Hi folks, I have a problem with my Croma 1.9 16v diesel engine. It will run perfectly well, starting first time every time and then very recently just fail to start at all. This situation can go on for days and then it will just fire up first time.
The car has always started first time since the day I bought it over 3 years ago and I am at a loss as to the reason for this turn around in behaviour.
Any and all suggestions will be gratefully received.
Mike

If the key/immobiliser light is going out then a possibility is the glow plugs.

Even in warming weather diesel engines really need the assistance of glow plug heating.

If one glow plug goes down then this normally results in a slower less energetic start. More than one then life becomes difficult.

If all glow plugs are not working then all engine starts just result in cylinders flooding with diesel and will probably never fire until the fuel has drained into to sump past the piston rings and the air/engine temperature is much more favourable.

So I would be looking at power to the glow plugs and correct operation of the glow plug power relay as an initial starting point.

Carefully..

Gauge what happens as the dash bosrd self.tests.

Immob light ( key..or lock symbol)

Glow plugs.. on for a few deconds .. then off ( no flashing)

While this takes place.. listen to the fuel pump running.. again around 10 seconds

Thanks to both you guys for responding to my request for ideas. Sorry for being slow to answer but I was away from my computer for a week and had no internet connection in any case.
The Croma is with a good friend for fixing and he has informed me that the glow plugs have been tested and the relay changed out as a precaution. I believe that he has already checked out the fuel pump so it is back to the drawing board.
Thanks again
Mike

Re: Engine won't start / Body Control Module (BCM)??

Hi everyone, further to my earlier post I can now tell you that the Croma now runs in a fashion. We eventually sent for a specialist motor electronics expert who got the car running in 20 minutes or so by touching across the contact points of the appropriate relay with a screwdriver.
The relay was tested and found to be functioning properly so no problem there. Using a screwdriver every time you want to start is obviously not an ideal solution and he believes that the culprit could be the body control module which lurks under the dashboard. He has suggested removal and then testing of the offending item by a specialist.
I am going to do this in the near future but in the meantime has anyone had experience of working with and /or replacing/repairing this particular module and knows its full function?
Would welcome any feedback as we are in uncharted territory with this one.
Many Thanks,
Mike

cromaamore65 said:

Hi everyone, further to my earlier post I can now tell you that the Croma now runs in a fashion. We eventually sent for a specialist motor electronics expert who got the car running in 20 minutes or so by touching across the contact points of the appropriate relay with a screwdriver.
The relay was tested and found to be functioning properly so no problem there. Using a screwdriver every time you want to start is obviously not an ideal solution

Would welcome any feedback as we are in uncharted territory with this one.
Many Thanks,
Mike

Click to expand...

What is this relay enabling?

You talk of a module too??


To me its either.. power to glow plug circuit..?

Or power to fuelling circuit..?


Ive had similar.. tell me more
Charlie

Re: Engine won't start / Body Control Module (BCM)??

cromaamore65 said:

Hi everyone, further to my earlier post I can now tell you that the Croma now runs in a fashion. We eventually sent for a specialist motor electronics expert who got the car running in 20 minutes or so by touching across the contact points of the appropriate relay with a screwdriver.
The relay was tested and found to be functioning properly so no problem there. Using a screwdriver every time you want to start is obviously not an ideal solution and he believes that the culprit could be the body control module which lurks under the dashboard. He has suggested removal and then testing of the offending item by a specialist.
I am going to do this in the near future but in the meantime has anyone had experience of working with and /or replacing/repairing this particular module and knows its full function?
Would welcome any feedback as we are in uncharted territory with this one.
Many Thanks,
Mike

Click to expand...

Hi
The BCM is clipped to the bck of the fuse / relay "box" in thr cabin and has the OBDII port built into it (behind panel with small storage pocket) near drivers right knee for RHD car) It provides a network gateway, electronic switching of low power loads like lights, drives the relays for higher power loads and interfaces sensors like the fuel gauge onto the CAN network. It is also part of the security system and is coded to the car. You cannot just swap it out with a used one. You can get a new one from Fiat pre-programmed for you car. When my fuel gauge failed due to a faulty BCM I could not find anyone who could repair it or re-programme a used one.
These people say they can do the nearly identical Punto Mk2 BCM but could no be sure about the Cromahttps://www.jccars.co.uk/Fiat/Fiat%20Diagnostcs.htm
BBA Reman might be worth a call ww.bba-reman.com/gb/catalogue/detailedproduct.aspx?detailedproduct=2177
I managed to fix my BCM using parts form another used one, but I've been repairing electronics as a hobby or job for 40 years.
An intermttent problem is not likely to be a component failure. It is more likely to be a bad connection either soldered joint, connector or relay socket.
If you can provide details of the relay involved and exactly what the electrician did I may be able to help more. For instance if you can short something with a screwdriver to start the car, a hiddent push buttion switch could do the same thing as a last resort or cheap fix.

Robert G8RPI.

My 'bad' relay just got swapped with an identical one elsewhere on the car..

Normal service resumed..

Very strange.. car was a non.runner for months until we traced it ::

Thanks for the quick responses, I will pass on the info to the mechanic this morning.
As to the relay function we understand that it controls the glow plugs and the primary fuel pump and is located in the fuse box under the bonnet. As to exactly how the car started when the relay was shorted I don't know but will ask and revert.
Many thanks
Mike

Personally.. if you know the location of this relay

I would swap it with another on the car

Thats all we did.. it was obviously still functioning.. to a degree

As it behaved in its new position.

Hi again,
The relay has been changed out with others with no obvious benefit unfortunately.
I spoke with the mechanic who demonstrated the screwdriver method and as long as the screwdriver remains in place the car runs ok. Once removed the car stops. The relay is identified by an engine graphic on the underside of the module box.
The next job is to remove the BCM and look for obvious signs of corrosion, non functioning parts etc before investigating if the module can be tested/repaired.
Any new ideas or thoughts will be most welcome.
Any idea of the cost of a new Fiat supplied module?
Cheers
Mike

cromaamore65 said:

Hi again,
The relay has been changed out with others with no obvious benefit unfortunately.
I spoke with the mechanic who demonstrated the screwdriver method and as long as the screwdriver remains in place the car runs ok. Once removed the car stops. The relay is identified by an engine graphic on the underside of the module box.
The next job is to remove the BCM and look for obvious signs of corrosion, non functioning parts etc before investigating if the module can be tested/repaired.
Any new ideas or thoughts will be most welcome.
Any idea of the cost of a new Fiat supplied module?
Cheers
Mike

Click to expand...

Hi Mike,
Was the screwdriver levering the relay body "shorting" connnections together?
The "body computer" is actually two parts, the electronics unit (BCM) and the fuse / relay panel. The unclip from each other. Only the BCM is coded to the car. The fuse panel has pressed metal strip connections and these may be the issue This ebay item

https://www.ebay.co.uk/itm/FIAT-CRO...-CONTROLLER-BSI-BSM-BCM-51786924/324021390051
Has both parts. It might be worth swaping out the fuse / relay panel with yours.

Robert G8RPI