[hencini]

Okay, I know this sounds like a dumb question, but I'm trying to figure out why my fuel door lock actuator only unlocks and won't lock. I've looked through the Bentley manual and it really doesn't have much to say on the topic... The rest of the system works fine-- trunk, doors, etc.


Background: A little while back while I was bored on a Saturday afternoon, I decided to figure out why my fuel door lock didn't work. Obviously not a big deal, but like I said, I was bored...


So I pulled it out of its location and tested it while still connected to the harness by pressing the lock and unlock buttons on the key fob. It would unlock (retract) but not lock (extend).


Never having seen the inside of one of these things, I just figured the motor was shot or some gears were stripped or something, so I put it aside and bought one from a guy who was parting an e36.


Since the weather has been so cold, I didn't have time to put it in until today and the new actuator has the same problem... It will unlock but not lock... So I took one of them apart (see first photo), and it's pretty simple: the motor must spin in two different directions-- one to lock and the other to unlock. Well, the two I have only spin in one direction-- the unlock direction. It certainly could be coincidence, but I started thinking maybe it's something else-- problem in the Central Locking System somewhere...


The other thing I can't figure out is the role of the little blue capacitor-looking dealy (see second photo). I'm not exactly Mr. Small Electric Motor guy... I'm sure it doesn't have anything to do with the problem, I was just wondering why it's there...


So the heart of the matter is: is there some element of the Central Locking System that is in charge of telling the motor which way to spin? Maybe it reverses polarity depending on whether it needs to lock or unlock?


Thanks for any insight...

[ths916m3]

Originally Posted by hencini

Okay, I know this sounds like a dumb question, but I'm trying to figure out why my fuel door lock actuator only unlocks and won't lock. I've looked through the Bentley manual and it really doesn't have much to say on the topic... The rest of the system works fine-- trunk, doors, etc.


Background: A little while back while I was bored on a Saturday afternoon, I decided to figure out why my fuel door lock didn't work. Obviously not a big deal, but like I said, I was bored...


So I pulled it out of its location and tested it while still connected to the harness by pressing the lock and unlock buttons on the key fob. It would unlock (retract) but not lock (extend).


Never having seen the inside of one of these things, I just figured the motor was shot or some gears were stripped or something, so I put it aside and bought one from a guy who was parting an e36.


Since the weather has been so cold, I didn't have time to put it in until today and the new actuator has the same problem... It will unlock but not lock... So I took one of them apart (see first photo), and it's pretty simple: the motor must spin in two different directions-- one to lock and the other to unlock. Well, the two I have only spin in one direction-- the unlock direction. It certainly could be coincidence, but I started thinking maybe it's something else-- problem in the Central Locking System somewhere...


The other thing I can't figure out is the role of the little blue capacitor-looking dealy (see second photo). I'm not exactly Mr. Small Electric Motor guy... I'm sure it doesn't have anything to do with the problem, I was just wondering why it's there...


So the heart of the matter is: is there some element of the Central Locking System that is in charge of telling the motor which way to spin? Maybe it reverses polarity depending on whether it needs to lock or unlock?


Thanks for any insight...

I have no Idea mine is broke, but its better that it doesnt lock so you cant open it.

[hencini]

Well, I know many of you have been on the edge of your seats waiting for the solution here... It turns out that the PO-installed keyless entry system only puts the car in single-lock mode and the fuel door only locks under double-lock. See cool link.


In the neighborhood I live in, double-lock seems like a pretty good idea... I'll probably be doing this mod in the next week or so...

[Richardsperry]

Yep that's the one. Works like a champ.

[Tony Soprano]

this is what ive found from messing around with mine.

when i set the system to "chirp" when it locks and unlocks, it locks the fuel door. when i set it to silent it wont lock the gas door. odd.

[hencini]

Originally Posted by Tony Soprano

this is what ive found from messing around with mine.

when i set the system to "chirp" when it locks and unlocks, it locks the fuel door. when i set it to silent it wont lock the gas door. odd.

Is it an aftermarket system?