W210 ignition system troubleshooting
 

My 98 E300D (W210) just stopped a few days ago (battery died), and once the battery issue was fixed, now won't start. Key in ignition lights up some of the dash lights, but starter wont engage. Checked out starter and starter relay - OK. Can manually turn over but won't fire up. Suspect everything from FOB to ignition switch to computer. Can anyone tell me how to proceed? Don't want to tow it to dealer - know:confused: how that'll end.
:confused:

Will it start in neutral?

No, nothing in either Park or Neutral

Before you get too far. Under what exact conditions did the car stop? ( driving , sitting at a light, trying to restart? ) Did all of the electrical items in the car go out? Were they dim or completely blank?

Use these definitions for clarity.

Cranking = the key is turned and an electric motor ( starter ) rotates the engine.

Running = after cranking the engine, it consumes fuel and no longer needs the starter to rotate.

How did you determine that the battery had failed?

Failed = won't accept a charge / can't pull sufficient power out of the battery to crank the engine. ( A gas tank that has a hole in it. )

Discharged = a battery in good condition that has had electricity pulled out of it and is waiting to be recharged. ( A non leaking gas tank that is empty and is waiting to be refilled. )

I'm thinking that your first problem is a symptom to the one you are having now.

Tell us about the battery that is in it now? Is it new? CCA? Are the terminals clean and making good contact? If you charged the battery and it still won't work get a new battery of the largest size/cca that you can fit in the hole.

I can't help much with the car. To new for me but I would ask, does it have a security system, factory or add-on? If so, could that be the problem?

PaulM

Died, due to a dead battery (cable problem - replaced)
After recharging battery engine won't crank.

Opened the compartment (engine compartment) that houses the starter relay (and computers I believe) and tested relay, and was able to get the starter to crank (but didn't start the engine)

There was some moisture in the compartment. (We've had a monsoon season this summer in FL, and vehicle is parked outside) Dried it out but didn't make a difference.

Thinking the FOB might be the issue, I searched for a new fob. Found a replacement MB fob online, (www.keylessentryfobonline.com) but after contacting MB dealer was unable to get a verbal confirmation from the dealership that they are willing to program a remote that was purchased through a 3rd party.
Seems that they are less than willing to help program a remote that you purchased from someone else and I have been told that some dealerships have gone as far as removing the necessary equipment for reprogramming keys from their dealerships.

For an 18 y/o vehicle, I'm pretty sure that towing it to the MB dealership (even for a diagnosis) would end up with a repair much higher than the value of the car itself. Don't know if there are any MB techs that have a mobile diagnistic capability in the Tampa Bay area.

"" Died, due to a dead battery (cable problem - replaced) ""

Did the wire leading from the alternator fail and battery stopped charging?

Even a battery that would barely crank a lawn tractor won't cause the car to stop once running if the alternator is working so the stoppage might be from another source.

Was it a large cable that leads directly to the battery that failed? How did it fail, broken wire , corroded completely through, insulation falling off and touching ground?

If this was the smaller wire on the positive terminal that feeds the body, you may still have a break.

On a 98 and up W210, if the key fob turns, the fob is OK. These use an electronic steering column lock not a mechanical key. When you insert the fob, you will hear a ZIP sound of the column unlocking.

I don't think the dealer can program a FOB for electronic lock even if they wanted to, you need a bootleg China programmer for that. But, if the key turns you problem isn't there.

Do you have access to an OBD2 reader? You need to see if the engine computer is waking up.

Don't have access to an OBD2 scanner (at least one that works with Mercedes). My mechanic has a top of the line scanner, but doesn't work with MBs.
Probably asking a dumb question, but any ideas (other than the dealership), where I could find an OBD2 scanner for Mercedes?

On each of these scanners there should be a generic OBD2 mode that will give you codes and limited data. When a specific car is selected, that opens up manufacturer specific codes / test functions.

There are a few different communication standards but any scanner made in the past 10 years should be able to communicate.


This makes absolutely no sense. .

Any OBDII scanner will work on the connector by the drivers knees (under the dash). I think who ever told you that was talking about the 38 pin connector which is a different matter.

Yea, I was somewhat confused by his statement that it would turn over but not crank until I went back and re-read it. Last 99 E300 I had in the shop that would not crank it was the switch mounted on the side of the gear selector mechanism that needed to be replaced. MB p/n 210-545-13-32. Someone had spilled a coke in it or something. Wonder how many miles are on the car?

Switch on the side of the gear selector mechanism... Hadn't thought of that.
Car has $187k miles on it. About 15k miles ago, I had the trans completely rebuilt, and so that's my next area to check.
Thanks also for the info on the OBD2. So it should tell me (once I pull up the right vehicle) if the ignition switch to computer communication is working OK?

The neutral safety switch is internal to the transmission conductor plate and isn't in the in car gear shift.

Regardless, for an otherwise properly operating car, it the gear shift was in drive or reverse, you had ignition key to the on position then jumpered the starter, the engine would start ( and drive away ) . A neutral safety switch isn't the primary problem on your car.

No it won't. It is just a code scanner. I guess I was confused by your statement about OBDII scanner. That is not what you need for the specific testing you are talking about. You would need the dealer scanner. However I have never heard of a good key not communicating with the engine computer, though I suppose it might be technically possible. I am not sure the more likely causes have been ruled out yet, like fuel pump, fuel pump relay, etc. The suggestion was to use the OBDII scanner to see if the computer is alive I think. I guess it would confirm that.