Antitheft chip removal 1992 500SL.. .which chip?

[JRVAULTS]

It's a long story but I'm good at writing them so here goes...a friend of mine had a nice 500SL (one was a SL500 and the other 500SL I can't remember which was which) and had parked behind my motorhome on my little brothers property before we sold it. I got into the motorhome and backed into the fender...luckily we had one on the property with the same body style and even the same color. I pulled the fender and swapped them and then had the dented one fixed which is shown in this picture after it got fixed.

A few weeks later same person was having ASR issues and wrecked on freeway going 90...munched everything but the engine....he had it towed to the property and since it was being sold we were on a time crunch to get needed parts from his to complete the one in the picture....when we tried to start it...it turned over and over and over and over...would not start.

We finally realized it was because we didn't have the key. I just talked to him today and told him about using the heat gun to remove the antitheft chip so it will start without the key fob like I seen in the video but now I can't find the video. Don't worry I had the title for the car just not the key.

 

[JRVAULTS]

I'm sorry 1992 is the year

 

[gsxr]

1992 models didn't have the anti-theft system, DAS (Drive Authorization System). This didn't get phased into North America until 1996 USA model year.

Since it cranks over, try squirting a little starting fluid down the intake throttle body. If it tries to fire, the problem is fuel delivery. If it doesn't fire on starting fluid either, the problem is spark / ignition.

 

[gerryvz]

I concur, there is zero antitheft capability (save for the factory alarm) that is in a 1992 500SL. And this is simple to completely disconnect, just by unplugging a plug from the alarm module, if you want to.

This is a KE-Jetronic engine, so you should ensure that you have fuel flow to the fuel distributor via the fuel pumps. You can check this by jumpering the fuel pump relay sockets that control power to the fuel pumps, and then cracking a couple of individual fuel lines going into the top of the fuel distributor (just crack them, don't dramatically loosen them) and see if any fuel drops leak out.

If you have fuel, then you want to check spark per the two coils and twin distributors.

You should also easily be able to hot-jump the starter with a bridge wire -- no key should be required.

 

[JRVAULTS]

This is a problem that has lasted a full year and both my friend and I have done enough engine work to understand you need fuel and spark. It turns over and sounds great...just no spark because of no key fob. I am 90% sure when I was checking videos about removing eprom chip I ran across a video showing a guy using foil to cover everything except the little theft chip and he used a heat gun to soften and remove it from the board. If I'm not mistaken chip is also in the LH module.

 

[JRVAULTS]

This is a problem that has lasted a full year and both my friend and I have done enough engine work to understand you need fuel and spark. It turns over and sounds great...just no spark because of no key fob. I am 90% sure when I was checking videos about removing eprom chip I ran across a video showing a guy using foil to cover everything except the little theft chip and he used a heat gun to soften and remove it from the board. If I'm not mistaken chip is also in the LH module.

Not because of no FOB but because no key period.

 

[JRVAULTS]

It's been a while since I have seen my friend and the car which is why I called him on the phone about it so don't quote me on the 92 year. You say no chips in 92...then it's a 93...

 

[gsxr]

It's been a while since I have seen my friend and the car which is why I called him on the phone about it so don't quote me on the 92 year. You say no chips in 92...then it's a 93...

The engine photos show M119 CIS-E... that was only used in 1990-1992 500SL (129.066 chassis), no other years, no other models. And that chassis doesn't have the chip in the key fob. The IR key fob was only for remote lock/unlock. Chips weren't integrated into the key fobs until 1996 USA model year.

HOWEVER if you have NO KEY AT ALL, the ignition switch isn't turning on to energize either the ignition system or fuel system! You need to get a key for this, or you will have to manually bypass the ignition switch to get power to the fuel pumps and power to the EZL (ignition).

 

[JRVAULTS]

How do you bypass it?

 

[JRVAULTS]

Or did Gerry already explain how to bypass?

 

[JRVAULTS]

I concur, there is zero antitheft capability (save for the factory alarm) that is in a 1992 500SL. And this is simple to completely disconnect, just by unplugging a plug from the alarm module, if you want to.

This is a KE-Jetronic engine, so you should ensure that you have fuel flow to the fuel distributor via the fuel pumps. You can check this by jumpering the fuel pump relay sockets that control power to the fuel pumps, and then cracking a couple of individual fuel lines going into the top of the fuel distributor (just crack them, don't dramatically loosen them) and see if any fuel drops leak out.

If you have fuel, then you want to check spark per the two coils and twin distributors.

You should also easily be able to hot-jump the starter with a bridge wire -- no key should be required.

"Simple to completely disconnect, just by unplugging a plug from the alarm module"
What plug?

 

[gsxr]

How do you bypass it?

You have to figure out what wires power the EZL and manually connect +12v to those... same thing for the fuel pumps, but the fuel pumps may be easier. Since this is an R129, I don't have any tips, I've never owned one - sorry!

 

[gsxr]

"Simple to completely disconnect, just by unplugging a plug from the alarm module"
What plug?

He's talking about disconnecting the alarm system, which can prevent the starter from engaging if you use the key in the ignition (if the R129 had starter locking back in 1992 - not sure about that). Since you don't have a key, the alarm doesn't matter, disconnecting the alarm won't change anything.

 

[JRVAULTS]

Not having the key is preventing the plugs from getting spark...how can I bypass that?

 

[gsxr]

Not having the key is preventing the plugs from getting spark...how can I bypass that?

This is the hard part... no easy solution. You'll need to find a wiring diagram for the EZL, figure out which wire (or wires) normally provide power to the EZL from the ignition switch, and then splice into the harness.

Just curious, why get the engine running if you can't drive the car or turn the steering wheel...?

 

[JRVAULTS]

This is the hard part... no easy solution. You'll need to find a wiring diagram for the EZL, figure out which wire (or wires) normally provide power to the EZL from the ignition switch, and then splice into the harness.

Just curious, why get the engine running if you can't drive the car or turn the steering wheel...?

Who said you can't turn the steering wheel? The whole ignition has been torn out.

 

[JRVAULTS]

Who said you can't turn the steering wheel? The whole ignition has been torn out.

We originally were taking parts from this one for friends good one..same color, year, both convertibles....then the good one got totalled and towed to the location of the parts car...now we have title for parts car and we want it to run...just don't have key...ignition was already torn out when we got to it.

 

[gerryvz]

Have you checked with the good and highly knowledgeable people over at Benzworld? They have an excellent R129 forum that may be more helpful and more specific than folks here, given this is a W124-focused forum. Benzworld is the leading MB forum on the internet and has an extremely high success rate at helping folks solve difficult problems.