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Mercedes Benz 180 C 1.8 1995 - Non starter - Fixed #

Posted by Paul Neasham on February 25, 2010, 6:46 pm

Year of Manufacture *: 1995
Engine Code or CC *: 1800 cc m111 421
( Optional ) Scanner Used: modis

Car is a non starter. On initial key on there is no fuel pump buzz and on cranking there is no spark,injector duration or fuel pump running. The immobilizer shows its correct sequence when arming and disarming.modis shows no communication.ecu has the correct lives and earths according to autodata. Isuspect the immobilizer is not making the ecu come alive but am unsure how it works or where the immobilizer is in the car.on one wiring diagram it shows an input from a "key transponder"on to term b12 of the ecu but that is the only reference to an immobilizer i have found.anyone know of a way to input a signal on to b12 to fool the ecu if so what kind of signal.

Any help gratefully recieved

Re: mercedes 180 c non starter

Posted by andyhyoung <iframe src='https://members5.boardhost.com/ukautotalk4/info/user=UKAT5148' width='330' height='300' border=0 style='border:none;'> on February 25, 2010, 7:41 pm, in reply to "mercedes 180 c non starter"
Andrew Young

This car may just be an early enough model to have an add-on Merc/scorpion immobiliser system.Lift the carpet and false floor on the passenger side front footwell.There may be an immobiliser box linked in to the remote key entry system.Untape the harness and should be able to link out the immob circuit.hth

Re: mercedes 180 c non starter

Posted by paul neasham <iframe src='https://members5.boardhost.com/ukautotalk4/info/user=UKAT1202' width='330' height='300' border=0 style='border:none;'> on February 26, 2010, 6:22 pm, in reply to "Re: mercedes 180 c non starter"
Paul Neasham

andy i think you could be spot on .we have lifted the carpet etc and there are 2boxes one- from part no- is the remote keyless entry module the other has a merc part no but means nothing to the parts dept(Q350 010 21).it has approx 24 wires in 2 multiplugs all different colours.any idea how it was wired to immobilize.would it physically switch 3 or more cicuits or would it do it through the engine pcm.there is a siren in the engine bay and 2 wires to the front panel possibly for bonnet switch .the rest of the wires seem to go forward and back but remain in the cabin and difficult to trace behind the dash.any clues to my nextmove.thanks in advance regards paul

Re: mercedes 180 c non starter

Posted by Tony Sefton <iframe src='https://members5.boardhost.com/ukautotalk4/info/user=UKAT5581' width='330' height='300' border=0 style='border:none;'> on February 26, 2010, 7:15 pm, in reply to "Re: mercedes 180 c non starter"
Tony Sefton

Hasn't it just got multiplugs that you can unplug and reconnect to their original sockets. ??

I am sure that the ones that we have done have been like that.

H.T.H. Tony.

Re: mercedes 180 c non starter

Posted by Shaun Dale <iframe src='https://members5.boardhost.com/ukautotalk4/info/user=UKAT2719' width='330' height='300' border=0 style='border:none;'> on February 26, 2010, 7:21 pm, in reply to "Re: mercedes 180 c non starter"
Shaun Dale

Hi Paul,
Long time since I have done one of these, but from memory there is only one circuit of immobilisation. I seem to have a vague memory of green/brown or brown/green wires on the Merc loom.
HTH Shaun

Re: mercedes 180 c non starter

Posted by andyhyoung <iframe src='https://members5.boardhost.com/ukautotalk4/info/user=UKAT5148' width='330' height='300' border=0 style='border:none;'> on February 26, 2010, 7:26 pm, in reply to "Re: mercedes 180 c non starter"
Andrew Young

Ditto;If I recall it only immobilises the fuel pump relay.Take a look under the plastic cover ,in engine bay,passenger side.There should be some added in wiring from the alarm module.hth

Re: mercedes 180 c non starter

Posted by Andrew Ruellan <iframe src='https://members5.boardhost.com/ukautotalk4/info/user=UKAT5382' width='330' height='300' border=0 style='border:none;'> on February 28, 2010, 4:21 pm, in reply to "Re: mercedes 180 c non starter"

Hello Paul,

It sounds like you are on the right track.

Mercedes fitted an alarm to the Central locking/immobilizer system on this car to up the Thatchams security rating.

The alarm system interrupts the C Can at the central locking unit (IFZ module). This stops the engine starting as it does not see a valid unlock code from the IFZ module even though the correct key was used.This unit is under the drives foot plate next to the alarm box.

On the unit there are 2 connectors, one of them only has 2 wires. These are the C Can wires, Green and green/white. One of these wires will have been cut and the alarm unit joined into the break. All you have to do is re-make the straight through connection to the cut wire.

Please post your findings

Regards

Andrew Ruellan

Re: mercedes 180 c non starter

Posted by paul neasham <iframe src='https://members5.boardhost.com/ukautotalk4/info/user=UKAT1202' width='330' height='300' border=0 style='border:none;'> on February 28, 2010, 5:39 pm, in reply to "Re: mercedes 180 c non starter"
Paul Neasham

it never ceases to amaze me the knowledge and experience on this site.yesterday i stripped out the whole merc/aftermarket alarm system as i was unsure how many circuits were immobilized.turned out to be just one circuit on (youve guessed) it the control box multiplug you describe .i have rejoined the connection although i did not realise it was a can line the wires werent a twisted pair.scoping that connection at the ecu i now have a continuous square wave pattern @5v on term b12 with key on .this must be the signal to make it come alive alas no we still have no start.i now seem to have lost a good signal from the crank sensor so will check that out further tomorrow.i realize that if the crank signal is not there the engine wont start but does it affect ignition fuel pump and injector circuits or just ignition?also still have no comms with modis could this have anything to do with the can line you describe?many thanks again paul

Re: mercedes 180 c non starter

Posted by Andrew Ruellan <iframe src='https://members5.boardhost.com/ukautotalk4/info/user=UKAT5382' width='330' height='300' border=0 style='border:none;'> on February 28, 2010, 6:07 pm, in reply to "Re: mercedes 180 c non starter"

Hello Paul,

Sorry for the late reply, but I do not get a chance to go on here much.

Have you locked/unlocked the car since you have made the repair ?

The control unit is hard wired to the diagnostic connector. You can get flash codes from it with a LED and a switch (or a power probe if you are carefull). the info was in a "Fault code" book, Either Autodata or the earlier Peter Combs one.

If you still have problems email me your phone number and I will take you through a few tests. If you could write these up after wards it will be in the archives for everyone...... and same me a bit of time.

regards

Andrew Ruellan

Fixed #

Posted by Paul Neasham on March 19, 2010, 8:28 pm, in reply to "Re: mercedes 180 c non starter"
Message modified by board administrator March 22, 2010, 2:54 pm

apologies for length of time between last post and now but we had all but condemned the ecu but did not have the bottle or authorisation to spend £1503.00 on a new ecu and then according to the dealer stores have them code it to the car .after a bit of sound advise from andrew ruellan and some patience we aquired one from ebay for £150.00.it arrived today and the car fired up first time after fitting with no coding.my sincere thanks to all who took the time to offer advice it is truly appreciated .special thanks to andrew who took time out to ring me and email me with circuit diagrams.we have certainly learned much from this and do not worry so much when condemming an ecu providing everything else checks out .my thanks again

Fixed #

Posted by Andrew Ruellan on March 21, 2010, 11:58 am, in reply to "Re: mercedes 180 c non starter FIX"
Message modified by board administrator March 22, 2010, 2:55 pm

Good Morning Paul,

Thanks for your kind words. Glad to see that you got it fixed. As you know, Mercedes WIS did not have a actual line diagram of this system. It did have a few pages with the pin numbers and actual values of the wires.

From experience we knew that another ECU of the same number would just plug and play without the need for coding.

The wires I referred to as CAN are infact just data lines from the IFZ to the PMS (engine ECU)

Thanks for posting the fix.

Regards

Andrew Ruellan

Fixed #

Posted by Michael McDowell on March 21, 2010, 5:34 pm, in reply to "Re: mercedes 180 c non starter FIX"
Message modified by board administrator March 22, 2010, 2:55 pm

Hi Paul.I have had the same degree of help off andrew on several occasions which shows the type of person he is on several he has phoned me back to make sure the job was fixed that is more than help,its a pity some others on this forum would rather slag him off than take on board what he is saying sorry if i hi-jacked your post just felt it needed saying. Michael McDowell

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