2007 e280cdi no crank no start

[Iptvste]

Hi all, im new to mercedes and the forum, i have a 07 e280cdi, for a few weeks its had intermittent lazy starting (slow starter motor) the past few days the srs abs warning as been on the dash but has been driving fine, today it started normal, i went to the shop, done my shopping, got back to the car and it wouldnt crank, the key turns, i can move the gear selector back and forth, all the dash lights up as normal, all lights work, horn works, radio works, everything is fine but it just wont crank, we changed the starter and still nothing, the fuses have been checked and codes have been read but he said there was nothing significant? Any ideas, advice or information would be gratefully received.
Thanks in advance
Steve

 

[W1ghty]

Could it have been the glow plug relay module causing the slow starting ? Maybe the relay has totally failed now ?
What state of charge is the battery now ?

 

[Iptvste]

Hi thanks for your reply, the lazy starter is the starter motor tuning slowly at first and increasing in speed until the engine starts if that makes sense? The battery, heater plugs and module was recently replaced, the battery is currently at 12.4v

 

[W1ghty]

Hi thanks for your reply, the lazy starter is the starter motor tuning slowly at first and increasing in speed until the engine starts if that makes sense? The battery, heater plugs and module was recently replaced, the battery is currently at 12.4v

Hopefully someone who knows what they are talking about will be alone soon ...good luck buddy

 

[Iptvste]

Hopefully someone who knows what they are talking about will be alone soon ...good luck buddy

Thankyou, i really appreciate your time and your replies

 

[MJJ]

How confident are you in the new battery? On the facelift W211s (maybe pre FL too, not sure) If the battery cannot produce 11.5v or more at the point of turning the key to crank, the car will not crank at all - the starter is disabled by the car. With a weak battery, simply firing the glowplugs can often be enough to get the voltage that low.

To help you diagnose this:
- Turn the ignition to the first position, and then press the trip reset stalk 3 times in quick succession. This will bring up the battery voltage on the dashboard.
- Now turn key to position 2, to trigger the glowplugs, and see how low the voltage drops to.
- Does the voltage drop hugely when you turn the key to the crank position, indicating the car is at least trying to turn the starter?

If the battery is good, I would suggest looking at the gear selector position switch. On most cars, if the gearbox is not in Park/Neutral, the starter will not be allowed to turn - I don't know for sure how Mercedes handles this. Is the gear position display next to the odometer correctly showing the car in P/N when it won't crank? Does moving the gear selector a few mm back and forth from the Park position kick the starter into action, suggesting a failing position switch?

Martin.

 

[BlackC55]

It sounds like a low battery or faulty/lazy starter motor. Get it plugged into a Star to see what codes come up.

 

[Iptvste]

Hi, thankyou for your advice, the battery reads 12.6v then activating the plugs it drops down to 11.9v so i think the battery is ok? Iv got another starter so il fit that tomorrow and hope for the best? I cant find anyone mobile close to St Helens with a star thats mobile?
Is star the only way to go??

Thankyou
Steve.

 

[MJJ]

I would say 11.9v after the plugs is borderline low, and would still suspect the battery rather than go to all of the trouble replacing the starter.

Two things to help diagnose:
1) When you turn the key to crank, does the voltage plummet to 10.x V indicating the starter is consuming power, but not turning? (i.e. siezed starter)
2) When you supplement the car's battery with another car via jump leads, boosting the existing battery, does it start fine? (i.e. failed existing battery)

Still suspecting the battery myself.

Martin.

 

[E55BOF]

As MJJ says, try jump starting it.

 

[Iptvste]

Hi, no the voltage just stays at 11.9 when i turn the key to start, i tried a hefty booster pack on it aswell but still nothing.
iv got my dad coming to give me a hand today, hes going to turn the key why i check the voltage on the trigger wire on the solenoid just to make sure thats getting power before we change the starter? Iv already checked the main power cable to the starter solenoid and that is getting battery voltage.
Thankyou
Steve.

 

[Iptvste]

Hi, today i tried turning the key to the start position and putting battery voltage directly to the trigger wire on the starter solenoid the car then started straight away and run perfectly.

Their is faults showing on the dash for abs.

I was told to check the voltage on the purple wire in the front sam when turning the key to start position, there was no voltage at all, i also checked the voltage on the trigger wire on the starter solenoid with the key in start position, again no voltage.

I was told by the same guy that with there being no power to the starter that its the front sam at fault and to replace it with one of the same part number and it will be fine?

I thought it would need coding to the car, if anyone could give me any advice i would really appreciate it, thanks again to you all for your help and advice
Steve.

 

[E55BOF]

Glad you found the fault. It sounds as though you have a knowledgeable advisor heping you; does he say a new SAM needs coding to the car?

 

[BlackC55]

The coding should be checked.