autoblip on my -15 r1m. ? All rider aids are locked down, until i can get rid of the error code, and the bike is currently a killing machine without them..
 
#13 ·
I hot-swapped the sensors (left the display in diag 02 / 03 to watch values as I plugged/unplugged sensors).

After the issue was resolved, I tried the old intake sensor on the atmospheric connector just to see if its pressure output would now match the new intake sensor (checking to see if the issue actually had nothing to do with old intake sensor), but it didn't. Closer than before the whole connector swapping process, but still had a 1 kPa delta from the new intake sensor, so I kept the old atmospheric sensor in the bike.

It seems like my case was a combination of marginal intake sensor + ECU needing to re-calibrate to new sensor?
 
#15 ·
I replaced both sensors and the code went away when I turned the ignition on. I started the bike let it warm up and the code came back. I traced the wires and found no kinks, loose connections, corrosion, and the ecu plug was tight. The code talked about voltage which got me thinking about the battery, I have a Shorai and since this is a track only bike that is not started everyday I put the charger on the battery for an hour turned the key and no code. Just wondering if a battery that is not fully charged could throw the voltage off.
 
#16 ·
Yes I have the Shorai battery as well and my bike is also track only. I only get the code when my bike gets hot, once I start rolling the code goes away then the engine light stays on. I put the bike in neutral shut it on and off while the bike was still rolling and it goes away. Weird. Gonna change my harness and see what happens...
 
#18 · (Edited)
Update:

Code20 went away by itself for some days, and came backs suddenly.
This time it came when stopping for some fuel. Then i just flipped the ignition key on/off. and the code was gone! ?


Later same day I had a power outage like stated in this tread, were the bike just shut off!
I have no clue if its another problem, or it has something to do with this code20, but I think its worth to mention. (happend twice this summer)

.


Went to do the diag test as nhenry did , and here are mine results :

Diag 02 shows 98 clear dry weather outside measured@15 degrees Celsius inside garage
Diag 03 shows 96 clear dry weather outside measured @15 degrees Celsiusinside garage

So delta 2kpa difference. I have no idea of thats much, but as stated before, shouldt theese two in teory be equal ?

Afterwards I warmed up the bike, and did another Diag test, and they showed the same results as with cold engine.




Orderd multirelay and air pressure sensor to start with.

Here are the Part numbers if someone need :

1WS-82380-00-00 SENSOR, PRESSURE (Yamaha) $90.49
1​
$90.49​
2CR-14451-00-00 ELEMENT, AIRFILTER (Yamaha) $40.78
1​
$40.78​
5VK-81950-30-00 RELAY ASSY (Yamaha) $34.94
1​
$34.94​


I will also try hotswapping the sensors 1st as nhenry suggested



Regarding the power outage I will try a reflash of the bike (Some say it could be a bad ecu block that didnt get flashed ?)
I dont have a Superbikeunlimited flash on mine, since i live in Norway, but it would be really interesting to hear their findings on the problem. :unsure:
Might be that the same problem layes within the standard FlashTune maps. Im running the unrestricted EU 15 R1 map.




If anyone has anything that might help, or found the solution, please post it ! :)
 
#20 ·
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
 

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#21 · (Edited)
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" ? ?
 
#22 ·
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.
 
#24 ·
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.
 
#27 · (Edited)
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.
 
#29 ·
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.
 
#28 ·
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.
 
#30 ·
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.
 

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