W140 immobiliser problems

[oilydave]

Hi - I'm wondering if anyone can help. I've looked at other similar threads but still can't figure what's wrong.

Car is 1996 S500 N reg.

• Remote key works ok, has new batteries and opens and closes the car on the remote as normal.
• Green light on the mirror flashes when I open the car (as normal)
• I put the key in the ignition and start the car as normal.
• (no flashing green light)
• Car fires up for a very short time (a second?) and then stops.
• Green light on the mirror flashes continuously.

The car has been standing for a few weeks and it's been raining constantly for 48 hours (normal crap British weather) but it's not as if the engine isn't firing - it starts with the normal vrooom ... then stops.

The switch on the gear shift is sometimes a bit dicky if the lever isn't perfectly in the P position but under those circumstances the car wouldn't turn over at all.

I'm currently making sure that the battery has lots of charge in it (it's taking a few amps) and have disconnected it, left it 10 minutes and reconnected it.
I have put new batteries in the remote.

Any ideas, anyone?

 

[oilydave]

more info....

Having tried again....

If I open the doors on the remote fob (green light flashes on the door) then sit in the drivers seat and turn the key to position 2 (not starting the car) then the green light starts flashing.

Any ideas, anyone?

 

[television]

Not easy this one, my car is the later version and not the same, I was thinking the UK fitted alarm but the indicators would flash if the alarm was un setting

 

[oilydave]

I found this thread

http://forums.mercedesclub.org.uk/showthread.php?t=106184&highlight=yellow/red+black/purple&page=9

I'm wondering if it's a similar system. I think that the lack of the usual red light in the door when it's locked might be significant.

But I can't see why it'd fire at all if the fuel pump relay was disabled.

I'll keep looking or see if anyone has any ideas and can perhaps guide me on how to bypass the immobiliser; otherwise the car (much as I love it) will just have to go to the scrapyard - I'm not throwing hundreds of pounds at a potential money pit

 

[television]

Not the K38, thats for sure as only a starter lock out

I know the mirrors can give problems.

I am guessing now, can you start the car without getting in, I am thinking of a motion sensor problem, but I could be way out.

When the car was made there were programmers that could set and check the system

 

[oilydave]

Hi TV

Thanks for the reply. I'm not 100% sure what you mean start the car without getting in. But if that's some sort of facility to start it from the remote, then no.

It's the system where you can open the drivers window by keeping your finger on the remote (whilst unlocking the car) and close the window whilst locking it.

The significant change is that the red light on the drivers door always flashed when the car was locked before, and now it doesn't.

Normally, when I leave the car open for a while and then try to start it, the same thing happens as is happening now. I usually then lock and unlock the car on the remote and it starts.

Oddly, just opening the drivers door on the key did not activate the central locking system - but to be honest I've never used the key so don't know if this is normal.

 

[oilydave]

Ah, hang on I think I've just twigged what you mean. OK I can block off any motion sensors and see if that helps, but it just feels like the immobiliser isn't deactivating.

I will call round a few auto electricians and see if anyone knows how to disable the alarm / immobiliser.

 

[television]

Ah, hang on I think I've just twigged what you mean. OK I can block off any motion sensors and see if that helps, but it just feels like the immobiliser isn't deactivating.

I will call round a few auto electricians and see if anyone knows how to disable the alarm / immobiliser.

To take out the UK fitted alarm, you just join up the wires, colour to colour and that is it

 

[oilydave]

ok thanks TV

So is the immobiliser the same unit as the alarm?
Is that the ATA module? Where will I find it?
What do you mean by colour to colour?

cheers

Dave

 

[oilydave]

To take out the UK fitted alarm, you just join up the wires, colour to colour and that is it

Does this look the same as the UK system, TV?

http://www.k6jrf.com/MB_ATA.html

cheers

Dave

 

[oilydave]

Diagnostics

To take out the UK fitted alarm, you just join up the wires, colour to colour and that is it

Now a little more light?

Diagnostics codes in ME1RE system read as follows:

P1570 Fault in DAS to Engine Control Module N3/10. This is both a current and stored fault.

In "Current values" I see:
55 ME1RE Start Enable set to NO
56 Car Locked with DAS YES
66 Starting Operations if engine control module not interlocked number 0

What on earth does that mean?

cheers

Dave

 

[oilydave]

To take out the UK fitted alarm, you just join up the wires, colour to colour and that is it

Having done a bit of research...

I believe that my car has DAS2. It's build date November 1995.

I found the italicised passage below on the web. So the DAS signal comes from my RCL (remote central locking?) Control unit. I think this is 140 820 00 26.

Note the bit about the ME-SFI unit making "the fuel injection system inoperative". Does this mean via turning off the fuel pump, I wonder?

Looking at the Star Classic service CD for the W140, the two wires to the fuel pump relay coil are as follows:

(1) From Pin #24 on N3/10 (which I assume is the ECU) grey/blu/white wire to connector x35/59 and then brown/blue to the relay contact 86
(2) From relay contact 85 there's a red/blue wire to "circuit 87 M1E connector sleeve".

What the hell is "circuit 87"? Why can't they call this "circuit braking" or "circuit toaster" or something sensible? Does anyone know what "circuit 87" is? I can find no sensible reference to it.

My plan is to try and rig a 12 volt feed to the fuel pump when the ignition is on and therefore to try and bypass the immobiliser that way. Does that make sense? anyone?




Note regarding drive authorization system (DAS) stage 2 and stage X:
Vehicles with ME-SFI are equipped with a drive authorization system (DAS).
The activation/deactivation of the drive authorization system takes place from
the RCL control module (stage 2) or from the DAS control module (stage X)
via CAN data bus to the engine contro9l module (ME-SFI). After activating
the drive authorization system, the engine control module renders the fuel
injection system inoperative.
On vehicles till 05/96 a drive authorization system stage 2 is installed. This
drive authorization system can only be activated/deactivated with the IR
transmitter or the master key.
On vehicles as of 06/96 a drive authorization system stage X is installed. The
activation or deactivation is accomplished with transponder technology via
the ignition key. As soon as the ignition key is turned in the steering lock the
DAS control module receives a signal and the fuel injection system is made
operative via the CAN data bus.
The engine control module and the RCL or the DAS control module are
locked" to one another through identification codes. The identification
codes can not be erased (see HHT nominal values DAS", menu
selection 3/7).
Therefore, swapping the engine and RCL or DAS control modules from
one vehicle to another is not possible!

 

[television]

Circuit 87 is the plus voltage for the engine components, the fuel pump is wired via the fuel pump rely, you cannot let it run all the time

 

[oilydave]

Circuit 87 is the plus voltage for the engine components, the fuel pump is wired via the fuel pump rely, you cannot let it run all the time

I tried shorting out the pins of the fuel pump relay so that the power went to the fuel pump, but to no avail.

I have however noticed a few things:

The red light no longer flashes on the door handle when the car is locked.
Opening the drivers door with the key doesn't activate the central locking, though all doors and boot open with the remote

I suspect that the RCL unit is defective as in this car it's that unit that sends the drive authorisation signal to the ECU and the code reader tells me that the ECU is saying that DAS is locked. And of course the stupid RCL is one-time flash coded to the ECU

Mercedes tell me that the unit is £390+vat.

No mobile auto electrician wants the business - meaning that (a) they're either all richer than Warren Buffet and don't need the business (b) they're too lazy to drive out of the city or (c) this problem is unfixable.

I expect that by the time it's been diagnosed and a new unit fitted I'll be looking at £1000. I will open up the RCL unit and see if there are any physical relays which may have jammed, but I doubt it since the signal is sent via the CAN bus.

I could try and see if a specialist breaker has the right matching ECU and RCL units, but since DAS2 was only in production for a year or so it's a long shot.

 

[television]

In order to try and help find your way around, please use this site, the cars are unchanged till 96 and the engine fitted makes no difference.

The one thing that we have no info on is the UK fitted alarm/imobilizer

http://www.autolib.diakom.ru/CAR/Mercedes-Benz/1995/E320/SYSTEM WIRING DIAGRAMS/


Go to year, then model then diagrams

If I get a chance I will try and find more

 

[oilydave]

more info....

Hi Telly

I've been ridiculously busy in the intervening weeks, but came across this (see attachment). This was apparently notes from an MB training course for mechanics.

The UK alarm is apparently a Scorpion which explains a lot. I remember the 1986 VW Scirocco GTX that my wife had when I first met her (what a car that was, I so wish we'd kept it). That had a Scorpion alarm - OK no-one nicked the car but we could never get it to un-immobilise either.

When time permits I'll do some investigation on the car

cheers

The Oily One

 

[television]

Yes a Scorpian would explain it, at least you have the right info now. No info on Scorpians in WIS

 

[oilydave]

easy when you know how...

Well, that turned out to be easy in the end:

Snip the yellow/red and black/purple wires from the immobiliser. Join the "car" ends together. Voila. Turn the key and a most welcome V8 noise results.

 

[television]

Wonderful news and I have tagged the thread

 

[RafW]

easy when you know how...

Well, that turned out to be easy in the end:

Snip the yellow/red and black/purple wires from the immobiliser. Join the "car" ends together. Voila. Turn the key and a most welcome V8 noise results.

hi,

it looks like a have a same problem with my CL420 , remote opening doors Green light flash and then when I turn a key to a second position green and red flashing alternately.
New batteries , sync with a car but everytime I try to start flashing leds and won't start.

please explain me where these wires are located.

thank You for Your help.

Regards