Technical Crankshaft sensor woes!

[LEXCERM]

Hi there,

Over the past couple of months I've had the crankshaft sensor replaced on no fewer than 3 ocassions! I've been told that the crank shaft teeth are all fine and that the sensor is clean and not loose. The sensor is an original Fiat one.

The code read keeps showing "crankshaft sensor fault."

Recovery truck takes car from home to garage, then car starts up again. Code reader then elimintaes the fault.

What can be causing this constant sensor fault?

Thanks in advance,
Paul.

 

[daza001]

What car is it

 

[LEXCERM]

Er, sorry - thought I forgot something!

It's a 53 plate Fiat Multipla 1.6.

Rgds,
Paul.

 

[fingers99]

Odd. I'd suspect -- as it's an intermittent fault -- that it may not be the sensor at all, but the wiring upstream of it. Search that cable out (generally 3 wires) and look for any evidence at all of fraying, chaffing, etc. It'd also be worthwhile pulling the relevant connectors apart and putting a little silicon grease (many factors now stock it or try an electronics shop) or (inferior, but still useful) vaseline in it.

 

[Mad Hatter]

I had exactly this problem, gradually getting worse/more frequent over a couple of months; it was the TDC sensor. I believe that the reason that it is intermittent is due to the sensor breaking down once it gets hot, and once left to cool down a bit the engine will then run again for a while.

edit
Oops, should have read the full post. I think that this only applies to the JTD.

 

[LEXCERM]

Thanks fingers99 and Mad Hatter for your advice. I'll check the wiring again. The odd thing about this is that everyone tells me that the sensors can play up if it gets hot, but mine is the opposite. It's from cold!

For example, I got in my car first thing this morning and guess what - the damn thing wouldn't start again!

I suppose it's a FIAT garage for me.

Cheers,
Paul.

 

[LEXCERM]

Update:

So I tried it again this evening, and the engine still turns but doesn't spark at all. Then I had a eureka moment.

I shoved it in reverse, then turned the key and let the clutch out quickly (as if to jump start it) and "hey-presto" the engine started!

Shortly after, though, the "engine faulty - contact garage" warning message appeared.

FIAT - here I still come.

Paul.

 

[LEXCERM]

Update: I took the car to a local garage and told them of the problems. I was told that whenever you change a sensor part, you need to regsiter it with the ECU otherwise you will get problems. They charged me £40.

So I now wait with baited breath to see if this will do the trick.

 

[Mr.Multipla]

Any luck on registering the sensors with the ECU ?
Only asking because i have a 1.6 ELX that had an intermittent Engine Control Fault , that would beep every couple of months, Then it got to not starting & finally beeps constantly every 10 seconds while the engine is running. It's been on several machines & only one found Crank angle sensor & water temp sensor faulty , we have replaced these , but the garage could not reset the faults. I was told to disconnect the battery over the weekend to see if this would clear it, but to no avail.
I'm hoping that this could be the solution .... And maybe I have to do the same thing & register the new sensors with the ECU, If so do i need to go to the fiat garage & get it done on their machine ?
Tx In advance

Chris

 

[T14086]

whenever you change a sensor part, you need to regsiter it with the ECU otherwise you will get problems.

this is correct

 

[Mr.Multipla]

Thanks Ti ,
I have spoken to Fiat & they say it's £80.50 p.h , Any ideas if this is a quick job , I don't want to be stitched up As the person on the phone said it could take longer than an hour. Last time it was on a diagnostics machine it took less than 15 mins.
Thanks in Advance .

Chris

 

[T14086]

£80 including parts is good, cranksensor is at back of engine so you will need ramps/stands etc...personally i'd rather see it on a correct 2 or 4 poster garage ramp but thats just me.

 

[Mr.Multipla]

Hi Ti,
As mentioned in the earlier post I have changed both sensors , i just need the ECU reset to get rid of the annoying beeping which happens non-stop every 10 seconds while the car is running.

Ta
Chris

 

[T14086]

beeping? Do you get the 'engine ctrl faulty' message aswell?

 

[Mr.Multipla]

yup , I turn the ignition on & all is fine , it comes up with "OK", I then start the car & instantly i get "Eng Ctrl Fault" , "Contact Garage" & the thing beeps really loud from the dash twice every 10 seconds , I had to do a 33 mile run in it the other month , Had to put tissue in both ears , open the windows & both sunroofs & play my wifes "Will Young" Cd at level 40 on the cd player to drown out the noise.

Chris

 

[T14086]

fault must still be there then, you changed the cam sensor (the one behind the timing belt) ?

 

[Mr.Multipla]

I'm sure it was the crank angle sensor , don't know about cam sensor
I'll take a photo of the ones We changed & put a vid up of the car dash when running .

(Edit) Uploading vids now to Youtube. The printout i have from the fault code reader was Crankshaft Sensor & P0115 Coolant temperature Sensor Short to B+

CHris

 

[Mr.Multipla]

Ignition on & Engine start showing ENG CTRL FAULT


Sensor location

I couldn't get under the car to show the other one changed without a ramp or jacks.

The Diag machine gave crankshaft sensor & p0115 Coolant temperature sensor short to B+ faults

Chris

 

[T14086]

did you read the errors on a generic code reader or FIat diag equipment....there is a difference. I suspect the error is 'difference between cam & crank sensor', basically the ECU is seeing different positions from the cam & crank sensor. If crank sensor has been changed then this leaves the dreaded cam (phase) sensor behind timing belt.

Obviously check the coolant temp fault first.

 

[Mr.Multipla]

Cheers T1 , It has been on so many diag machines I have forgotten , but one was a main Fiat / Alfa specialist a friend in the trade told me to take it too.
I guess i'm going to have to cross the palm of another Fiat garage next week then .