Hello everyone! I just walked out into my garage, where my Touring has been parked for 5 hours or so, and heard something like a small pump motor running. It seemed like it was coming from the rear. By the time I went back in to get my phone to record it, it shut off. Any ideas what this is? It seemed quite odd.
mrutherf
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I have no idea how you came to that conclusion. That part number I posted most certainly is not the low-pressure fuel pump. The fuel pump cannot pressurize the tank with air to check for leaks; how could it? It's job is to pressurize the fuel lines... where would it even get air to pressurize with?
As far as an error message goes? You'd get an evap-emissions related code, of course, probably "Small/Large Leak Detected" would be the most likely.
They use the vapor pressure from the fuel. To determine the size of a small leak they modulate the solenoid and monitor the pressure drop, this provides a reference leak size. They can then monitor the tank pressure and determine if a leak is large enough to trip a code. This is called a "key off" leak test. This can only be done if the conditions are right, car has to be sitting for several hours and the temperature has to be high enough to create a mearsurable vapor pressure.
That's the sound of The electromechanical parts in the leak detection unit doing their thing.
I rec'd an answer from Honda today for 2017 CR-V. There is a ServiceNews Article for Jan 2017 which says " Noise from Under Vehicle: This noise is caused by the vacuum pump inside the fuel evaporation leakage check module (ELCM). Depending on conditions, the pump will come on for about 15 min about 5 to 10 hours after engine shutoff. These are normal noises and don't indicate a vehicle problem."
Which is what hans471 stated. Now we have an explanation from Honda. So far mine has come on for about 1 min. 5 hrs after shut off.
Which is what hans471 stated. Now we have an explanation from Honda. So far mine has come on for about 1 min. 5 hrs after shut off.
Answer to question under vehicle noise question
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After Shutting off the vehicle you may hear certain noises coming from the vehicle. Here's the lowdown:
- Noise Under Vehicle: This noise is caused by the vacuum pump inside the fuel evaporation leakage check module (ELCM). Depending on conditions, the pump will come on for about 15 minutes about 5 to 10 hours after engine Shutoff.
- Clicking from Under Hood: This noise is caused by the electric brake booster (EBB) system. The system will come on for about 3 minutes every time the door is opened.
Keep in mind both of these noises are just normal vehicle operation and don't indication a vehicle problem.
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Hope that helps others not go through the same fretting some of us here have......
I just came from the dealer who checked it out and handed me a copy of the 'ServiceNews Article'. It outlines two sounds that are normal. The first is the one we're discussing here.
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After Shutting off the vehicle you may hear certain noises coming from the vehicle. Here's the lowdown:
- Noise Under Vehicle: This noise is caused by the vacuum pump inside the fuel evaporation leakage check module (ELCM). Depending on conditions, the pump will come on for about 15 minutes about 5 to 10 hours after engine Shutoff.
- Clicking from Under Hood: This noise is caused by the electric brake booster (EBB) system. The system will come on for about 3 minutes every time the door is opened.
Keep in mind both of these noises are just normal vehicle operation and don't indication a vehicle problem.
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Hope that helps others not go through the same fretting some of us here have......
What???
Does it say it will come on just once in that 5 to 10 hour period, or does it come on multiple times for 15 minutes each time?
Just once. I don't know how you'd read it otherwise.
I initially thought you meant just once, but wasn't sure, so I asked.
The vacuum test is common on many cars. Its part of OBD II requirements where the car has to detect if there is a fuel vapor leak in the system. To do this they have to wait until the engine is off and the car has sat long enough that it is normalized at ambient temperatures. (This prevents false fails from changing vapor pressures in the tank). Once the car has sat the appropriate amount of time the ECM will shut the canister purge valve and the the intake vent valve, sealing off the tank. Then it will turn on a vacuum pump that will put a "vacuum" on the fuel tank. It will then shut down and the pressure sensor in the tank will look for a drop in the amount of vacuum. You do NOT want to put pressure on it! If there were a leak you would be shooting fuel out of the tank...stop and think about that.
Several conditions have to be met before this test will run. The tank can't be too full or too empty. The ambient temperature needs to be in the correct range. If you do it when its too hot the fuel will vaporized and change the pressure in the tank. So, the time window when this test runs can change based on environmental conditions. The test does not run every time you turn the car off, only when certain criteria is met. You can learn more about this code by looking up "OBD-II Small Leak Detection"
Several conditions have to be met before this test will run. The tank can't be too full or too empty. The ambient temperature needs to be in the correct range. If you do it when its too hot the fuel will vaporized and change the pressure in the tank. So, the time window when this test runs can change based on environmental conditions. The test does not run every time you turn the car off, only when certain criteria is met. You can learn more about this code by looking up "OBD-II Small Leak Detection"
I have heard the noise (buzzing/humming) on my 2017 touring twice. Both times it sounds like it's closer to the rear of the vehicle. The car had been off for more than 3-4 hours each time. Both times i pushed the auto rear tailgate to open. Then i close it. The noise stopped right after both times. Are we sure this isn't a motor issue in the auto tailgates?
Thank you! I'm a new owner of a 2018 EX model and having come from a 2006 Ford Escape, I have a learning curve with my new vehicle. I couldn't figure out that clicking noise I was hearing from the hood when I get into my vehicle, now I know what it is. Very informative group I see. I'll learn things about my new ride.
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Have a 2017 EX and have noticed this sound, like a very small compressor running, several hours after running up here in northern NH in the winter, parked in the unheated-but-warmer-than-outside garage. Glad to learn that it's a normal test running; I thought it might be part of the fuel vapor collection system and it is, well-explained by the 1-10-2018 post by hans471+ . Thanks.
Buzzing noise
Just another one here to add my two cents to it. We've heard the noise a couple of times on our 2018 EX-L. We originally thought it had to do with the tailgate, but today it didn't stop when I opened it. So I came here and found the explanation. Thanks to all who did the research!
Just another one here to add my two cents to it. We've heard the noise a couple of times on our 2018 EX-L. We originally thought it had to do with the tailgate, but today it didn't stop when I opened it. So I came here and found the explanation. Thanks to all who did the research!
So thankful to find this post. We have discovered this noise twice now in about a year. Once was in summer and 2nd time was recently in cold weather. Car is in garage and off for several hours. Good to know about emissions testing. I can stop worrying now thank you!
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