Non-Functioning IR Central Locking Feature

[MB-Dude]

Originally Posted by spinedoc

Hmm my center console roll top does not lock down, I'll have to take a closer look.

I always thought it was humorous that the Center Console Roll Top of my '96 SL600 locked down. In my car, the center console only has room for the two factory-installed cup holders. Are they *that* expensive that require them to be locked down when I'm not in the car?!?
Cheers (with LOL),
Jeff

[spinedoc]

Originally Posted by MB-Dude

I always thought it was humorous that the Center Console Roll Top of my '96 SL600 locked down. In my car, the center console only has room for the two factory-installed cup holders. Are they *that* expensive that require them to be locked down when I'm not in the car?!?
Cheers (with LOL),
Jeff

Lol, I agree, but my wife does keep her nice Pradas in there. I can hear the latch clicking, but it does not pop up, hmm.

[askay]

Solved it. I got a diagram of the vacuum locking system, traced the lines and found a break in the right rear storage compartment. I put a toothpick in that line to seal it, and voila!, I have locking in the console compartment, sliding cupholder compartment and eyeglasses storage in the dash. The door compartments no longer lock in the '96 model year.

[lynns]

Originally Posted by MB-Dude

The IR function for central locking in my ’96 SL600 has stopped working. My central locking feature works perfectly if the mechanical key is used in any of the locks. Thus, only the IR function is inoperable.

However, whenever I use the mechanical key to lock/unlock the car, the red/green lights on the rear view mirror are *not* blinking. I cannot remember if they blink whenever a mechanical key is used, or whether they are for IR operations only.

Any and all input is welcomed! Thanks in advance.

Jeff, while researching something closely related I came up with this PDF from my R129 Service DVD. It looks like the PSE vacume pump is known for failure and something for you to consider. Please read the attached PDF. p/n 1298000848 is $388.70 at www************

[askay]

This deserves some closure. I got a diagram of the central locking system, started tracing the vacuum lines, and found a broken connection in the right (passenger-side) rear storage compartment. I put a toothpick into that line and voila!: I have locking internal compartments.

Thanks again for the help. I'm reminded once again that none of us is as smart as all of us.

Alan

[MB-Dude]

Originally Posted by lynns

Jeff, while researching something closely related I came up with this PDF from my R129 Service DVD. It looks like the PSE vacume pump is known for failure and soething for you to consider. Please read the attached PDF. p/n 1298000848 is $388.70 at www************

Thanks Lynn for the great information - I'll check it out!
Cheers,
Jeff

[MB-Dude]

Although it has been a while, the problem turned out to be a bad key remote. With nothing else to try or check, I 'bit the bullet' and purchased a replacement key remote from the local delaer. Problem fixed. Guess they do wear out over time, though I'm not sure how.
Cheers,
Jeff

[ctaylor738]

This has been dormant for a while, but it is still the best thread on this issue, so I thought I would post what I learned trouble-shooting my '96 SL 500.

1. You can test the remote easily with an i-Phone. Just view it like you are taking a picture and press the remote's button, and you will see a flash if the remote is working.

2. The remote lock/unlock flow is from the receiver under the mirror to the remote control lock (RCL) module (n54/1) behind the passenger air bag.

3. The RCL sends a signal to the PSE (vacuum) pump controller to tell the pump to unlock the doors and trunk.

4. It also (I believe) via the CAN, tells the rest of the electronics that the vehicle is unlocked and it is OK to provide fuel and spark when the key is turned to start.

If the remote is transmitting, the next step is to see if the receiver is signalling the RCL module. This can be tested by probing the green/violet wire (pin 7 on the RCL) and connecting a meter between it and ground. You should see app. 12 v. which will drop by about a volt when the remote is pressed.

The location of the RCL moved around in the 90's. Up to '95, it is supposedly in the trunk by the fuel fill. In '96, it moved behind the passenger air bag and is accessed by removing the plasic under-panel. That's where I found it on my car. In later years it supposedly moved to the left of the sterring wheel.

On my car, there is a twelve-pin connector and separate two-pin connector for the CAN.