E320CDi no crank, no glow plugs

[Phil Thomas]

Hello and thanks for accepting me to the forum. The vehicle in question is a 2003 E320CDi estate. It was purchased by it's previous owner as a parts car, it drove without issue to it's current resting place. Fast forward 12 months and car now refuses to start - battery is totally flat and it has been parked under some trees so whole car is quite damp.
So, with jump leads everything lights up, central locking good, key inserted and moves through all positions but does not crank. Also, the glow plug indicator on the clock does not illuminate. Now, a chap in the US had exactly the same fault (Youtube) which he overcame by linking out one of the relays in the under bonnet fuse box. I have tried doing the same but no difference.
As the car has stood for so long the rear air suspension has dropped to the floor. Was banking on getting the car running to get it back to normal ride height - recovery will be difficult otherwise. So does anyone know how to get the suspension raised without engine running, or any tips on getting it running?
Many thanks,
Phil.

 

[onefortheroad]

Charge the battery might be a good idea.

 

[Flyinspanner]

Check he hasn’t removed some important bit for parts - then forgotten, like a starter motor

Check mice/rodents haven’t been chewing.

charge the battery, see if you can turn engine with a socket & bar in case it’s siezed

 

[ajlsl600]

As above. Reseat main fuse.get a running car alongside try that

 

[mioba]

You need to jump it from a battery of equivalent AMPS which is attached to a running engine and leave it running for a good 10 mins while attached. once yours is running (and it will from what you say) leave it running for a good 20 mins.

make sure you connect the cables in the correct order. its very easy to fry something and you will be kicking yourself forever.

The electonics will normalise.
Get a gallon of fresh fuel in there.
Suspension is all electronic controlled - no juice no suspension.

mercs hate under voltage batteries. The car will just seem dead until a v threshold is reached.

May be better to get the old battery off the car and at home on a charger overnight to fully charge and desulphur. then test if its holding. without going for a good drive it might well be dead the next day which may mean a new battery (if you intend in getting the old girl back on the road).

keep us posted

 

[Phil Thomas]

Thanks for your replies - the car is quite presentable so if I can get it running will be looking at getting it tested and back on the road. I was using a fully charged heavy duty truck battery to jump off with good quality leads. Initially using the +ve & -ve lugs under the bonnet, which allowed me to open the electric tailgate. Then went straight to the battery with leads - also noticed that an electronic battery cutout switch has been fitted next to the battery. This seemed to be working as all other electrical systems are working. Fault was still the same as previous. All I have at the moment is a Haynes manual which is pretty useless when it comes to wiring diags. I have ordered a copy of the factory manual but that won't arrive until early next week, and I really need to move the car this weekend.
From the Haynes manual it looks like the CDi controller (engine management ecu) also controls the glow plugs and can inhibit the starter motor so looks like something wrong in this area? Imobiliser problem - I think the ignition key has an infra red receiver/transmitter which would prevent the key turning if there was an issue? The key rotates through all positions ok and remote central locking works ok. Should mention previous owner had a sparky look at the car - he got the engine turning over by frigging a relay under bonnet which proves the power side of the starter cct.
So, the plan is to fit a fully charged heavy duty battery to the car, by-pass the electronic cutout switch and connect jump leads to a running vehicle - this should ensure correct volts at the CDi. I will also read the OBD codes which may give some clues. This is the first Merc I have owned or worked on so any assistance much appreciated.

 

[mattkh]

Is it an Automatic?
Does the alarm/immobiliser need waking up?

 

[ajlsl600]

Some benz starters are a little more complex than one might think my aclass starter is chipped to that car.its to do with anti theft.

 

[ajlsl600]

Check this?

 

[Phil Thomas]

Check this?

Hi, thanks for the video. I think failure of this link kills the whole electrical system??
On my car everything electrical seems to be working except engine start.
This video shows the exact same fault as I have.

 

[ajlsl600]

Sorry.start relay ?

 

[mattkh]

.......This video shows the exact same fault as I have.

How dry is that area of the car now? Is there any condensation inside the cover of the relay box?
Might be an idea to get a low heat hair dryer onto that area. The relay pins can also be wiped.

 

[Phil Thomas]

Sorry.start relay ?

I think the sparky that checked it out pulled the start relay and shorted it out to get the engine to turn over - could be faulty but I think the fault is further back. The clue is the glow plug light fails to illuminate. The CDi module controls the glow plugs and I think can inhibit the starter, so it seems the CDi module is not happy, hence not allowing a normal start. Don't think it's immobiliser issue as key turns in barrel and all central locking works ok. I found a very good video on Youtube last night on an E500 with similar no start fault. Turned out to be corrosion on fuse for permanent supply to ecu (the board at end of dash in car). I suspect I have a similar problem - there was lots of condensation inside the car. Will be going back for another go tomorrow weather permitting (car is about 6m from home) see how I get on.

 

[alexanderfoti]

If he turned it over successfully by jumping the relay, but it didn't start, then its missing start authorisation. This is part of the immobiliser system.

I think your route to the engine control module is a good one, it potentially has no power.

Try using a code reader to reade the engine ecu codes. If you cannot get any communication then check the power to it etc. If you can, read the codes and see if it says anything.

 

[Phil Thomas]

A quick update - fitted a good heavy duty battery, and bypassed the electronic cut-out box. Have now got 12.6v on system busbar. Removed checked and re-seated all fuses under bonnet and in fuse box at end of dash. Fault still the same. Fitted dongle to try to get codes - unable to communicate with ecu. Checked at MAF - no 5v ref present. Disconnected connectors at CDi - connector 1 has 96 pins all same size, connector 2 has 58 pins with 1 - 6 larger than the rest. Would assume the larger pins are supplies/grounds. Tested all pins with ignition ON, 2,4 & 6 all ground, 1,3 & 5 should be 12v but only seeing 6 - 7v on all pins. So that is where I am up to - now trying to navigate through the wiring diagrams. Will have another go tomorrow.

 

[ajlsl600]

Is it not job of crank sensor to see,count rpm when engaging starter recognise start attempt by rpm signal which if within parameters instructs ecm to authorise fuel.? I have had low batts fail to give enough crankin speed to do this a number of times. When stuck in de bush a drop of petrol or penitratin oil in ilet has raised crank speed enough for it
Either way a merc capable reader best way to get to bottom of it.,no ?

 

[Phil Thomas]

Is it not job of crank sensor to see,count rpm when engaging starter recognise start attempt by rpm signal which if within parameters instructs ecm to authorise fuel.? I have had low batts fail to give enough crankin speed to do this a number of times. When stuck in de bush a drop of petrol or penitratin oil in ilet has raised crank speed enough for it
Either way a merc capable reader best way to get to bottom of it.,no ?

Yes CDi module must sync with crank/cam sensors before allowing fuel but my car is not turning over (off the key). So think the problem is supply to the CDi module. If it was immobiliser issue would expect no voltage at pins 1,3 & 5 so will chase this. Also no comms with OBD2, so suspect CDi not actually running??

 

[ajlsl600]

Does sound like u will get there In the end. They are now made to defeat the diy. If you can bypass relay and get it to crank maybe yr ecm fried or?? Rodents campin in yr wiring???

 

[mattkh]

Thanks for the update. Two ideas:
1. Clean the main earth connections on the chassis.
2. If access to the starter solenoid is good, connect a lead from the battery positive to the solenoid. If engine turns over, then it rules out a lazy starter.

 

[hmang]

Hello and thanks for accepting me to the forum. The vehicle in question is a 2003 E320CDi estate. It was purchased by it's previous owner as a parts car, it drove without issue to it's current resting place. Fast forward 12 months and car now refuses to start - battery is totally flat and it has been parked under some trees so whole car is quite damp.
So, with jump leads everything lights up, central locking good, key inserted and moves through all positions but does not crank. Also, the glow plug indicator on the clock does not illuminate. Now, a chap in the US had exactly the same fault (Youtube) which he overcame by linking out one of the relays in the under bonnet fuse box. I have tried doing the same but no difference.
As the car has stood for so long the rear air suspension has dropped to the floor. Was banking on getting the car running to get it back to normal ride height - recovery will be difficult otherwise. So does anyone know how to get the suspension raised without engine running, or any tips on getting it running?
Many thanks,
Phil.

phil is this a 210 or 211 ?