[outsidepls]

We're supposed to leave on a camping trip today. I went to fill up the car and it took a few button presses to get the gas flap to open. Filled up, left the station and immediately check engine light came on. Thinking the attendant (it's Oregon) didn't tighten the cap all the way, I pulled over to check, but the flap wouldn't open at all. I tried the green cable in the trunk, still won't open. Service center is booked through next week and I'm not confident we can get through this trip on one tank of gas (plus the gas cap is probably loose). Any ideas?

[ScaldedDog]

Yeah, these things are awful, and the green release is worthless. Keep pressing the button and bang on the flap.

Mark

[outsidepls]

Originally Posted by ScaldedDog

Yeah, these things are awful, and the green release is worthless. Keep pressing the button and bang on the flap.

Mark

Banged pressed and pulled as much as I felt comfortable with. Trying to get a walk-in service appointment now but I don't have a lot of hope. Blergh.

[streborx]

The flap catch is coupled with the car's locking system. You might try cycling the locks between lock and unlock a couple times to see if this frees it up.

[jad03060]

On the PHEV, the gas cover is interlocked with a pressure sensor so you can't open the door until the sensor sees the pressure is reduced by hitting the button first on the driver's door. Then, if the vehicle is unlocked, you can open the door and get to the cap.

[ScaldedDog]

Originally Posted by outsidepls

Banged pressed and pulled as much as I felt comfortable with. Trying to get a walk-in service appointment now but I don't have a lot of hope. Blergh.

I whacked mine pretty hard with the heal of my fist to get it to open.

You might try having someone pull on the worthless emergency release 'till they feel the actuator move, then you whack the door. Be careful, as that green actuator is just a thin plastic wire that would be an embarrassment in a low-end econobox.

For what it's worth, mine has done this twice, and both times the tank was fairly full. I was just wanting to top it off before a trip.

The whole issue is ridiculous in any car, much less an $80K one. The button has *one job* - simply open the door. Anything else it thinks it needs to do is distantly secondary to that. If we are so dumb we don't know how to open a pressurized tank - and you only do that wrong once - we have no business driving.

Mark

[eelnoraa]

Originally Posted by ScaldedDog

I whacked mine pretty hard with the heal of my fist to get it to open.

You might try having someone pull on the worthless emergency release 'till they feel the actuator move, then you whack the door. Be careful, as that green actuator is just a thin plastic wire that would be an embarrassment in a low-end econobox.

For what it's worth, mine has done this twice, and both times the tank was fairly full. I was just wanting to top it off before a trip.

The whole issue is ridiculous in any car, much less an $80K one. The button has *one job* - simply open the door. Anything else it thinks it needs to do is distantly secondary to that. If we are so dumb we don't know how to open a pressurized tank - and you only do that wrong once - we have no business driving.

Mark

Yes, that green thing needs to be pulled very hard to disengage that door latch, much harder than once would feel comfortable. If you ask me, it is an over engineering un-necessity that BMW does. I don't think Rav4 prime has such a mechanism. As every car has pressurized tank. It just needs to turn on ICE to depressurize. And what is wrong with opening tank without depressurized?? Prior to mid 90s, cars has steel tanks and no Evap system. We simply just open cap with a slight hiss if tank is relatively full.

[kennewman]

Originally Posted by outsidepls

We're supposed to leave on a camping trip today. I went to fill up the car and it took a few button presses to get the gas flap to open. Filled up, left the station and immediately check engine light came on. Thinking the attendant (it's Oregon) didn't tighten the cap all the way, I pulled over to check, but the flap wouldn't open at all. I tried the green cable in the trunk, still won't open. Service center is booked through next week and I'm not confident we can get through this trip on one tank of gas (plus the gas cap is probably loose). Any ideas?

I just recently got a 2021 X5 45e and the first time I went to fill up, this exact same thing happened…I called the dealer and his advice was to hold in the release button for a while….I pulled quote vigorously on the little green thing, to no avail…..but then magically after I got off the phone, I pounded pretty hard on the flap and it opened!

Did a second fillup a couple of days later with zero issues…it acted just like the manual said it would!

Oh, the dealer also suggested trying to push the release button a few minutes prior to when you want to release….

Silly stufff, if you ask me!

[streborx]

Originally Posted by jad03060

On the PHEV, the gas cover is interlocked with a pressure sensor so you can't open the door until the sensor sees the pressure is reduced by hitting the button first on the driver's door. Then, if the vehicle is unlocked, you can open the door and get to the cap.

What's the intended purpose of the pressure sensor? If a loose gas cap triggers a CEL, would there not be zero pressure? Just trying to understand things.

[nZtiZia]

Originally Posted by outsidepls

We're supposed to leave on a camping trip today. I went to fill up the car and it took a few button presses to get the gas flap to open. Filled up, left the station and immediately check engine light came on. Thinking the attendant (it's Oregon) didn't tighten the cap all the way, I pulled over to check, but the flap wouldn't open at all. I tried the green cable in the trunk, still won't open. Service center is booked through next week and I'm not confident we can get through this trip on one tank of gas (plus the gas cap is probably loose). Any ideas?

I’m assuming you vented the tank (pushed the depressurization button on the driver door) before attempting to open the fuel filler flap?

[jad03060]

In a typical ICE gas tank, there's an activated carbon filter that is there to absorb gas fumes. During normal running, those stored fumes get fed to the engine so it's ready for the next idle period. There's a one-way air inlet to allow the tank to not become a vacuum as you use fuel. The PHEV, since you might go months between using any fuel, there could end up being a fair amount of gas vapors above the liquid. Relieving that pressure is better for the environment. I do not know where those fumes actually go, but may end up being stored, and not vented into the atmosphere. If you were foolish enough to be smoking while opening the gas cap, the pressure wave of rich fuel vapors could be quite dramatic! So, likely for environmental and safety reasons, the PHEV must relieve the pressure in the tank prior to allowing you to open the door, which gives access to the cap, preventing issues.

The button on the door does not pop the filler door open, it relieves the pressure and enables the locking pin to retract, so you can then open the door to get to the cap to refill the tank. IOW, it's not directly a door release button you might find on other vehicles.

[nZtiZia]

Originally Posted by jad03060

…
The button on the door does not pop the filler door open, it relieves the pressure and enables the locking pin to retract, so you can then open the door to get to the cap to refill the tank. IOW, it's not directly a door release button you might find on other vehicles.

good point. so when folks have this issue enough to bring their vehicle for service, they could word it that the system isn’t de-pressurizing properly which prevents the door from opening, and not simply say the button isn’t unlocking the door

[jad03060]

Anyone old enough to remember the BurmaShave signs? One that still sticks in my mind is:
"He lit a match...to check his gas tank...and that's why they call him... Skinless Frank...Burma Shave"

If you've not experienced them, they were a series of small signs along the side of the road that broke various ditties up sequentially. Sort of broke the boredom of a kid (or maybe adult!?) on a road trip before Interstates added more to the boredom and they were relegated to smaller roads.

There's a reason why BMW requires the gas tank to be depressurized prior to allowing you to open the cap.

[RickObe]

Originally Posted by ScaldedDog

For what it's worth, mine has done this twice, and both times the tank was fairly full. I was just wanting to top it off before a trip.
Mark

So in this and the OP's case, the tank was full. I wonder if that somehow prevents it from being depressurized enough or somehow prevents the sensor from knowing it's depressurized enough.

[ScaldedDog]

Originally Posted by RickObe

So in this and the OP's case, the tank was full. I wonder if that somehow prevents it from being depressurized enough or somehow prevents the sensor from knowing it's depressurized enough.

Perhaps, but that means it's not just nanny technology, but crap nanny technology. Particularly since the "emergency release" not only doesn't work, but is so fragile as to be nearly single use.

Mark

[streborx]

Pressure sensing and pull cord emergency flap release sound like bandaid fixes to problems discovered late in the design. Probably why the OMs tell you to see a dealer if your flap is stuck -- $90K+ automobile with problems too humiliating to confess openly.

[eelnoraa]

Originally Posted by streborx

Pressure sensing and pull cord emergency flap release sound like bandaid fixes to problems discovered late in the design. Probably why the OMs tell you to see a dealer if your flap is stuck -- $90K+ automobile with problems too humiliating to confess openly.

I don’t think this is a late discovery or after the fact fix. Car gas tank being pressurized is a know fact since I ever started driving. My guess is one or a few “smart” system design guys at bmw just pulled a scheme out of their *ss, without considering real life usage. It is “engineers designed a product for engineers. If they every go test a rav4 prime, Prius or Pacifica hybrid, they should know there are far simpler way to do the same thing.

Back to gas vapor type of topics. There are just so many bad info here. People who has never work on a engine for one day try to educate the community, laughable as always. Gasoline is a very easy Ti vaporizer substance. After maybe a night of parking, tank will reach equilibrium, tank pressure will reach a point where no more gas will vaporize. This steady state pressure is a function of temperature, not time. It is probable a single digit psi above ambient in normal temperature range. If pressures increase to a point, the cap itself has a relief mechanism as well. Opening gas cap in PHEV is not any different than opening gas cap on an ice car after park for a while. The handling is the vapor release is probably governed by epa. But the overly complicated way of handling it is choice by bmw.

This thing happened to me once. It was on the return leg of road trip from south CA back to north CA. Highway 5 middle of no where, rolled into gas station at 10pm and couldn’t open flap. It was a panic moment. After trying a few thing, I eventually used a fine needle point tweezer to pick open the flap. Luckily kids were sleeping, so we could have a quiet moment to think mitigation. Now I am planning to replace the green plastic string with a 1/8” stainless steel wire, so I can be sure it will pull open.

[nZtiZia]

can any X5 30d, 40i, m50i chime in to my question?

do you have a button that’s required to be pressed prior to opening the fuel flap (door)?

if not, then my next question is to elnoraao2:

couldn’t it be argued the PHEV is designed with such a button because it’s not serving the same function as opening the gas cap to vent the fuel tank? you say all fuel tanks equalize after some time. if that’s the case, then i should be able to open the fuel flap on my unlocked 45e that’s been sitting overnight in my 75° garage… BUT I JUST TRIED AND I CAN’T. I had to press the button first which then took about 10 seconds before it unlocked

[eelnoraa]

Originally Posted by nZtiZia

can any X5 30d, 40i, m50i chime in to my question?

do you have a button that’s required to be pressed prior to opening the fuel flap (door)?

if not, then my next question is to elnoraao2:

couldn’t it be argued the PHEV is designed with such a button because it’s not serving the same function as opening the gas cap to vent the fuel tank? you say all fuel tanks equalize after some time. if that’s the case, then i should be able to open the fuel flap on my unlocked 45e that’s been sitting overnight in my 75° garage… BUT I JUST TRIED AND I CAN’T. I had to press the button first which then took about 10 seconds before it unlocked

Not an owner of the cars you listed, but I have a few older bmws. None need that button to open flap. It just open when car is close unlocked.

You also ask 30d, diesel engine. Diesel is more of an oil substance than a solvent substance. Diesel doesn’t not generate any meaningful vapor, probably 1% of what gasoline will generate. So then need to equalize diesel tank is basically zero.

By equalize, I mean equilibrium point where pressure inside tank will prevent more gasoline vaporized. The pressure inside will still be greater, but not by much. Gasoline does not unlimitedly vaporize in a confirmed space. The cap is very safe to open even without depressurize. The cap’s mechanism to release pressure will still exist, it is a bit over pressure protection mechanism. All car’s cap does that.

I am not saying equalization is a bad thing, it is a nice to have. There are plenty of way to do it. BMW’s way is if equalization fail, you are not getting gas, this is messed up. When I roll into gas station, I probably really need gas. It is a small nice to have consideration that can strand a family on road. This is what sucks.

Btw, the reason 45e/530e/330e, use a steel tank, I just learned it has nothing to do with the drive train. But that is another topics.

[jad03060]

Only the BMW PHEVs have the button to enable the gas flap to open.

[jad03060]

While we can argue about why the PHEV have the pressure release button to enable unlocking the filler flap, or if it's required, we also have to note that BMW did not include a similar system for their ICE vehicles. I think we can also agree that it does not make much sense to add complexity for no reason. Whether BMW followed that rule or not, I would like to believe they have a valid reason for the expenditure of designing a special module, writing the software, and including the switch. The training guide does say this about the fuel system:
"2.3. Fuel supply
The G05 PHEV too has a stainless steel pressurized fuel tank. Unlike in the predecessor, the pressurized fuel tank is not secured to the
underbody, but is instead located underneath the luggage
compartment (like G12 PHEV and G30 PHEV)."

Regarding the tank vent, the user's manual says this:
"The vehicle is equipped with a special fuel tank.
The fuel tank is designed for special requirements
that arise from hybrid operation of the vehicle,
i.e., alternating drive with combustion engine
or electric motor."

[streborx]

Originally Posted by jad03060

While we can argue about why the PHEV have the pressure release button to enable unlocking the filler flap, or if it's required, we also have to note that BMW did not include a similar system for their ICE vehicles. I think we can also agree that it does not make much sense to add complexity for no reason. Whether BMW followed that rule or not, I would like to believe they have a valid reason for the expenditure of designing a special module, writing the software, and including the switch. The training guide does say this about the fuel system:
"2.3. Fuel supply
The G05 PHEV too has a stainless steel pressurized fuel tank. Unlike in the predecessor, the pressurized fuel tank is not secured to the
underbody, but is instead located underneath the luggage
compartment (like G12 PHEV and G30 PHEV)."

Regarding the tank vent, the user's manual says this:
"The vehicle is equipped with a special fuel tank.
The fuel tank is designed for special requirements
that arise from hybrid operation of the vehicle,
i.e., alternating drive with combustion engine
or electric motor."

This is very interesting and possibly explains the phenomenon. Fuel tank pressure is the result of active fuel tank pressurization rather than passive vapor buildup. I'm guessing during hybrid electric mode operation, the fuel pumps shut down and fuel line pressure would be otherwise lost. Pressurizing the fuel tank and system allows for faster ICE startup not having to wait for the pumps to pressurize the system. Still it would seem a better design would be automatic de-pressurization when shutting off the vehicle for refueling. A pressure release button and an emergency fuel flap door release seem a rather primitive afterthought.