[Benz-there-done-that]

***Update!!!!!!!!***** In one last attempt today I disconnected the battery for a few hours, unplugged the aftermarket GPS module from the OBDII connector and rechecked all fuses.... I found one fuse that I overlooked in the fuse panel in the trunk that was missing and another was in the vacant spot and not in the right slot (#1 was missing & I think #3 was plugged into the vacant #4 slot.) Anyway after I reconnected the battery she fired right up!!!! Sorry Mr. Mechanic, no $4800.00 for you this week... AC blower still isn't working, and the buzzing in the dome light is still present, need to research these now but progress is being made!

I think the GPS device caused some electrical issues and the previous owner pulled fuses to make things stop buzzing, battery draining, etc. or whatever, and then the fuses not being present in the right slots caused the no start. **********

Hello All,

New to the forum and seeking advice and guidance on a non-start issue.

Brief summary:
- I am now a new owner of a non starting 1996 S500 4 door, automatic trans (was starting and running great 2 weeks ago), now it only briefly starts for half a second then dies like the fuel and /or spark is cut off. Does not get to idle, it barely ignites. Can get a quick "half rev" in if pedal movement is timed perfect (will not help I know, but just to give you an idea there is fuel and spark for a very brief time period)

- A GPS tracking device (Audiovox Car Connection) was installed into the OBDII connector by previous owner

- Car started and ran fine after it was installed. GPS device never worked properly I am told.

- Electrical Gremlins hitched a ride soon after:

-AC blower wouldn’t shut off even after key was removed, Fuse was removed to stop the blower from draining battery.

-Buzzing noise by the interior dome lights (but would stop after timed shutdown of all electrical components).

- all this and monkeying with fuses and then the car wouldn't start anymore, Car was jumped off prior to all of this several times and also tried jumping after these events (reversed jump or over voltage by jumping is not out of the question, but all fuses have been checked in front and rear panels and in main ECU, all appear ok and all fuse are back in)

- Car was taken to local shop and diagnosed as needing a PCM Module, and basic Module + programming with a quote of $4800.00 (does this sound right???), previous owner gave up and was going to junk it. Now its my project!

I took the battery out and fully charged it for 6 hours, this would have rest the ECU and it had full voltage, still no start. Looking for advice on what to do next, I have not pulled the codes personally as I do not have a Scanner.

Should I buy a scanner first and pull the codes myself?

Are the ECU’s plug and play where I can just buy a used one and swap it out?

The battery has been connected and disconnected several times, could this be a security/immobilizer issue or something with the Key?

Looking for advice and guidance on the best (and cheapest) way to proceed. Was hoping it would be something small and easy to fix but with all the electronics on this car it might get real pricey real fast….

 

[napaAl]

Yes, they are expensive to bring back from neglect, but worth it in the long run. Sounds like undoing the electronic add ons would be a good start. Good luck.

 

[Benz-there-done-that]

Yes, they are expensive to bring back from neglect, but worth it in the long run. Sounds like undoing the electronic add ons would be a good start. Good luck.

yep took the GPS out already, still no go.

Wondering if maybe it could be a bad key (no spare ) , the button doesn't unlock the doors but I am pretty sure he told me it didnt unlock the doors when it was running either... more searching and REsearching!

The green and red leds do nothing in the rearview mirror... I never saw them working properly so do not know what the normal function would be.... Can someone shed some light on this?

 

[Merc-S600]

Hi & Welcome to Benzworld
Is the petrol pump working ,under the rear drivers side ( right hand drive car ) ,you should hear a buzzing sound for a few seconds just before you crank the engine,if you don't hear it ,your petrol pump is not working ,how can the car start without petrol ,the way you describe it ,it certainly sounds like petrol starvation .
I think your mechanic there is a bit to expensive ,and not just a bit .... .:thumbsup:

Take a look at these & tell me how do they actually justify the price they gave you ,they wouldn't be for sale if they would'nt be compatible with other S500's,right!!!!,they must have judged you as a chicken that's why the high price ,lol .
http://www.ebay.com.au/sch/i.html?_...+&_nkw=Mercedes-Benz+W140+PCM+Module&_sacat=0

 

[Benz-there-done-that]

Hi & Welcome to Benzworld
Is the petrol pump working ,under the rear drivers side ( right hand drive car ) ,you should hear a buzzing sound for a few seconds just before you crank the engine,if you don't hear it ,your petrol pump is not working ,how can the car start without petrol ,the way you describe it ,it certainly sounds like petrol starvation .
I think your mechanic there is a bit to expensive ,and not just a bit .... .:thumbsup:

Take a look at these & tell me how do they actually justify the price they gave you ,they wouldn't be for sale if they would'nt be compatible with other S500's,right!!!!,they must have judged you as a chicken that's why the high price ,lol .
Mercedes-Benz W140 PCM Module | eBay

Thanks for the welcome Merc!

I'll check tomorrow to see if the pump sounds like it is coming on or not, also might check the rail to see if it is pressurized. I think it is, if it were not getting any fuel it wouldn't ignite at all, but it does and then dies quickly. I can even get a "half rev" if I push the pedal and time it right... its either electrical (ecu, relay, etc) or anti theft/ key related I am afraid.

And no, I think the mechanic is insane. To be clear it is not my mechanic, previous owner got a quote, maybe the mechanic really did not want to mess with it...

 

[Merc-S600]

Mmh ,if the car briefly starts & you can rev it once but any attempt after that ,that the car starts & then instantly dies ,that is a petrol supply problem but if like you say it starts & you can rev it every time then it is not fuel related ,if it was the petrol pump then the car still would start sort of but only with the fumes inside the petrol line ,you wouldn't be able to rev it or anything ,it dies straight away .
I think you have an Alarm issue there like a cut off switch somewhere that is malfunctioning,could it be the imobiliser? . :thumbsup:

 

[ianrandom]

I just stumbled on this thread and thought it sounds like a problem I had recently. Such a different beast though, it was on my w126.
It did exactly the same thing one day. I do a lot of my own work but couldn't figure this one out, the starting and then cutting off straightaway, the same every time.
Had to have it recovered and it was found to be the fuel injection ecu. In fact the garage unplugged this box and the car ran fine in purely mechanical mode only without cold start and wot enrichment etc. I did a road trip in it then with no problems.
So as soon as this ecu was called upon, it cut the fuel, effectively, because it was fried.

I had probably reconnected the battery with the ignition key turned and it had fried this ecu. £30 and I had a used one, car was back to normal.

Just thought I'd put it out there for thought. Hope you get it sorted.

 

[Benz-there-done-that]

I just stumbled on this thread and thought it sounds like a problem I had recently. Such a different beast though, it was on my w126.
It did exactly the same thing one day. I do a lot of my own work but couldn't figure this one out, the starting and then cutting off straightaway, the same every time.
Had to have it recovered and it was found to be the fuel injection ecu. In fact the garage unplugged this box and the car ran fine in purely mechanical mode only without cold start and wot enrichment etc. I did a road trip in it then with no problems.
So as soon as this ecu was called upon, it cut the fuel, effectively, because it was fried.

I had probably reconnected the battery with the ignition key turned and it had fried this ecu. £30 and I had a used one, car was back to normal.

Just thought I'd put it out there for thought. Hope you get it sorted.

Thanks so much for the suggestion! At this point I cannot rule anything out. My next step is to eliminate the key as a source of the problem. Called Mercedes dealership and there is a 20$ key option without remote but supposedly it has the chip to start the car. Once the key is eliminated as a problem source I will move on to checking the different ECU's (specifically what you mention first).

Will update as I know more, thanks again!

 

[Benz-there-done-that]

***Update!!!!!!!!***** In one last attempt today I disconnected the battery for a few hours, unplugged the aftermarket GPS module from the OBDII connector and rechecked all fuses.... I found one fuse that I overlooked in the fuse panel in the trunk that was missing and another was in the vacant spot and not in the right slot (#1 was missing & I think #3 was plugged into the vacant #4 slot.) Anyway after I reconnected the battery she fired right up!!!! Sorry Mr. Mechanic, no $4800.00 for you this week... AC blower still isn't working, and the buzzing in the dome light is still present, need to research these now but progress is being made!

I think the GPS device caused some electrical issues and the previous owner pulled fuses to make things stop buzzing, battery draining, etc. or whatever, and then the fuses not being present in the right slots caused the no start.

 

[napaAl]

Have you checked the cabin temp sensor that's situated up near the dome light?

A visual inspection of the blower motor under the hood is a good place to start for the fan problem.

 

[MAVA]

Glad you got your car rolling with a 20 dollar replacement key...

Again, welcome to the forum...What did you pay for your beast? Post some pictures...

I have a S320 which is perfect, and $1000 dollar beast that had every electronic item shot, but short of having what your have, and I have nursed it back to health..

The fan and the dome will be a easy fix... But first before you get to joyful with your W140 and start driving it.. Change these two like in a new york second!!!

The "Killer Plastic Tee", buy a fresh one from the Mercedes Dealer-No aftermarket, ebay deals, craigslist, or used ones

http://www.benzworld.org/forums/w14...-under-hood-really-devil.html?highlight=devil

Get a new hose:

http://www.benzworld.org/forums/w140-s-class/1719760-another-coolant-fitting-breaks.html

While your add-it, change your thermostat...

Now, your Fan

9 times out of 10 it is the regulator, but before you buy a clone or an expensive BEHR qualify that your climate control module is putting out the correct control voltage. You will need a volt meter. Disconnect the signal wires(or all of them from the regulator). Measure the 0 to 10v(or so) from the climate control module. See post 36, but this whole thread should help.

http://www.benzworld.org/forums/w14...-blowser-regulator-replacement-diagnosis.html

If you find out your regulator is shot, clean the old white paste with a solvent from the fan(clean it very well!!) Use American made paste not the cheap Chinese stuff that is put on Computer Processors...Do not goop-it on. It should look Semi-transparent on both mating surfaces, and even coat!!! This paste is the key to the regulator longevity. The paste to provide thermal conductivity-too much or none at all does not promote thermal conductivity of the regulator to the metal on the fan unit...

Here is the paste:

New Aavid Thermalcote 249 Thermal Joint Compound CPU Heat Sink Paste 28g 1oz | eBay

The stuff made by Aavid is excellent quality, just squeeze out the clear liquid out(do not use it). You want the thick white stuff in the tube...All you need is one tube

I could not tell you anything about the dome light, nor do I know where the circuit is at, but I think the drive transistor or the relay on the board is shot...

While you are finding all this stuff, download the S600 service manual before it disappears. A lot of the parts will be the same.

http://www.benzworld.org/forums/w140-s-class/1766394-merc-s600-600sel-workshop-manual-here.html

Enjoy your car and welcome to the forum...

MArtin

 

[bnZE430/1999]

***Update!!!!!!!!***** In one last attempt today I disconnected the battery for a few hours, unplugged the aftermarket GPS module from the OBDII connector and rechecked all fuses.... I found one fuse that I overlooked in the fuse panel in the trunk that was missing and another was in the vacant spot and not in the right slot (#1 was missing & I think #3 was plugged into the vacant #4 slot.) Anyway after I reconnected the battery she fired right up!!!! Sorry Mr. Mechanic, no $4800.00 for you this week... AC blower still isn't working, and the buzzing in the dome light is still present, need to research these now but progress is being made!

I think the GPS device caused some electrical issues and the previous owner pulled fuses to make things stop buzzing, battery draining, etc. or whatever, and then the fuses not being present in the right slots caused the no start.

That buzzing is something Im dealing with right now too. Its a little fan for the climate control system behind the slots by the sunroof control. Some have had luck with cleaning them. I remember installing another one after the buzzing wouldn't stop. It lasted 2 years, now the buzzing is back. Glad you are making progress.

 

[Bobolinski]

Maybe ignition switch? Once I let go of key the engine would die. If I did not let key back all the way car would stay running....just throwing darts

 

[Benz-there-done-that]

Glad you got your car rolling with a 20 dollar replacement key...

Again, welcome to the forum...What did you pay for your beast? Post some pictures...

I have a S320 which is perfect, and $1000 dollar beast that had every electronic item shot, but short of having what your have, and I have nursed it back to health..

The fan and the dome will be a easy fix... But first before you get to joyful with your W140 and start driving it.. Change these two like in a new york second!!!

The "Killer Plastic Tee", buy a fresh one from the Mercedes Dealer-No aftermarket, ebay deals, craigslist, or used ones

http://www.benzworld.org/forums/w14...-under-hood-really-devil.html?highlight=devil

Get a new hose:

http://www.benzworld.org/forums/w140-s-class/1719760-another-coolant-fitting-breaks.html

While your add-it, change your thermostat...

Now, your Fan

9 times out of 10 it is the regulator, but before you buy a clone or an expensive BEHR qualify that your climate control module is putting out the correct control voltage. You will need a volt meter. Disconnect the signal wires(or all of them from the regulator). Measure the 0 to 10v(or so) from the climate control module. See post 36, but this whole thread should help.

http://www.benzworld.org/forums/w14...-blowser-regulator-replacement-diagnosis.html

If you find out your regulator is shot, clean the old white paste with a solvent from the fan(clean it very well!!) Use American made paste not the cheap Chinese stuff that is put on Computer Processors...Do not goop-it on. It should look Semi-transparent on both mating surfaces, and even coat!!! This paste is the key to the regulator longevity. The paste to provide thermal conductivity-too much or none at all does not promote thermal conductivity of the regulator to the metal on the fan unit...

Here is the paste:

New Aavid Thermalcote 249 Thermal Joint Compound CPU Heat Sink Paste 28g 1oz | eBay

The stuff made by Aavid is excellent quality, just squeeze out the clear liquid out(do not use it). You want the thick white stuff in the tube...All you need is one tube

I could not tell you anything about the dome light, nor do I know where the circuit is at, but I think the drive transistor or the relay on the board is shot...

While you are finding all this stuff, download the S600 service manual before it disappears. A lot of the parts will be the same.

http://www.benzworld.org/forums/w140-s-class/1766394-merc-s600-600sel-workshop-manual-here.html

Enjoy your car and welcome to the forum...

MArtin

Actually the key is just a bonus... I used the old key to start it after sorting out the missing and misplaced fuses.

I actually saved this car from the junkyard believe it or not. Didn't pay a dime for it, Previous owner is an older family member who took it into the shop and was told $4800 to fix it. He was just going to scrap it and I asked if i could look at it before junking it (thought I would at least part it out if I couldn't fix it) .

Will post some pictures later on, its not perfect but very nice for free

Thank you very much for taking the time to write out all the tips and advice. I will heed the warnings and replace the TT fitting, thermostat, and the hose.

Will keep you posted on how the repairs and diagnosis goes!

 

[Benz-there-done-that]

That buzzing is something Im dealing with right now too. Its a little fan for the climate control system behind the slots by the sunroof control. Some have had luck with cleaning them. I remember installing another one after the buzzing wouldn't stop. It lasted 2 years, now the buzzing is back. Glad you are making progress.

Ah ha! that's what that noise is.... Thanks for the enlightenment! I'll try cleaning it first.

 

[MAVA]

Gotta love free-99...

Yep, got to love free-99. A W140 is a W140...My 1000 dollar beater probably looks worse than yours.

MArtin

 

[Merc-S600]

***Update!!!!!!!!***** In one last attempt today I disconnected the battery for a few hours, unplugged the aftermarket GPS module from the OBDII connector and rechecked all fuses.... I found one fuse that I overlooked in the fuse panel in the trunk that was missing and another was in the vacant spot and not in the right slot (#1 was missing & I think #3 was plugged into the vacant #4 slot.) Anyway after I reconnected the battery she fired right up!!!! Sorry Mr. Mechanic, no $4800.00 for you this week... AC blower still isn't working, and the buzzing in the dome light is still present, need to research these now but progress is being made!

I think the GPS device caused some electrical issues and the previous owner pulled fuses to make things stop buzzing, battery draining, etc. or whatever, and then the fuses not being present in the right slots caused the no start.

Just noticed the update here Benz-there-done-that ,I'm so happy for you that you got it fixed with just the fuse ,what did the owner that gave you the car when you told him do ,did he ask to give the car back or any weird regrets , impressions ? ,i can almost picture the look that he must have had on his face ,lol.
One of those perfect examples not to always listen to the super high prices the mechanics give/shoot out . :thumbsup:

 

[86560sel]

Hey guys,

I don't mean to hi-jack this thread, but is this also the paste I should use under my replacement EZL module? I was thinking about going to Radio Shack and getting some, but it looks like this may be best? What is the best way to remove the old hardened paste from the replacement module and car body? Simply scrape it off?

Thanks!

Here is the paste:

New Aavid Thermalcote 249 Thermal Joint Compound CPU Heat Sink Paste 28g 1oz | eBay

The stuff made by Aavid is excellent quality, just squeeze out the clear liquid out(do not use it). You want the thick white stuff in the tube...All you need is one tube

MArtin