Rep Power: 0

Hey I have a 2012 civic. I randomly get a check emission system, and transmission error popup on my car and it goes away and come back for a long time now I never had any problems with it though and it would go away so I never thought anything of it. Yesterday I got that popup and the drive gear was flashing green. My car would not change gears once I hit 60mph (maybe 3rd or 4th gear I am not too sure) The engine rpm was around 3500 and would not drop down unless I slowed down. Drive to the auto parts store and plugged it in and P0843 code popped up and they told me to take it to a dealer to run diagnostics and get it fixed. I already know that bill is going to be pretty high, so I am determined to do it my self. Im looking on autozone site searching "Transmission Oil Pressure Switch" and it is showing 4 different sensors. Would you be able to help me out and let me know which one? (you need to filter the sensors to fit a 2012 honda civic LX) Thank you! Also, I am not sure of the exact location of this sensor.. If this has already been posted somewhere please let me know.

 
Rep Power: 513

What are the 3rd-5th digits of your VIN? Is it FA1 or FB2? There's some grey area between 8th and 9th gen civics for 2012. I think in NA the official start of the 9thgen was 2012, but I'm not 100% certain. Those 2 gens kinda blurred together in my head. The engine and tranny are more or less the same

If it's FA1 (chassis code for 8th gen non-si sedan), this video should help you out. If it's FB2 (chassis code for 9th gen non-si sedan), it should be similar, but part numbers will likely be different.

 
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Hey, it is FB2. I picked up a sensor from autozone, part # PS800 and installed it. The popup error went away and when I plugged it in at Oriellys on the scanner it was still showing the code, even though it wasnt showing on my car. I disconnected the negative on my battery for a couple minutes and put it back on to clear the code since they wont do it for me there. So far car been driving fine and no more popups.

Another ongoing issue is my car has been having a problem changing gears for the past couple years or so I believe changing from 3rd to 4th gear (I think) It doesnt seem to want to change gears easily until I let my foot of the gas pedal for a second, then it changes gear and I can proceed to accelerate. Not sure why it does this. Is there another sensor I can change? Thanks

 
Rep Power: 513

If the code was stored and not illuminating the check engine light, might just be a stored code. If you don't notice any issues related to that, could probably get away with clearing it and seeing if it comes back. Those autozone sensors are really hit or miss (predominantly miss, tbh), so the duralast sensor might be a bandaid for now.

are you still seeing the shift issues after swapping the sensor?

 
Rep Power: 0

Yes I still have those issues. It happens literally every time. I just got used to driving like that and release my foot from the gas for a second till it shifts, and the RPM drop down. I can try to get a video.

 
Rep Power: 513

I'm not 100% familiar with auto tranny workings, but it sounds like a shift solenoid issue.

When's the last time you had an AT fluid change? If it's been a while (or never at all), might be worth a shot. If you haven't done it at all, depending on mileage, it may be overdue anyways.

 
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TBH Im not sure of the exact mileage. A little background of my car: I dont recall exact time as to when my car was having this shifting problem, if I had to guess at least 3 years now. My car used to drink motor oil and it actually starting shaking one day and broke down. This happened somewhere around 185k miles I think. Took it to a mechanic and he said the exhaust valves were burnt and best to just get an engine swap. It got swapped for the same engine but a 2013 model and he said they usually have about 50k miles on it. My car now has about 205k miles on it. I did buy some transmission oil to do a change when I got the new sensor, but have not changed the fluid yet. I will be doing that this week.

 
Rep Power: 513

Def keep us posted after you change the tranny fluid. Run it for about 500 miles or so with the new fluid just to make sure.

 
Rep Power: 0

I am experiencing this same issue with my automatic transmission on my Honda Civic 2012 EX-L. Mine is 9th generation, FB1.
Last week:

1. CHECK EMISSIONS SYSTEM and CHECK TRANSMISSION lights both came on
2. D flashes on the dashboard
3. Vehicle struggles to shift during acceleration, RPMs well over 3K and approaching 4K
4. P0843 fault

I changed the transmission fluid. Codes went away and normal gear shifting resumed on my car.

That lasted for a week and about 400 miles. The dash light came back. It's shifting better than last week, but still doesn't seem right.

 
Rep Power: 0

I had this exact situation on my Honda Civic EX-L 2012 with 190,000 miles and it went away after I changed the transmission fluid. Give that a try before throwing sensors at it.

 
Rep Power: 0

Fixed. Replaced Transmission fluid and had to re-clear the code one additional time.