Fitted a new Crankshaft Position Sensor 2 weeks ago and yesterday after driving for an hour the engine light is on.

[John77]

Hi I fitted a new Crankshaft Position Sensor 2 weeks ago and yesterday after driving for an hour the engine light is on. Today the engine light has gone off on it's own.
On plugging into my ICarsoft it says that position sensor 1 for crankshaft has a malfunction. Signal not present. Use a MB Sensor from MB Aylesbury. Any ideas, as it was fine for the last 2 weeks.

 

[brandwooddixon]

Are you sure that its the crankshaft position sensor? I've not known one of these to raise an EML or necessarily store a fault code, instead the engine stops dead.

 

[John77]

Are you sure that its the crankshaft position sensor? I've not known one of these to raise an EML or necessarily store a fault code, instead the engine stops dead.

That's what it says on the fault reader.

 

[AlanGunn]

Has the old sensor still got the "0"ring on it.
Seen them being changed and the ring has stayed in the hole so the new sensor is not as close as it should be.
Was just a thought.

 

[John77]

Has the old sensor still got the "0"ring on it.
Seen them being changed and the ring has stayed in the hole so the new sensor is not as close as it should be.
Was just a thought.

Thank you. I will take a look

 

[Wearsafoxhat]

Are you sure that its the crankshaft position sensor? I've not known one of these to raise an EML or necessarily store a fault code, instead the engine stops dead.

Our Clk (W208, my 01, 320, M112) just cut out without a EML, but my E55 (my 05) brought on the EML and showed on my iCarsft..

 

[John77]

Has the old sensor still got the "0"ring on it.
Seen them being changed and the ring has stayed in the hole so the new sensor is not as close as it should be.
Was just a thought.

Just been to Mercedes and that sensor does not have an O Ring on it or is sold separately as it does not need one.

 

[AlanGunn]

It was just a thought.

 

[supernoodle]

So you changed the sensor because you had a fault before I understand. Is the fault now the same as before? Did you check the wiring first? Changing the part shouldn't be the first step.
It sounds an intermittent fault, so carefully check for wiring damage, lose connectors/pins.
If wiring looks ok, is supply is ok(if the three pin hall effect sensor). Check continuity/resistance is ok, even better check the signal on a scope.

If there was a fault there will be freeze frame logged, which captures key parameters at the time fault set. You can't see it in iCarsoft when using MB mode, but in OBD/EOBD mode a limited one should be visible. Xentry is if course best as the full freeze frames are available. You could at least ascertain if it happens at the same speed each time or is random.

 

[John77]

It was just a thought.

No thank you for taking the time to give advise