Help 1997 c280 stuck in park - PeachParts Mercedes-Benz Forum

ykobayashi · #1 04-05-2025, 01:52 AM

Hi,

I cannot get my shifter out of park. Here is some background.

My key got jammed in the ignition. There was no way I could turn it and I ended up having to remove the lower kick panel and grind out the steering lock by grinding down the little pin with a dremel and wiggling the lock out. It was a PITA job but it was pretty doable.

I replaced the lock mechanism and key tumbler and the car starts fine now with the old key. But now I cannot get it out of park. It is jammed with some kind of safety interlock I believe.

When I was down removing the mechanical cable from the steering lock (presumably the function is to prevent shifting) I pressed it a couple of times and tried to work the shifter. My intent was to get the car into neutral so I could move it around in my garage to get more room to work. I may have messed something up in the shifter mechanism while doing this. I didn’t force anything but I noticed when I pressed the plunger in the ignition side of the shifter cable the shifter still didn’t move. Perhaps on this car the brake needs to be pressed too to get the lever to release. Anyhow I’m mentioning this because maybe that mucked up the interlock operation.

When I installed the lock I made sure I installed the little mechanical cable. It just screwed in and seemed pretty foolproof. I checked the mechanism on my dead lock and it is just a cam that pushes the plunger when the key is turned. I don’t think it is possible to install it incorrectly.

I’m thinking I mucked up something with the cable and shifter mechanism. I believe the entire safety system (brake + keyway cable) is completely mechanical on this car. I may be wrong though and I intend to tear down my shifter control tomorrow to see how it works.

My next step tomorrow is to take the shift console apart and see what those cables do down there (assuming they are going to a mechanical interlock at the shift lever).

If you guys have any knowledge of this system I’d appreciate a tip. I’m pretty flustered after spending the better part of two days swapping the lock and still having the car stuck in the garage.

Thanks.

tyl604 · #2 04-05-2025, 11:15 AM

Isn't there some kind of removable small round hole cover on the console, near the shifter? You just use a screwdriver to push a button down inside the hole, and the shifter will release. Most automatics have some form of this.

Just wondering.

Sugar Bear · #3 04-05-2025, 12:18 PM

Look under the shifter boot cover for a yellow plastic tab toward the rear of the shifter, push it down and it should release the shifter.

Yes the brake pedal must be depressed to shift out of Park.

Let us know ...

ykobayashi · #4 04-05-2025, 04:37 PM

Solved it. No guys, on my car there isn’t an emergency door. Even if there was it wouldn’t have solved the underlying problem.

So what was it? The steering lock I bought was used. It had a switch screwed to the back so I figured I was good to go. But it didn’t have the internal cam that pushes the park cable. I totally missed that and just installed it. Diagnosing I just followed the cables which all meet at the brake mechanism. I turned the key and pumped the brake till I understood how it worked. What was readily apparent is the cable coming out of the ignition lock was disturbingly motionless. So I pulled the cable and peeked in there with an inspection mirror and there was no cam.

My bad, I should have checked it all out on the bench first. Now I had to do it all twice. Good practice I guess.

So I put in a new core. Keyed it to my old door and trunk lock. Cut two new keys on my CNC mill. My local key guy refused to cut the narrow 1990s keys. He did the W126/124 keys on his Lazer machine but he said the new ones are too narrow.

I got these key vise jaws specifically for HU64 blanks. Ten blanks. I digitized my last good key and made toolpaths and cut the keys with a 0.125” end mill. It is supposed to be 0.100” but I must have been close enough because my keys work great.

Homebrew and OE.

Unfortunately my brand new key exposed my worn out ignition cylinder. It was on its way out and my freshly cut keys kicked it over the edge. I wish I took it out when it was still turning but it jammed up really good and I had to cut it out of the car. (Right, I’m dumb). Basically the keys and the tumbler were done. I was really stupid trying to get by with just new keys. Removal wasn’t as bad as I thought. I used a Dremel with one of those rotary hand piece tools on a cable. Took twenty minutes to cut the old one out. But it has taken two days to install the new one due to this park interlock debacle. Just getting to the lock takes me an hour.

I did learn about how these interlocks work. There is a cable from the ignition which goes to a contraption on the brake. It’s kind of mechanical AND gate that combines the state of the brake pedal and the ignition lock. Then it has some linkages and levers that send the “signal” on another cable to the transmission where it activates a lock on transmission shift lever.

I’m not sure but there are some switches on the brake pedal mechanism like brake switches that likely sends the same information to an electronic controller. On my car the shift lever is appears to be locked out using an electrical solenoid. I have not verified this on my car but I looked at a lot of 1997 c280 shift assemblies for sale on eBay and none of them have actual cables like a w124 or w201. So I was wrong on my first post saying it was all mechanical. It seems to be a mix.

Well, that’s enough for now. I’m going to enjoy the car a bit. I put in new oil and trans fluid. Hoping it won’t give me much trouble.

Thanks for getting back so fast. I was up all night trying to guess what went wrong using internet searches. It just took some in person detective work to see just what was jamming up the shifter.