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Discussion Starter #1
A few days ago my 1.6 cut out, EML came on and as I had my ODB cable in the car, I checked the fault. It was P0335 CPS circuit malfunction.

Car started up again, so I left the fault there and drove home. Checked again and the fault was intermittant (rather than present). I cleared it and it's been fine for the last few days.

Is this a common sign of impending doom, or just the car having an Italian day and throwing it's pasta out of the pram for no reason? I'll buy a new sensor anyway as they're cheap, but as there's a whole pile of other things that could cause a random malfunction, is there anything else to look out for?
 

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When they start to fail they tend to do it when the engine is hot and work again when the engine cools down (thermic fault).
The crank sensor isnt very expensive and easy to replace when you have a TS engine, its placed near the starter motor and don in 15 minutes.


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Discussion Starter #3
The same happened again yesterday, on the same piece of road actually! Today it's been fine but what I noticed yesterday was the speedo was erattic and dropped to zero after a few seconds of coasting. Today I turned the ignition off whilst rolling and turned it back on, engine was off obviously but the speedo kept working just fine.

I've already got a new sensor on the way, but is there a chance this is something else and it's just chance that both times the ECU has determined that the crank sensor is at fault when it's actually an electrical issue elsewhere?
 

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I'm not sure how the speedo might be involved, or could be a symptom of the engine not running ("not sure" = haven't a clue...).

Does the tachometer fail to work? When a CPS fails the tachometer also stops working (because the ECU drives the tachometer). If the CPS isn't working then the ECU 'thinks' the crankshaft isn't rotating because it isn't getting a signal telling it what the crank is doing, so doesn't operate the tacho (even the crank is rotating, i.e. with the engine being 'driven' by the forward momentum of the car, or the starter motor).

Regards,
John.
 

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Discussion Starter #5
I'm not sure how the speedo might be involved, or could be a symptom of the engine not running ("not sure" = haven't a clue...).

Does the tachometer fail to work? When a CPS fails the tachometer also stops working (because the ECU drives the tachometer). If the CPS isn't working then the ECU 'thinks' the crankshaft isn't rotating because it isn't getting a signal telling it what the crank is doing, so doesn't operate the tacho (even the crank is rotating, i.e. with the engine being 'driven' by the forward momentum of the car, or the starter motor).

Regards,
John.
Yeh the tacho doesn't know which way is up for a second then just drops to zero. Seems odd that it would affect the speedo , the 2 are completely unrelated apart from the ECU taking a speed signal.
 

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Park your car up and let it idle until it comes up to normal temperature.... usually 90c.....when my crank sensor was failing the engine used to cut out around this temperature.
 

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Discussion Starter #7
Park your car up and let it idle until it comes up to normal temperature.... usually 90c.....when my crank sensor was failing the engine used to cut out around this temperature.
Same temp and mine start to fail. Got new one on the way so hopefully all shall be well. Went for a genuine one rather than whatever I can get at a motor factors, just under 30 quid so not a huge expense :)
 

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The crank sensor has a rubber O ring that sometimes gets left behind when you remove the old one. If you then put the new one on top, the sensor is to far away and will not work.
 

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Discussion Starter #9
Got new one in today, took longer than it should as I couldn't quite get the car high enough to comfortably get under it but got the job done.
 
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