W220 S320 CDI 2000 - Weird start behaviour, TipStart not working?

[MarcBG]

Hi all, hope this post finds you well,

Since I've had this car there's been a strange problem with the start process that's been impossible to diagnose - MY 2000 S320 CDI

When I go to start the car, I have to hold the key in position 3 in the EZS until the engine has started. If I let go of the key to position 2 before the engine has started, it stops cranking immediately, and I have to take the key out and put it back in and start all over again.

Same thing happens when starting the car via the keyless go button on the shifter knob. If I let go off the button too early, the cranking stops before the engine has started.

Normally in any other Mercedes you just flick the key briefly to position 3 and it will start cranking automatically until it detects the engine has started. This is what is not working on my car.

The car shows no fault codes on Star Diagnosis. The EZS was replaced a few months ago because the original one had failed, but that did not fix this problem either.

What could be the problem? I'm out of ideas and would like to get this 'Tip Start' function working again, some day

 

[LostKiwi]

I wonder if there's a coding option not set in the new EZS?

 

[MarcBG]

I wonder if there's a coding option not set in the new EZS?

This is what I thought too - but I wasn't able to find any setting for it in Star. Will double & triple check again tomorrow

This start problem also happened with the old EZS too, it's been there ever since I purchased the car

 

[mersum1es]

This is weird... I remember reading one case (I think it was W210) where tip start didn't work, but that car had bad water ingress in ecu boxes and several other elctrical malfunctions too...

Tip start is automatic transmission feature only, so those cars with manual transmission option availabe culprit could be coding to 'manual' but since all W220 are automatic and fact tthat wrong coding should give several other faults, I can't see how that could be possible.

 

[MarcBG]

Hi, far as I know this car has had no water ingress and everything else is fine on it, just this damn tip start feature. The AT/Manual coding is a good point but as you say that would have triggered a lot further issues..

How ever

Just found this - maybe it could be on to something?

If you receive customer reports in the above model vehicles of the tip start cycle ending prior to the engine starting, this may be due to the tachometer
momentarily jumping above 2000 rpm causing the starting procedure to be aborted before the engine starts.

To resolve, perform the below steps.

1.Remove starter per WIS instructions below.
2.Lightly coat teeth of starter ring gear with paste, A000 989 76 51

Attached the document below

 

[mersum1es]

Never heard that, good found and worth to check. Capture live data of tacho...

 

[MarcBG]

Will check the tacho next mersum1es and post back, it's the last shot because I just tried removing the crankshaft position sensor and lubed the flywheel in hope that would reduce friction with the starter but no luck.

Also tried starting the engine without the crankshaft positition sensor hooked up but still stops cranking when I let go off the key. Damn it