[millemal]

Check Engine, Rough Terrain/XMode, Eyesight Disabled, Lane Keeping Assistance (LKAS) Off lights all appeared on the car, removing all safety features, after filling up with gas after driving the car for about 300 miles. The lights were still on the next day when I started the car, so when we arrived at our destination I disconnected the battery and let the car sit for a few minutes. This cleared the errors and the car functioned with all safety features again.

A week later on the return trip we filled up with gas after about 300 miles and had the same issue occur. On both trips while on the highway, we were using the LKAS and adaptive cruise features before refueling. I decided to not clear the error and instead called subaru to have the dealer service check out the issue. After driving for a few days, before the service could check it out, the errors cleared themselves and everything is fine again. I called the dealer and they said without the codes they would not be able to diagnose the issue, so I should not bother bringing the car in.

Has anyone else had this issue? Very frustrating. No other issues with the car.

 

[Ruben Marin]

I would go to an auto parts store and see if they can pull the stored codes, sounds like you may have a bad gas cap or another issue in the evaporative emissions control system. Anytime a malfunction indicator light comes on the code is stored in the ecm memory.

 

[E-EC-ECU]

Couple of quick question.

1.) Did you fill the tank with the car running? I only ask because a recent thread discussed issues (engine cut off) experienced very soon after fueling the car ... while it was running! While I do not know for sure if these items were directly related to one another. Other thread Fumes, pressure change, etc??.

2.) Gas cap? Can you check the gas cap for a good seal on the cap itself, or even on the "intake port". I only mention this one because a loose gas cap will create an "emission evap control" (or something like that) issue that is simply resolved by tightening the gas cap. The problem is that the lights will NOT reset immediately. From what I understand, it takes a number (maybe 2-3) "full cycle" engine uses. I made up the term "full cycle", but essentially means that the car went from cold to operating temperature. So, simply turning the car on and off a couple times won't help. Maybe you have a gas cap that isn't making the best seal and triggers the issue, but resolves itself with back pressure from the gas tank, then occurs again later on.

One last thing. If you ever get a Check Engine Light, you can always go to Advance Auto, or Napa (or similar) and they "should" pull the code for free. No need for a dealer just to pull a CEL code. No appointment necessary. I bought an ODB2 reader and have ActiveODB to do this stuff at home, but that might not be a desire of yours.

 

[millemal]

I would go to an auto parts store and see if they can pull the stored codes, sounds like you may have a bad gas cap or another issue in the evaporative emissions control system. Anytime a malfunction indicator light comes on the code is stored in the ecm memory.

Thank you very much! We will do this next time.

 

[millemal]

Couple of quick question.

1.) Did you fill the tank with the car running? I only ask because a recent thread discussed issues (engine cut off) experienced very soon after fueling the car ... while it was running! While I do not know for sure if these items were directly related to one another. Other thread Fumes, pressure change, etc??.

2.) Gas cap? Can you check the gas cap for a good seal on the cap itself, or even on the "intake port". I only mention this one because a loose gas cap will create an "emission evap control" (or something like that) issue that is simply resolved by tightening the gas cap. The problem is that the lights will NOT reset immediately. From what I understand, it takes a number (maybe 2-3) "full cycle" engine uses. I made up the term "full cycle", but essentially means that the car went from cold to operating temperature. So, simply turning the car on and off a couple times won't help. Maybe you have a gas cap that isn't making the best seal and triggers the issue, but resolves itself with back pressure from the gas tank, then occurs again later on.

One last thing. If you ever get a Check Engine Light, you can always go to Advance Auto, or Napa (or similar) and they "should" pull the code for free. No need for a dealer just to pull a CEL code. No appointment necessary. I bought an ODB2 reader and have ActiveODB to do this stuff at home, but that might not be a desire of yours.

1. We had the car turned off while pumping. I saw that post as well but it appears we are having a different issue.

2. I tried redoing the gas cap multiple times as well as leaving the car overnight. This did not resolve the issue. But after a few days of having the code on, and doing normal restarts in the morning after off overnight, the code did clear. So you may be on to something here.

Thanks for the tip about going to a parts shop to get the code cleared. I will definitely try this next time the code comes on. If it turns out to be a gas cap, is this something I can replace?

 

[Titanrx8]

Thanks for the tip about going to a parts shop to get the code cleared. I will definitely try this next time the code comes on.

Parts shops will read codes, they won't clear them. You shouldn't clear codes since the dealer or other shops need the codes.

 

[Ruben Marin]

1. We had the car turned off while pumping. I saw that post as well but it appears we are having a different issue.

2. I tried redoing the gas cap multiple times as well as leaving the car overnight. This did not resolve the issue. But after a few days of having the code on, and doing normal restarts in the morning after off overnight, the code did clear. So you may be on to something here.

Thanks for the tip about going to a parts shop to get the code cleared. I will definitely try this next time the code comes on. If it turns out to be a gas cap, is this something I can replace?

The ecm will need to go through 2-3 drive cycles without an fault for the CEL light to turn off, it is more involved that just starting the car. A drive cycle requires certain criteria to be satisfied for the cycle to be completed. You can usually do a visual check on the gas cap seal to see if there is any deterioration of the gasket.

Parts shops will read codes, they won't clear them. You shouldn't clear codes since the dealer or other shops need the codes.

Some stores here will, depends on the person. But what I thought was curious was the service center declaring there was nothing to be done until the code comes back. I thought codes were committed to memory whether they were active or not.

 

[E-EC-ECU]

If it turns out to be a gas cap, is this something I can replace?

Absolutely: Fixed with OEM parts for only about $25.00. Fuel Tank Cap

 

[DZTex]

Same problem with my 2021 Ascent with 23K miles. Tightened gas cap but then it took 700 miles, several gas fills and numerous starts / stops for it to clear. At least the car ran fine during the time the systems were disabled. Guess I'll cancel my service appointment.

 

[valaitiska]

Check Engine, Rough Terrain/XMode, Eyesight Disabled, Lane Keeping Assistance (LKAS) Off lights all appeared on the car, removing all safety features, after filling up with gas after driving the car for about 300 miles. The lights were still on the next day when I started the car, so when we arrived at our destination I disconnected the battery and let the car sit for a few minutes. This cleared the errors and the car functioned with all safety features again.

A week later on the return trip we filled up with gas after about 300 miles and had the same issue occur. On both trips while on the highway, we were using the LKAS and adaptive cruise features before refueling. I decided to not clear the error and instead called subaru to have the dealer service check out the issue. After driving for a few days, before the service could check it out, the errors cleared themselves and everything is fine again. I called the dealer and they said without the codes they would not be able to diagnose the issue, so I should not bother bringing the car in.

Has anyone else had this issue? Very frustrating. No other issues with the car.

Yes! Same issues different timings- below half a rank they popped. My dealership has the car now & is is working to identify.