W203AL

Well, i fixed the ECU and so far no problems... i was told the ECU had physical problems and software problems.

I will update the thread in 1 month and report if there are any errors... otherwise i really hope i have solved the problem

Hope this thread will help others...

cheers.

jkowtko

It's been a little over a year now ... is your problem solved? I just had a non-start episode this morning so I may be in for the same troubleshooting experience ...

Thanks. John

adam.itech

Hello everyone,

I have exactly the same problem as you describe happening more and more frequently on the mornings only.
I can insert they key, I can hear bzzzz, Key is accepted by immobiliser and locked in position, position2: ignition lights come on as normal, glow plugs and air-bag lights disappear after while, so all OK, no errors. Relays are clicking as normal.
Turning the key into position3: nothing, starter motor is not giving a sound.
After 30min trying, locking-unlocking finally I can start the car.

The problem is not happening during the day, only on the mornings.

I did check described by you relays, fuses and obviously looking poor connectors but I cannot find anything obvious. I swapped relays and fuzes, cleaned connectors with electric liquids. I disconnected the negative battery plug for 30min. Car cracks normally in the evening, but when I tried in the morning the issue still was the same 30min trying and finally it started.

Fuse 52,57,31 checked, removed & tested,
Starter motor relay "R" removed & tested with meter under load, also swapped with another one with the same parameters. M, P, B, F relays also are also looking to be working OK.
I have 2 keys, problem happens with either of them in the same way.

I'm going to replace Fuse 52 (15A with 20A) today. Then I'm running out of options.

Car: Mercedes C220 CDI Coupe (W203), year 2002, 6 Speed Manual.

Please assist. I'm running out of options.


Here I also saw that fuel pressure needs to be above 3.8 bar / 55PSI for cranking to be allowed. Is it easy to test the pressure using home tools or I need specialist hand?
https://mbworld.org/forums/c-class-w...t-process.html

adam.itech

..deleted post

adam.itech

Hey Everyone! I think I managed to resolve my problem with "Early Morning no Cranking"! and would like to share it with you.

I pulled and cleaned again all connectors I could see in the engine bay. On the NSF near break pump, close to wheel arch, there is some sort of regulator, with 2 connectors and bigger ground cable, which was a bit corroded. I properly cleaned that one. I think this fixed “no cranking problem”.
The only meaningful error I saw on the BOSH ODB scanner was: "P0100 Mass or volume air flow circuit too high" and no other related messages which people say usually should come up. I cleared all errors afterwards.

The local Mercedes specialist told me that there were problematic ESP modules fitted in 2002-2006, after that they used working correctly modules. This most likely caused an issue in my case and somehow after a few shakes that started working again (for who knows how long).

Now, I have left with another issue which happened in the middle of the cold start problem: When the engine is cold, everything works fine. When the engine gets warm, something in electronics triggers and is not allowing me to go above 3K RPM. P0100 code is the only one I get.I put the post here https://mbworld.org/forums/c-class-w...100-error.html

Please help out if you can

adam.itech

Now my car is not wanting to start again after happily turning the starter motor for almost a year with no problems. In the meantime, I put a new 100AH battery, 5 months ago. I also replace faulty MAF. Now I don't have any error codes popping up on the dashboard or ELM OBD2.

I was able to start the car earlier with this weird behaviour of opening and closing passenger doors with a bit of a force. It used to shake something and the car was starting. Now, this trick does not work any more.

I'll try the earlier mentioned trick with using another running car to start Merc with jump leads. Extra power might let me start it to get into the workshop at least. And I'll look for this clutch switch (could you let me know, where is it located - I'm still a newbie in this area).

Once I get access to STAR, maybe I will know why it seems like the power is not getting into the starter motor at all and what is causing it.
When I put the key in position 3 (ignition), OBD2 signalised a tiny drop in voltage, so looks like things are OK here but where they are not?

adam.itech

Front SAM C220 CDI

Merc garage replaced a few relays, as they come up as not working well in STAR, yet I started to have the intermittent problem with starting a car again. Taking Relay S out and putting is back worked a few times. Then I started to have a new series of car not starting for 30min of trying. I can feel and hear Relay S and others clicking, but it looks like power is not going to starter motor still. I can’t see any corroded area or any obvious problem. This pict can help for starters - focus on Relay S + Fuse 52

adam.itech

After having the wiring with a control bulb done to the starter motor, I observed that power is going to it (so the signal is going too!!!), but there were these annoying occasions, where the starter motor didn't want to start cranking. I had enough of not knowing when the car would not want to start. I have replaced the whole starter motor. I think the new starter motor is cranking a bit faster. You can play with replacing starter motor brushes, solenoids, checking connectors for rust deposits. I simply had enough on this occasion.