2003 S500 will not start. Help!

[johnpdx]

I got this car from my friend. He took it to the dealership and they diagnostic that it need a Electronic Shifter Assy and need a brake switch.

I didn't replaced the shifter assy since it was the brake switch issue. The car started and drive with no problem until I was running a OBD2 scan while the engine was running and the engine cut off during the scan. I was able to start the car once for less than a minute before it cut off.

Current condition:

I can't get the OBD2 to communicate at all, I check the fuse for the diag port, getting no power.

I'm getting power signal from the EIS system to relay, I'm not getting ground signal from ECM to latch the relay. Bypass relay directly will turn the starter motor, no sparks.

I bought a matching ECM and swapped Immobilizer EEPROM. It still acting the same with the fan running when the key is in the start position.


I need some pointer to go from here. A starter / diagnostic port diagram would be great. It hard to troubleshoot this car when I can't scan it and with little diagram is a nightmare. Please assist if you can.

 

[Craiglxviii]

Do you have Star?

 

[alexanderfoti]

Yes ideally star to check if you have start authorisation.

Although if you can turn the key and get the gear lever out of P you probably have start auth. You should always have power on the OBD port, so check no fuses have popped.

 

[johnpdx]

I'm new to Mercedes, I would like to have star software. How do I get one?

Anyways, the key turn with the current condition. I can get the shifter to release and change to neutral.

Relay checks:
Pin86: Power from Electronic Ignition Switch
Pin85: Ground from ME
Pin30: Constant 12V
Pin78: 12V to Starter

At the start position, I have NO ground signal from ME. I need a wiring diagram for the Diagnostic port, I can't communicate to even scan anything.

 

[Craiglxviii]

Star will set you back £600-900 at current rates.

You really need to get the car to a Star equipped garage and let the car itself tell you, via Star, what is wrong. You'll end up 20 years older with much less hair otherwise...

 

[johnpdx]

ECU REPLACEMENT

I found a complete replacement for the ECU with shifter, ECU, ignition and key.

Does the ECU part # have to match with the original one? My current part # ENGINE COMPUTER 113 153 27 79.

The package deal parts I'm looking at has a engine computer # 113 153 44 79. It's the correct year and model. If it doesn't matter then I will order it.

Thanks

 

[Craiglxviii]

You're completely not listening about getting the car on a diagnostics rig, are you?

Don't throw parts at the car to fix the problem. Get the car's very sophisticated and intelligent diagnostics tell you what the problem is first.

 

[johnpdx]

ECU REPLACEMENT

I understand the complication of this car. I have work with german cars for many of years and understand the technical aspect of the system. I have OTC pegisys scanner that can scan individual module. I have gone through every fuse in this car and verify connection from the K-line to ECM. I already had the dealer diagnose that the Electronic Shifter need replacing.

With any car, it hard to troubleshoot if you can't communicate with the ECU through the diagnostic port.

 

[Craiglxviii]

I understand the complication of this car. I have work with german cars for many of years and understand the technical aspect of the system. I have OTC pegisys scanner that can scan individual module. I have gone through every fuse in this car and verify connection from the K-line to ECM. I already had the dealer diagnose that the Electronic Shifter need replacing.

With any car, it hard to troubleshoot if you can't communicate with the ECU through the diagnostic port.

Ok. Regardless of all of that, do you have the diagnostic system that this car had designed for it?

The reason I ask is this. I have the coupe version of your exact car- my 215 it's a 2 door S500. The first time I took it anywhere for a diagnostic check I was told, "Ah, afraid your OBD2 socket is knackered. My kit can't even tell that your car has an engine!" This was, of course, utter bollocks. But the point is that unless you have Star or something designed to work with it (specifically the iCarsoft i980 or MB2) then you'll be lucky to get anything at all from the socket. And what you do get will be a mixture of generic codes and gibberish.

So I'll repeat my advice. Get the car onStar. At the very least you'll have access to a mechanic with knowledge of Star, and MBs- which have a different architecture to anything else, German or not btw- and experience of what to do to fix them. It'll cost £60 for a diagnostic session.

Ok, that's my input for this thread.

 

[johnpdx]

ECU REPLACEMENT

Understand your point. I was looking into getting the Carsoft scanner.

I was able to scan with the OTC scanner and matches with what the dealership quoted for. I try to scan it the second time after my repair while it was running and that when the engine shut off. I'm confident that the ECU is not communicating.

 

[triumphstag]

That's the thing though, as I understand your post, the car broke whilst you had your scanner plugged in. The likely answer is that your scanner upset something in the cars electronics that now needs to be reset.

You are spending lots of hours and money replacing parts that won't be cheap and hoping it works, possibly introducing additional problems as many of these parts will not be coded to your vehicle (did I read that you replaced parts of the ignition?)

Really, you need to get it on a Star system for a diagnostics session. That session may even be able to reset something that's sorts you out.

Keep changing bits without really knowing what the problem is will just make things worse and worse.

This is not meant to be a go at you, it is advice, these cars are not meant to be scanned by the standard scanners (well not to produce anything meaningful). A star session is really the best way forward, and for £60 you would likely have been back on the road by now.

 

[johnpdx]

Thanks you for the reply. What is a star session? How can it help me pinpoint the problems?

The scan must screw something up. I'm been searching and going to different forums. So many multiple angle to look at it. The problem is at the advance level and require the right tool. :idea:

 

[Craiglxviii]

Thanks you for the reply. What is a star session? How can it help me pinpoint the problems?

The scan must screw something up. I'm been searching and going to different forums. So many multiple angle to look at it. The problem is at the advance level and require the right tool. :idea:

Triumphstag just said what I did in different words.

Star is MBs own diagnostic software. It's a highly invasive, intelligent system that allows one to view, code in and out and do all sorts of funky things to almost everything on the car.

Right now you're in denial that the kit you have will work the way you think it will. It won't. You need MB specific diagnostic kit.

You need to ask the forum members for Star equipped garages in your area.

 

[triumphstag]

Triumphstag just said what I did in different words.

Star is MBs own diagnostic software. It's a highly invasive, intelligent system that allows one to view, code in and out and do all sorts of funky things to almost everything on the car.

Right now you're in denial that the kit you have will work the way you think it will. It won't. You need MB specific diagnostic kit.

You need to ask the forum members for Star equipped garages in your area.

Exactly. Much as I hated the response that "you have to get it on a star system" to most problems that I had when I got my R230, I now accept that it really is the answer.
Troubleshooting by replacing parts on these cars just does not work.

All you are doing is just making things worse for when you go finally admit defeat and have to take it in for the diagnostics session. And when they do scan it properly , it will likely find the original issue plus 15 more that you have now introduced by swapping parts.

I am a decent mechanic and have been pulling cars apart and putting them back together since I was about 10 years old and have rebuilt or restored dozens of cars. I very rarely used (or trusted) garages, but you cannot do that with these cars, whilst there are oily bits that you can do yourself, the rest of it is a computer on wheels and you do need someone with access and understanding of the software and how to program it.

Obviously your problem now is getting it to someone if you cannot start it. Are you in the AA/RAC with home-start?

If you let us know what area you are in, as Craig says someone will be able to recommend a place, maybe even a mobile specialist.

 

[daibevan]

Exactly. Much as I hated the response that "you have to get it on a star system" to most problems that I had when I got my R230, I now accept that it really is the answer.
Troubleshooting by replacing parts on these cars just does not work.

All you are doing is just making things worse for when you go finally admit defeat and have to take it in for the diagnostics session. And when they do scan it properly , it will likely find the original issue plus 15 more that you have now introduced by swapping parts.

I am a decent mechanic and have been pulling cars apart and putting them back together since I was about 10 years old and have rebuilt or restored dozens of cars. I very rarely used (or trusted) garages, but you cannot do that with these cars, whilst there are oily bits that you can do yourself, the rest of it is a computer on wheels and you do need someone with access and understanding of the software and how to program it.

Obviously your problem now is getting it to someone if you cannot start it. Are you in the AA/RAC with home-start?

If you let us know what area you are in, as Craig says someone will be able to recommend a place, maybe even a mobile specialist.

I also like to do everything myself, but this is the best advice.

 

[Submariner1]

In ABC language, trying to save you a shed load grief, not being rude.
Listen to Craig ... he has been through the mill!

I am a crap mechanic, challenge a lot of stuff on the net, until I am absolutely sure ... but I you need to get it on STAR , proper STAR ... only then will you know what to fix.

Eg my duff new battery generated 5, Yes 5 pages of faults... mainly low voltage issues. I could have spent £8000 on bits that had failed ... all for nothing. It was the battery.

The mobilo technician came back with a new battery, then ran a full battery test on that one. It passed . Then he ran the Star Initial Test again just to be sure what he was dealing with. Then cleared all the faults and ran it again. They came back as expected .. he then put in the new battery and ran the test again, then cleared down the codes, then ran it again ... this time they all disappeared.
Its a logical process.

Just swapping parts (that may even need being coded to the car ) could introduce a whole load of additionsl issues, snd cost you a fortune in diagnotic time all for nothing.

The big wake up call for you, should be it sounds like your ODBC reader COULD have screwed up the cars electronics!
Yet you persist in wanting to use it.
I would have my doubts with the MBII!

 

[Craiglxviii]

The first thing I was told when I got my i980 was, NEVER EVER start the car with it plugged in. The chance of it affecting something is infinitesimal but it's still there.

My CL500- again to remind you the same platform and powertrain and complexity as your S500, the only difference being the ICE databus and version of COMAND- generated 149(!) fault codes the first time it was plugged into Star. 149! The world fell out of my arse when I saw! Then, just like Sub, almost all of them disappeared when a new battery was installed. Undervoltage is a killer for W220 consumer modules. Once the battery drops below I think 11.4V you'll get all sorts of weird things happen, randomly and unpredictably too.

So. Star that car!

 

[johnpdx]

I think everybody has a valid point. These car are much more complicated then your average Joe technician can repair. The plan is to the get the car all button up and send it in to the dealership to identify the problem for me. It already been in the MB dealership before for diagnostic. I repaired that part, now there more issues from the scan. As a technician by trade, my job is to narrow down the problem. Time is not permitting.
I been getting information across multiple forums and checking troubleshooting suggestion since this is my first MB. It's not about accepting defeat, it about nearing the problem down as a technician. I have sent in car before to repair shop to help me down narrow the problem and then in turn I fixed it myself.

 

[johnpdx]

I think everybody has a valid point. These car are much more complicated then your average Joe technician can repair. The plan is to the get the car all button up and send it in to the dealership to identify the problem for me. It already been in the MB dealership before for diagnostic. I repaired that part, now there more issues from the scan. As a technician by trade, my job is to narrow down the problem. Time is not permitting.
I been getting information across multiple forums and checking troubleshooting suggestion since this is my first MB. It's not about accepting defeat, it about nearing the problem down as a technician. I have sent in car before to repair shop to help me down narrow the problem and then in turn I fixed it myself.

 

[Craiglxviii]

I think everybody has a valid point. These car are much more complicated then your average Joe technician can repair. The plan is to the get the car all button up and send it in to the dealership to identify the problem for me. It already been in the MB dealership before for diagnostic. I repaired that part, now there more issues from the scan. As a technician by trade, my job is to narrow down the problem. Time is not permitting.
I been getting information across multiple forums and checking troubleshooting suggestion since this is my first MB. It's not about accepting defeat, it about nearing the problem down as a technician. I have sent in car before to repair shop to help me down narrow the problem and then in turn I fixed it myself.

I would avoid the dealership route unless you enjoy open wallet surgery

Ask the forum here for recommendations of local independent MB garages in your area. That will halve the labour cost of your repair.