Just a thought - can the chip be moved to the new key?
My 1996 312D needs 3 keys.
The ignition and the back door keys have YM0S or YMOS on them, the ignition has a merc logo on the back, longer shoulders and a bigger head. The teeth are quite different.
The key for the other doors is a JMA ME HMP with shoulders between the other 2 lengths.
The door keys are clearly not chipped, the ignition looks like it might be, the head is bigger and thicker and there is grey rectangle to one side if you look along the key towards the edge ofthe head. I was just wondering if this is the chip module and if so can it be carefully prised out and transferred to a new key? I know that on some newer car keys this is possible.
Feel free to tell me I'm an idiot if '96 sprinters don't have immobilisers - I'm still learning about it!
I know buying a car with different locks is always a case of buyer beware, but I figured that on a 16 year old van some wear and tear and replacement was to be expected, like the odd license plate lamps, missing check strap on the n/s rear door and missing bumper for the o/s rear door.
Also someone mentioned lubing their lock(s) just in case you didn't know, graphite powder is the best thing for this, forget oils and WD40 get some graphite lock lube. Mine is by Ambersil, it is a little spray that only holds a few grams of graphite but it goes a long way. I have heard that in a pinch ramming a pencil lead (without the timber casing) into a lock and then grinding up with the key can unjam a sticky lock - probably best to use a good quality pencil!
Jim