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Fuel System in Emission Readiness Still incomplete.

23K views 32 replies 9 participants last post by  ppvsteve 
#1 ·
Got a 2015 Elantra SE (for US market) here that I could never get the FUEL system completed.
Need it complete to go to smog check.
Usually Fuel system is the first to get completed. Now even the Evap is complete but it still isn't.
I have disconnected battery when I was doing some repair. Since then I have touched nothing.
This is strange. Just wanted to see if this is a known problem, or I should disconnect battery or clear code (even there is no code) to restart the emission cycle. Or I heard something about the ECU reflash, which is nothing to do with this, right?

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#3 ·
Right. I have been to a few of these rodeos. Usually fuel monitor is the first to complete, then the cat and O2 are usually taking their time. This is the first I have seen that the fuel monitor doesn't get completed for this long. Maybe something got stuck... or firmware problem...
 
#7 ·
You don't say where you are.
In New York State, it is possible to pass inspection if the check engine light is off and only one readiness monitor is off.
Don't know about your state.
Fuel system is usually one of the first to set.
Find out the parameters and see if you have met them.

Good luck
 
#9 ·
Hmmmm... "O2 sensor in closed loop." That means me wonder.
I just did more scanning. There is no DTC and everything runs fine. The fuel system is in closed loop after warming up. Still I have a FUEL MONITOR incomplete.
I totally agree it should be the first to set.
I am in CA. We need all but Evap to complete to have a chance to pass smog.

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The first sensor output is B1S1. 2nd sensor output is B1S2.
I thought the B1S1 would go up and down like a sine wave even when RPM is steady. Anyone seeing problem here that B1S1 is not reading right?
Man, I need Pine Hollow Diagnostic or Scanner Danner.
 
#13 ·
Yeap, it is a wide band (according to Amazon item description). It has 5 wires. It is supposed to measure current, not voltage.
I was looking at the OBD PIDs. I need to see the vehicle specific PID (later today) but it does not look like the cause of my problem. Maybe I will keep on driving and see.
So much to learn with modern engine management.
 
#17 · (Edited)
Try reseating the O2 sensor connection and any other sensor relating to fuel that you disconnected when you did the tranny swap. Make sure you hear it all click. Wow, new tranny already on a 2015? How many miles when it died? Did the same job a year ago on my '99 odyssey @226K. Got a reman from ebay with 2 year warranty. Dyno tested. So far so good.

Its possible you may have accidentally pulled the wiring a little too hard damaging it. Or its just coincidental that the O2 sensor is failing.
 
#18 ·
2015 with 135k. Bought it cheap because transmission only did reverse no forward.
After transmission is replaced, adaptation reset (still need to do relearn thou), car runs fine. Then, engine misfired. Replaced all ignition coils and spark plugs. So far so good.
Anyway, I double-checked all connections. All good. There is no code either. So, just keep on driving I guess. I will report back.
 
#21 ·
Scan ECU. Read any codes.
If there are codes then this will prevent monitors from completing.
Then watch data PIDs on short and long term fuel trim
If the numbers are near zero then ideal
If not then must see reason why
Sometimes if O2 sensors not working properly then monitors won't set
 
#22 ·
Did all that.
No codes (using Maxisys MS906BT). Long and short term fuel trims are zero, or near zero. I also looked into the upstream O2 sensor and determined it is a wideband and does not fluctuate like a regular one.
I can hook up the car to 12V charger, keep ignition on, hook up the scanner and connect it to wifi, and run teamviewer quick support on it so that anyone who is good at troubleshooting and reading these PIDs to give it a shot where it goes wrong (and I will start the engine if there is a need). Text me at 510-441-7444 if you can help. Thanks.
(Should I use the OBD protocol or vehicle specific protocol to look at the PID? That would be my first question.)
 
#23 ·
Did all that.
No codes (using Maxisys MS906BT). Long and short term fuel trims are zero, or near zero. I also looked into the upstream O2 sensor and determined it is a wideband and does not fluctuate like a regular one.
Fuel system monitor is a continuous test.
It monitors control of fuel adjustments
If O2 sensor does not fluctuate with changes in fuel adjustment during closed loop then that may be an issue.
Check the wiring to and from the O2 sensors, connectors
 
#24 · (Edited)
Instead of playing with your gadget, drive your car. If there is a problem, usually after driving so many miles - from a few hundred to a few thousands or so - it will come out and your CEL will turn on. Let the cars computer diagnose itself by driving the car. It can't do that if its turned off.

Another thing, some newer vehicles sometimes requires the dealer to reflash the cars computer when putting a different transmission.

Regarding your CEL-misfire after tranny swap and you changed all the plugs and coil packs; Before the tranny swap, was there a CEL or was it having a misfire already? If not, maybe a dealer reflash may have helped there.
 
#26 ·
If your newly installed used tranny is jerky now, either it has an internal issue right at the get go or you need the dealer to reflash the cars computer to run right. I would call a couple of dealers and ask them if a reflash is required for replacement transmission so the car will run properly. I would have done this research way before buying a used tranny. Anyway, they should be able to tell you. Compare their answers and cost for it. If it is required, explain your situation and bring it in, if you have the paper work for the car, should be a non issue. You are trying to register it after all. Get it towed in if you don't want to drive it. How bad is it running now? You will never fix that car if that dealer reflash is required. And if its a bad used tranny, then thats another layer to your dilemma. Good luck.
 
#27 ·
"dealer reflash"... I changed out the transmission but I did not change out the TCM (transmission control module). I do understand there is some electronic on the valve body inside the transmission. I also understood that I need to do "resetting values" and "AT adaptation mode".

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Note. Resetting is easy. Just clicks. "Adaptation Mode" is hard... It needs driving around while keeping the throttle at 10 to 20%. I tried hard and it failed even I kept it at 10-20%.
Everytime I reset the values, it runs smooth for a few miles before the shifting from 1 to 2 and 2 to 3 becomes jerky. I concluded it is not mechanical issue.

When you say "dealer reflash", what do they do? Reflashing some electronic inside the valve body?

Still want to get the smog passed first before spending more $ with the stealership.
 
#29 ·
"dealer reflash"... I changed out the transmission but I did not change out the TCM (transmission control module). I do understand there is some electronic on the valve body inside the transmission. I also understood that I need to do "resetting values" and "AT adaptation mode".

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Note. Resetting is easy. Just clicks. "Adaptation Mode" is hard... It needs driving around while keeping the throttle at 10 to 20%. I tried hard and it failed even I kept it at 10-20%.
Everytime I reset the values, it runs smooth for a few miles before the shifting from 1 to 2 and 2 to 3 becomes jerky. I concluded it is not mechanical issue.

When you say "dealer reflash", what do they do? Reflashing some electronic inside the valve body?

Still want to get the smog passed first before spending more $ with the stealership.
What was the result of your issue? Did driving more clear the code? I have a 2014 Sonata with the same issue. Replaced the battery and so far drove about 200 miles and code has not cleared while others have. Thank you.
 
#28 · (Edited)
For the last time give them a call.

Example, my 99 odyssey did not need dealer ECU reprogramming when I replaced the transmission with a reman. It run great as soon as I fired it up. However, my 04 murano, should the the CVT fail and I choose to replace it, will require a trip to the dealer for it to run properly. Its basically programming your ECU to talk to the new CVT so that it will run properly. The ECU will sync with the TCM and push the new CVT profile into the TCM. Very few shops have the expensive equipment to perform this, what more a regular Joe like me. I suspect this maybe your case since this is a 2015. More ECU dependent. It might also correct your pending fuel system readiness.
 
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