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2002 ML55 AMG
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Discussion Starter · #1 ·
Hi all, after nearly 3 years of completely trouble free motoring, 2 problems have popped up. The first was the airbag light came on straight after I had to move the passenger seat all the way forward and fold down rear seats in order to move furniture for my daughter. I took it to the local garage thinking it would be an easy fix but they were unable to clear the light. The mechanic told me it was a passenger seat sensor fault? Does this sound likely? He has ordered parts but they are taking a while to arrive, not sure what the cost is going to be here?

Some weeks after the airbag light, I have also got a strange starting problem. This has only ever occurred when the engine is warm or partly warm. From cold it never happens. When I turn the key and release, the starter continues to try to start the car. The car never starts and I have to turn back the key manually to make it stop. It will stop on its own eventually.
Some research pointed to either ignition switch or starter motor solenoid? I mentioned both to the mechanic and he said he checked them both and they were fine. The car just refuses to start when like this despite multiple attempts. This has stranded me 3 times now. There can be days in between when warm starting goes as normal and starter motor disengages as it should and the engine fires up. Then the problems can occur again.
On the 3 times it has failed to start, if I left the car standing for an hour or 2, then it started perfectly. Almost like there is a timed period required, or just for things to cool down? The engine has failed to start when only partly warmed up and not always at full operating temperature.
Could this start problem be key related? I use the standard key which came with the car and is the only one I have.
Thanks in advance for any suggestions:).
 

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Dallas, Texas
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SRS light. Did shop scan for codes?

No start when hot is most likely crankshaft position sensor. It will set code P0335. Again quick scan with simple OBDII scanner would confirm that.
 

· Registered
2002 ML55 AMG
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43 Posts
Discussion Starter · #3 ·
SRS light. Did shop scan for codes?

No start when hot is most likely crankshaft position sensor. It will set code P0335. Again quick scan with simple OBDII scanner would confirm that.
Yes they did scan for codes. My Spanish is not great so did not follow all he said but codes indicated a passenger seat sensor fault?

Would a faulty crank position sensor cause the starter motor to not disengage and just keep trying to start the engine?
 

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. When I turn the key and release, the starter continues to try to start the car. The car never starts and I have to turn back the key manually to make it stop.
From your original post. And yes starter will continue to crank engine in attempt to start. It times out after ~10 seconds, temperature dependent.
 

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2002 ML55 AMG
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43 Posts
Discussion Starter · #5 ·
That is very interesting thanks. If I just leave the key and let it try to start the engine, then it does stop trying after about 10 seconds. I think a new crankshaft position sensor Is in order here.
 
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