[avisitor]

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

 

[fixingstill]

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.)

 

[avisitor]

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

 

[nitely]

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.

 

[fixingstill]

If O2 sensor does not fluctuate with changes in fuel adjustment during closed loop then that may be an issue.

I studied about the A/F sensor (lambda, wideband, whatever you call it).
When I do a quick throttle snap, the A/F sensor will respond and then stabilize.
The downstream sensor is not a A/F sensor but just a regular O2 sensor. It stays in 0.9V but it does respond to throttle snap. dropping down to 0 sharply and then sharply going back to 0.9V.
I think I need to change the downstream O2 sensor? They are supposed to be at around 0.45V??

Let the cars computer diagnose itself by driving the car. It can't do that if its turned off.

Yes, but without a license plate, I hate to be stopped by police to show them all paperwork. You never know what other trouble they might give me.
And also when the transmission is jerky, I really don't want to drive it for too long because it might damage something.
And if I were to take it to dealer to check the transmission, (my scanner has the "Resetting Auto T/A Values" and "AT adaptation mode" even I could not successfully execute them), I want a license plate on the car so that they don't question much.

Regarding your CEL-misfire after transmission swap and you changed all the plugs and coil packs; Before the transmission swap, was there a CEL or was it having a misfire already? If not, maybe a dealer reflash may have helped there.

Bought the car used from auction. Tranny was able to reverse only. After replacing the tranny and drove around, misfire code showed up. Replacing the plugs and coils fixed them (I think 2 coils were intermittently bad.)

Yes, a lot of work to revive a car that other people have given up.

I will get a downstream O2 sensor and see unless any experts here can give me some pointers.

 

[nitely]

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.

 

[fixingstill]

"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".

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.

 

[nitely]

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.

 

[GenxRS]

"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".

View attachment 445004

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.

 

[pancho19]

Feel free to disconnect your battery again and drive it for 100 miles for several days then check it after.

What did you repair needing to disconnect the battery? Do you have the CEL on?

Who told you that you need to drive a 100 miles, that's wrong each uses a drive cycle to complete the monitors. Misfire, Fuel system, & component monitors complete as soon as you start the vehicle unless there is an issue present.

 

[DIANEM]

Could be a bad gas cap. Only buy OEM.

 

[Zeng1618]

"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".

View attachment 445004

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.

Hi, buddy, do you change the O2 sensor, do you fix that problem, "fuel" monitor keeping incomplete. I had the some issue with 2017 Elantra 147K. since I found it, I drove more the 3000 mile and more than half year, the "F" monitor is still incomplete. I scanned whole system without anything wrong. 23 modules without any issue.

 

[ppvsteve]

Just wanted to provide some information on this topic as it does not seem like it was resolved.
The OP is from CA. In CA you actually do not need to have the fuel monitor completed to pass a CA smog check. It is not mentioned often because this is such a rare occurrence but the continuous monitors are ignored during a CA smog check.
See section C footnote 3 in the link below:

On-Board Diagnostic Test Reference

A summary of pass/fail standards for the On-Board Diagnostic (OBD) test portion of a Smog Check inspection and instructions for inspecting vehicles with known OBD test difficulties.

www.bar.ca.gov

So if OP would have gone and actually had his car SMOG tested he would have passed. Problem is about 90% of the inspectors do not now this because they don't read the literature so they send people away without providing them a test. So be firm and insist that they do the test . Inspectors are not in control on the OBD portion so they can't fail you if they wanted to.

If they won't perform a test I suggest filing a complaint with the State BAR. It is inspectors jobs to test cars as they are presented not save people from a fail.

File a Complaint

The Bureau of Automotive Repair’s Online Complaint Form...

www.dca.ca.gov

Hope OP got it figured out!!