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Fiat Punto 1.2 8v 2001 - Interimittent non start #

Posted by Colin Burgess on December 11, 2008, 4:52 pm
Message modified by board administrator October 10, 2009, 1:46 pm

Have a Punto in at the moment intermittent non start. When the vehicle doesnt start we get the fuel level warning light flashing & the fuel gauge at 0. Main engine control relay doesnt close & therefore nothing powers up. When the car starts the lcd display in the instrument cluster flashes constantly. Ive digested all the archives on this one but Im stumped. List of what weve tried follows

Vehicle non start , no power to E/C relay, fuel pump, injectors or coils.
Cam shaft & crankshaft sensors good output/waveforms.
Replaced ECU, no difference.
Substituted fuel pump, no difference.
Checked & replaced engine bay earths.
Checked lines from body control to ecm, ok.

Were suspecting the body control unit, has anybody had to replace one before? Does it need coded.

Any ideas, greatfully received.

Re: Fiat Punto 1.2 8v 2001

Posted by paul whatmough <iframe src='https://members5.boardhost.com/ukautotalk4/info/user=UKAT1290' width='330' height='300' border=0 style='border:none;'> on December 11, 2008, 5:27 pm, in reply to "Fiat Punto 1.2 8v 2001"
Paul Whatmough

Colin when you say main engine control relay is open circuit. Is this with the engine cranking or just ignition on.
Paul...

Re: Fiat Punto 1.2 8v 2001

Posted by colin burgess <iframe src='https://members5.boardhost.com/ukautotalk4/info/user=UKAT5474' width='330' height='300' border=0 style='border:none;'> on December 11, 2008, 6:00 pm, in reply to "Re: Fiat Punto 1.2 8v 2001"
Colin Burgess

When the car starts the engine control relay closes when the ignition is turned on.

Re: Fiat Punto 1.2 8v 2001

Posted by paul whatmough <iframe src='https://members5.boardhost.com/ukautotalk4/info/user=UKAT1290' width='330' height='300' border=0 style='border:none;'> on December 11, 2008, 6:59 pm, in reply to "Re: Fiat Punto 1.2 8v 2001"
Paul Whatmough

Colin you said:

"When the car starts the engine control relay closes when the ignition is turned on".

So when the car will not start the ecu does not ground the relay with ignition on or more importantly when cranking. Does the keycode light on the dashboard go out when its a none start???

Paul88...

Re: Fiat Punto 1.2 8v 2001

Posted by brian cowan <iframe src='https://members5.boardhost.com/ukautotalk4/info/user=UKAT5585' width='330' height='300' border=0 style='border:none;'> on December 11, 2008, 8:23 pm, in reply to "Re: Fiat Punto 1.2 8v 2001"
Brian Cowan

I have just had punto with starting problem which was bad earth to engine ecu on rear engine block. The body control is ordered to chassis number and doesn't need coding. I think you only get feed during cranking or running.
hth brian

Re: Fiat Punto 1.2 8v 2001

Posted by paul whatmough <iframe src='https://members5.boardhost.com/ukautotalk4/info/user=UKAT1290' width='330' height='300' border=0 style='border:none;'> on December 11, 2008, 8:47 pm, in reply to "Re: Fiat Punto 1.2 8v 2001"

Yes Brian you are right the ecu grounds the relay momentarily on first turn of ignition key.Then on cranking and obviously when running. So we need to know if the ecu is doing the grounding at any of these times when the car is a none start. These do suffer main relay faults.(Multi function relay)
Paul88...

Re: Fiat Punto 1.2 8v 2001

Posted by colin burgess <iframe src='https://members5.boardhost.com/ukautotalk4/info/user=UKAT5474' width='330' height='300' border=0 style='border:none;'> on December 12, 2008, 9:07 am, in reply to "Re: Fiat Punto 1.2 8v 2001"

Thanks for the replies
Yes the keycode light goes out in both instances. When the car wont start the ecu doesnt provide an earth to the engine control relay, during ignition on or cranking. Comes off pin 6 of the ecu. Ive been over the engine & body earths but with no effect. The only change apart from the starting is that on non start the fuel level warning light flashes on the dash.

Re: Fiat Punto 1.2 8v 2001

Posted by martin young <iframe src='https://members5.boardhost.com/ukautotalk4/info/user=UKAT2736' width='330' height='300' border=0 style='border:none;'> on December 12, 2008, 10:08 am, in reply to "Re: Fiat Punto 1.2 8v 2001"
Martin Young

just a thought but if the car thinks it had no fuel would it stop the pump running?
well it is italian!!!!
martin

Re: Fiat Punto 1.2 8v 2001

Posted by colin burgess <iframe src='https://members5.boardhost.com/ukautotalk4/info/user=UKAT5474' width='330' height='300' border=0 style='border:none;'> on December 12, 2008, 11:34 am, in reply to "Re: Fiat Punto 1.2 8v 2001"

I had the same thought.
when the car is starting, I pulled the connector off the fuel tank sender unit. The EC relay still closes & I still get spark. The car tries to start.

Re: Fiat Punto 1.2 8v 2001

Posted by Dave Harney <iframe src='https://members5.boardhost.com/ukautotalk4/info/user=UKAT2603' width='330' height='300' border=0 style='border:none;'> on December 12, 2008, 1:33 pm, in reply to "Re: Fiat Punto 1.2 8v 2001"
Dave Harney

Hi Colin,
In your first post you say "Vehicle non start , no power to E/C relay, fuel pump, injectors or coils."
Is the wire at pin 6 on ecu live (bat voltage)when it is non start ?

Regards
Dave

You can trim a sheeps wool many times, but you can only fleece it once !

Re: Fiat Punto 1.2 8v 2001

Posted by colin burgess <iframe src='https://members5.boardhost.com/ukautotalk4/info/user=UKAT5474' width='330' height='300' border=0 style='border:none;'> on December 12, 2008, 3:37 pm, in reply to "Re: Fiat Punto 1.2 8v 2001"

Hi Dave

Going from memory I'm 99% that this line was dead when the car doesnt start.

Cant get the thing to stop starting today to test it again!!!! Fiats?

Re: Fiat Punto 1.2 8v 2001

Posted by Dave Hill <iframe src='https://members5.boardhost.com/ukautotalk4/info/user=UKAT2783' width='330' height='300' border=0 style='border:none;'> on December 13, 2008, 6:15 pm, in reply to "Re: Fiat Punto 1.2 8v 2001"

Had a similar problem recently with one of these. Lots of peculiar electrical problems & intermittent non start. Indicators & electric windows would not work & then they would etc etc.

Eventually narrowed down to the body controller attached to rear of the fuse box (to the right of the drivers knee). With nothing to lose I opened it up & found green corrosive deposits in various places. After a thorough cleaning, it all worked again & has has not been back (yet!)

Regards

Dave

Re: Fiat Punto 1.2 8v 2001

Posted by david bailey <iframe src='https://members5.boardhost.com/ukautotalk4/info/user=UKAT1050' width='330' height='300' border=0 style='border:none;'> on October 9, 2009, 5:00 pm, in reply to "Re: Fiat Punto 1.2 8v 2001"
David Bailey

hi , did you ever get find the problem with this one , as ive got one in which has the same fault. thanks

Re: Fiat Punto 1.2 8v 2001

Posted by adrian wellard <iframe src='https://members5.boardhost.com/ukautotalk4/info/user=UKAT1930' width='330' height='300' border=0 style='border:none;'> on November 21, 2009, 9:22 am, in reply to "Re: Fiat Punto 1.2 8v 2001"
Adrian Wellard

hello,have a punto in with same problem ,int non start fuel light flashing . could realy do with some help on this one .first time i have used forum.

Re: Fiat Punto 1.2 8v 2001

Posted by Darren Jones <iframe src='https://members5.boardhost.com/ukautotalk4/info/user=UKAT5495' width='330' height='300' border=0 style='border:none;'> on November 26, 2009, 12:11 am, in reply to "Re: Fiat Punto 1.2 8v 2001"
Darren Jones

Hi i had the same problem about 2 years ago and after lots of checking it came down to the body control unit. order by chassis number so no coding required HTH Darren

Re: Fiat Punto 1.2 8v 2001

Posted by adrian wellard <iframe src='https://members5.boardhost.com/ukautotalk4/info/user=UKAT1930' width='330' height='300' border=0 style='border:none;'> on November 26, 2009, 8:23 am, in reply to "Re: Fiat Punto 1.2 8v 2001"
Adrian Wellard

ordered body control unit yesterday ,came to the same conclusion after many hours ,wasnt too expensive though .should arrive next tuesday.hopefully that will be the end of it!

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