Coding your GM locking gas cap DIY

[Malibu T]

Has wk'd like a charm for months... until this fuel stop! I inserted key, turned to unlock, and cap wouldn't come off. I attempted to turn key back into locked position (so I could take key out & try again), but it wouldn't budge! I quickly realized:
1. couldn't get key out!
2. couldn't get cap off, fuel up, or shut fuel door & drive away... even if my husband brought me the spare key!!
It was embarrassing when the gentleman at the pump next to me realized I was having an issue. He managed to get the cap off, but still could not turn or remove the key from the lock. ...long story short, I cursed it & hit the cap several times while yanking on the key fob, and eventually got the key out. BUT it sounded like I was pulling it out of a pile of rocks? I fueled up, & had no choice except to put the cap back on. (Had a 40+ mile drive home).

Question: My husband said shoot WD40 in lock & try to insert the key again. I'm just a bit gun shy to do that without a backup cap with me. Have any of you had a similar problem with yours? There's a lot of plastic inside that cap... Wouldnt it be better to dip key into a bit of detailer spray (silicone based), instead of using a petroleum product to lubricate the lock? I'm thinking with all of the rain, heat, & humidity lately, maybe it's just oxidation on the metal housing causing tumblers to stick?

[Eddiefuzz]

Originally Posted by Malibu T

Has wk'd like a charm for months... until this fuel stop! I inserted key, turned to unlock, and cap wouldn't come off. I attempted to turn key back into locked position (so I could take key out & try again), but it wouldn't budge! I quickly realized:
1. couldn't get key out!
2. couldn't get cap off, fuel up, or shut fuel door & drive away... even if my husband brought me the spare key!!
It was embarrassing when the gentleman at the pump next to me realized I was having an issue. He managed to get the cap off, but still could not turn or remove the key from the lock. ...long story short, I cursed it & hit the cap several times while yanking on the key fob, and eventually got the key out. BUT it sounded like I was pulling it out of a pile of rocks? I fueled up, & had no choice except to put the cap back on. (Had a 40+ mile drive home).

Question: My husband said shoot WD40 in lock & try to insert the key again. I'm just a bit gun shy to do that without a backup cap with me. Have any of you had a similar problem with yours? There's a lot of plastic inside that cap... Wouldnt it be better to dip key into a bit of detailer spray (silicone based), instead of using a petroleum product to lubricate the lock? I'm thinking with all of the rain, heat, & humidity lately, maybe it's just oxidation on the metal housing causing tumblers to stick?

Listen to your husband!

[Malibu T]

Originally Posted by Eddiefuzz

Listen to your husband!

Alright, will give it a go... after I make him a sammich. (Dug my original cap out of the attic, just in case though!)

[GVA 45TH 2SS]

Try the WD40. there was someone back when I first posted this that had an issue with the key sticking in the cap. But I think it was not coded properly or not seated right, he managed to pull the whole tumbler out.
The key will be captive if you turn it, I would push the key in and out a few times with WD40 on it.
without turning it and see how it feels.
if it feels alright try turning it slightly then back and remove the key.
i would be cautious if it sounded that bad, maybe a spring broke. but it could just be dry.

[Car.freaks]

Thanks for the DIY write up. I did it but it took me about an hour. 10 minutes is a little optimistic. After I got the tumblers set i went to put the springs in and then I had to change the tumblers so they fit right. So glad to have a locking cap. People are jealous as hell that you have a nice car and I don't need sugar in my tank.

[ZL1crush]

Excellent article thank you for including the part numbers as well. I checked the gas cap on my 2013 SS and it fits on my just acquired 2015 ZL1 so I'm ordering the AC Delco part # you provided to put on the ZL1.

[ROCNDAV]

Almost 12 years later and this thread is still helping people. I just want to thank you for your great Instructions and pictures.

The instructions that came with mine sucked. Thanks again. Had it set up in 10 minutes

[el ess A]

23159210, GT344. Still available from stealerships.

List price today is 125.70. But you can still get it from most places for around 70 plus shipping! (68 and change on ebay) I bought up several of them back in the day for around 14.95 each from the Rock right before the price went skyrocketing up. Still got them on both Camaros. Sold off my last two in 2016. I think I did keep one spare kit.