2005 E320 CDI
No crank, no start on and off for a year now. When glow plug light comes on, then the car will start, when the glow plug light does not come on the car will not start. Recently, it can take as little as one or two key cycles to start, other times, 10-15+ cycles to start.
All fuses and relays have been checked.
Dealer says I need new ECU and updated EGR valve.
Decided to get my ECU repaired. Repair shop checked it out, they can find nothing wrong but they will order 2 or 3 drivers, which they need 7-10 days to order in. Once they receive them, my ECU goes back for the driver update. Hopefully this will finally correct this issue.

My question to all you gurus re the start circuit.
What function does the glow plug controller play in the start circuit. Is this the box under the intake, and does it receive the signal from the ECU and once activated send the signal to the dash light for the glow plug light to come on. Or is it all controlled by the ECU? Just don't know if my issue is ECU related or is it perhaps the glow plug controller or something else.
Thanks in advance.

 

I'd be more interested in checking the worthiness of the ignition switch to start with.
Pulling codes, if any, would be helpful too.
If the ignition switch is on its way out, I wouldn't expect codes.

 

Glow plug is really needed when everything is very cold. Once it is warmed up, no glow plug should be needed.

Do you need to get the light even when the engine is fully warm?

Peter

 

Yes, the glow plug light needs to come on, even with the engine hot. If it doesn't come on then the car will not start.

 

In this case, I don't think correlation is causation. On a hot engine, you can have all 6 glows disconnected and the car will still start. Hell, on a COLD engine these common rail engines will still start just fine down to well below freezing.

 

Agreed, but my starter will not activate unless the glow plug light comes on.
Still don't know if its the ECU that is faulty, or something else that is driving my issue. (apparently there are some drivers that still need to be installed in the ECU, but haven't heard back yet from the rebuilder)

 

When you turn the key to the ON position what does the instrument cluster look like? Is it lit up as normal or does it stay dark?

 

The car started up first try this morning when I went to run some errands, glow plug light came on, I was good to go.
Just back now, turned car off, and tried to start the car again, went through about 10 key cycles, I could not get the glow plug light to come on and could not start the car.
Even turning the key to start position, the starter will not operate (unless the glow plug light comes on).
The cluster lights up completely as normal.
Key In position 1 the SRS light comes on, but goes off within a few seconds, center display comes on.


Key in position 2, center display is on, all three guages light up, notice the glow plug light is not on. Car did not start, fan runs at high until I turn the key off.



Got three messages, one is the SOS, which has been on for maybe 1 year plus, the ABS and the ESP message also came up just now. Sometimes the battery warning comes up as well, but not this time.
The ABS and ESP messages clear on their own once I get the car started, the battery warning sometimes stays on and my convenience features are not available. If I turn the car off and try to start it again, providing it starts, the battery warning goes away. I just installed a brand new battery about a month ago.
I drove around all morning with no messages other than the SOS warning.
Just to add, I took the trunk main fuses apart (in front of the battery), and cleaned the two fuses, the BCM and ground, as well as the rear SAM fuses, and the ground connections.
I inspected the rear SAM circuit boards, and there was some slight water damage, but cleaned with alcohol and reinstalled.
The front SAM fuses and relays were all cleaned as well, there is no water damage to the front SAM or ECU.
The starter relay is brand new when car was at the dealer for troubleshooting back in December.

 

Hi Tbeiler, I have the EXACT problem. Started with having to turn the key two-three times to 20 times or more, and now it can not be turn on. Whenever key in the third position, fun starts to run high speed, and ESP warning sign.
Frustrating thing is that after clone the ECU to an used one I bought from EBAY, it still doesn't work. Now it could be the used ECU ($500) does not work or something else.
In the past, whenever I started the car in the morning, it will be good for the rest of the day (glow plug on, can start the engine), meaning hot engine will keep whatever good. However, the next morning I would face the same on glow plug light, no start issue again.
Anybody with experience fixing this problem?

 

Are there any OBDII codes?

What does the car say the battery voltage is before the engine is running?

I am wondering about that SOS message and trunk corrosion problem mentioned. Have you looked to see if the antenna splitter is corroded? If you follow the rear window antenna wire down out of the rear window and down behind the left trunk carpeted wall, it will connect to a (matchbox sized) splitter glued to the inside of the LR fender. On mine. Rain trickled down this wire and corroded the connectors. I started getting SOS error messages even though I don’t have SOS. The connectors UNC lip in a strange way and with corrosion, were difficult to remove. I don’t recall exactly but maybe the connector stays on the splitter and the three cables come out.

Anyway, on mine, I was able to clean them and filled the connectors with bulb grease to prevent further corrosion. I think I also I hung a tape flag to direct any new water coming down the cable and drip harmlessly off the cable. This stopped the problem for eight years. When the SOS message came back, I then had to repeat the process but it has been good for several more years.

Good luck,
Peter

 

I have sent my ECU out for repair, it has been weeks since I have heard from these guys. Little to no communication,
Last I heard the module is coming from Europe. That was almost 2 months ago. Hope that once the module arrives, my car will be back to normal.

 

Thank you Peter and tbeiler for your time! I will look into the left trunk area. Meanwhile I set up an appointment with local MB dealer to do a diagnosis again next month, and possibly, they will recommend replacing the ECU, and possibly, that may or may not fix the problem, and then they will give me another quote. What can I do?
Since I got this car in 2015, it has been flawless (except for stuff I can fix: MAF sensor, brake, engine mount, and crazy squeeze noise...... ) till now and I hate to let it go...

 

I sent my ECU to this place to fix, they did not get any error code after scanning and did a repair anyway after my permission. That did not fix the problem. I then purchased an used ECU module (identical to mine) from ebay and send both to them to do a cloning. That did not fix the problem. Did any one have experience with them?
XeMODeX Technology
2-6150 Kennedy Road
Mississauga, ON L5T 2J4

 

I also contacted XeModex, and at the time, perhaps 2 years ago, they were not capable to repair the ECU from a 2005 E320CDI.
They told me this up front, before I sent off my ECU to them. So I searched elsewhere.

 

Guys,

So you guys might want to think this through step-wise:

1. The EIS system (Electronic ignition) That goes through 2 checks - Authorization 1 and 2 - both of them should turn to YES from NO to then send ground signal to your starter/ glow plug relay circuit on the ECU.
2. Once that is true - then the ECU starter circuit powers on and turns the starter motor after lighting the glow plug relay module.

NOW these things can be tested for on a STAR system - which I dont think all of us would have.

BUT - I suggest buying the iCarsoft MB 2 or the Autel AP200 - I personally own the Autel AP200 and for 60 bucks off amazon you can read Mercedes-specific codes. Once connected to the cars OBD2 - Go to live data and check for start authorization - That would show you if your EIS needs to be replaced. If thats not the issue then it might be the smd relay chip inside the motherboard of the ECU. If thats faulty then the ground activation by the EIS is not seen at all by the ECU and thus it wouldnt start.

Hope this helps.

-KM

 

Great idea!
My problem is that after the XeModex clone using the used EBAY ECU, i can not communicate with my scanner via OBD2 any more. So the EBAY ECU may have other fetal problems. I agree with you that things get complicated quickly if the steps were not taken wisely.

 

Latest update: after sending the faulty ECU to CarTech Electronics in UK for cloning, all problem fixed. They know what they are doing (probably because there are way more CDIs there?). I almost gave up on this beautiful car...