96 E300D Problems
 

ive had this car since brand new in 96. it has a little over 93k miles. Driving one day the car just shuts off. And it wont restart. The gauge cluster doesnt work and it seems that its not reading the key as it just says to Take Key as it is not reading it. And the car is not starting. its cranking but the car doesnt fire up. lights in the cluster dont work except the SRS warning light. Fuses are all good and i cannot get a scan tool to read as the car doesnt turn on to the ON position. Any help is appreciated.... thanks in advance

I'm assuming it restarts after sitting minutes or hours and runs normally afterwards?

That being the case you probably have an intermittent K40 relay that causes the shutoff valve to close while driving "as if key were turned off". No warning. It is the front most realy in the computer box on the right (pass) side of the engine compartment. Costs ~$80 and takes 10 minutes to pop in and out.

K40 is a common failure, if yours is original you are WAY overdue.

Thought about this one some more when I turned mine off tonight and the display said "take key". I dont remember mine doing that when it had the classic K40 fault and died w/o warning while the ign was turned ON, although it may have. As I'm sure you can appreciate, when that fault occurs you are pretty darn busy looking for some place to pull over to.

I suppose its possible you've got an Ign/EIS fault. A fault in that system could not be read with a typical OBDII scanner and would be a very uncommon problem......I think I would still replace the K40 unless it was known to have been replaced quite recently, in which event it would be appropriate to have it scanned by a qualified tech using SDS.

This is basically the problem that my wife's '96 E300D has. Sometimes the dash lights won't come on and then the engine will crank but not fire. If the lights do come on, the engine starts fine. If the K40 relay is disconnected (all four connectors), the dash lights still work except for the check engine light. As I recall, we also got the "Take key" warning and sometimes the alarm goes off and has to be silenced with the infrared key fob. The main difference between this car's problem and that of Phaze2bb's is that ours doesn't stall while running...yet. :D

My scanner shows no codes, by the way.

It still might be worth replacing K40; I just hate throwing money at a problem rather than understanding the failure. But sometimes you just have to bite the bullet and move on.

Jeremy

thanks for the help guys. But even until now the car still does not start up. its bbeen a little over 3 weeks since it stalled. And i had a guy that worked at a local dealership out here take a look at it and he didnt even know whats going on. So could this be still the relay problem? because my car still hasnt fired up? Thanks alot everybody

If you crank it for 30 secs by manually holding key at the start position does it sound like it WANTS to start? Or does the engine just spin, and spin.

Is the CEL lit up?

Electronic key or traditional key?

Could be the EIS system is faulty.

also, once again, I will mention the battery and low voltage which can wreak havoc on these systems. First check all connections at the battery and grounds from it and measure voltage. You may have a bad cell, how old is the battery? It can deliver enough juice to crank but still be below the voltage threshold for the electronic systems to operate correctly.

I'd also replace the K40 just for the heck of it...it is a cheap part and so prone to this type of failure that it might just be the cause of this problem. If the K40 and battery turn out to be dead-ends you probably need to get it to a M-B dealer and have them scan it with the proprietary scan tool.

Ok I replaced the K40 relay and also the battery. And the problem still exists. I dont know what is going on still. I tore the car apart and cant see anything that could be faulty. Anymore help is appreciated....

thanks again

Did you try this?

What kind of key do you have - normal, or infrared?

try a different key.....also move gearshift lever to neutral.

yup tried all these above. The car doesnt want to start it just sins and spins. I also have the infared key with the flip out key for ignition. Also tried a different key and played with the gearshift. There is no CEL as the lights in the cluster doesnt come on. Any other ideas? Thanks in advance

With the hood up, turn the key to position #2 while listening for the click of the shutoff valve openning. It the balck palstic valve on the side of the IP. Let us know if you hear it.

My guess would have been the EIS had failed (electronic ignition system) but if the starter is spinning then it's something else.

As Terry has said, look at the shutoff valve.