Car door lock is not working

2004 Honda Accord LX with a 2.4 liter engine 220,000 miles. So my key does not turn when I try to unlock my door(i get in through my trunk everyday haha). My mechanic said its probably the lock actuator, so I was wondering, is it hard to change the lock actuator myself? And also if my key fob battery is bad would it be better to buy the battery for the key fob instead of getting the actuator? I just hope it’s the actuator because I seen it could be that or something else forgot the name though. But if I get a fob it really wouldn’t matter about the part because i can just lock and unlock it with the fob which honestly I’d rather use my key in the key hole.

Whether you replace the door lock cylinder or actuator, the inner door panel has to be removed and the vapor barrier peeled away.


The two main problems I’ve had to solve when fixing something inside a car door panel

  • Removing the door card without breaking the plastic fasteners. It is very easy to break them prying w/ a screwdriver. There are tools esp designed for this . This is the one I use.
  • Removing the window up/down crank handle. I presume you have electric windows, so good news, you won’t have that problem.
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Thanks, do you think either one would work or do you think it could be either or and I’ll have to check to see which one it is and fix that part? But I’ll watch the video and I’ll see if I can do it myself thanks again for this

I’m still puzzled why you get in via the trunk. Isn’t there a key-lock on the passenger side? If not, how do you get in via the trunk?

Does the key work on the passenger door?


@George_San_Jose1 yeah I’ll have to get these pieces. I plan on buy a lot of stuff this weekend cause I really don’t have any tools.

My passenger side doesn’t have any lock on it to open it. only my driver door has this. I open my trunk with my key and I unlock my back door and then just go and unlock my driver door

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Just a word of caution: B/c of the electrical components involved, this fix may be a little too complicated for a first time car-diy’er. Probably best to hire it out, or at least find someone experienced to help you.

This fix is not complicated.

Everything unplugs and plugs back in.

But, the opening in the door has sharp edges, and some components may be hard to reach.

Most mechanics wear a set arm chaps when doing this type of repair so they don’t get cut.



Put a battery in your FOB. If the actuator works after putting in a new battery, then issue is the lock cylinder which I suspect will be the case. You could try spraying a little oil in the lock cylinder to see if that frees it up but more likely one of the key cylinders has a broken spring.

New battery for the FOB about $2, new actuator, $200 just for the part, and that was about 20 years ago so it may be more. Do everything else first before you jump on the most expensive part.


That right there tells me it’s the lock cylinder.

I change all my fob, remote, and other batteries once a year, whether they need it or not. That’s also when I blow out all the smoke detectors. Usually on new years.

It was a little unclear if your fob doesn’t work or putting the key in the lock doesn’t work, or if any of these just don’t activate the actuator. I also lube my locks once a year when changing batteries. So depending on the actual issue depends on whether you have to open up the door.

Did you lube the lock cylinder yet? That might be all you need. You can lube it through the keyhole then give it a few hours to overnight to move through the mechanism.

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Anything specific to spray it with? I think I tried spraying my key then putting it in the lock and nothing changed. But honestly i don’t know if a new battery for the key fob is 2 dollars

Any oil in a spray can, use plenty of it, spray it all over on the inside. It will either work or not but it wont hurt it any more than it already is.

If your battery is a 2032, they are about $3 each or less depending on how many you buy. A 2 pack at wally world is about $6.

Your owners manual explains how to replace it.

Do NOT use any liquid base product to lube your lock cylinder.


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Use a dry graphite lube.


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I rub my key’s surfaces with a pencil once in a while, before inserting it into the lock. Seems to help keep the inner mechanism turning freely. Works better with softer lead pencils, like those little stubby ones you can get for free at golf courses and libraries. Given the description of the symptom however, I doubt that will work in OP’s case. But easy enough to give it a try, might get lucky.

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You have a worn cylinder and/or the key. It’s a 20min job to replace it (new cylinder will come with its own key).