I recently purchased a Punto 1.2 ELX 2001 reg. and it has developed the following problems:-
Speedometer only goes up to around 20mph max and does not give accurate reading at lower speeds.
ABS light does not come on and go off when ignition is turned on.
Car has had a new ABS unit fitted - not sure when. Took it to a local Fiat specialist who could not log onto the ABS system to get a reading, apparently it crashed his computer even when he turned wheels by hand??
We plugged in another ABS unit earlier today, same result no ABS light.
Could the problem lie with the ECU connection???
Struggling to know were to look next
Any help would be appreciated

do you know history of the car?
ie has it had the fuse box and bsi unit behind the dash changed lately?
is the abs unit off the same year car?
have you checked the abs sensor on the n/s wheel and also the wiring and plugs up to the abs unit
is the multiplug in the abs unit properly?

Hi, no I don't know the history, person I bought it from was a bit economical with the truth - which I have found out to my cost!!
I think the ECU may have been changed because the car was supplied with 2 keys, one for the door and one for ignition.
The new ABS unit I tried earlier today was from the correct model, but no joy with repair e.g. same fault indicated, no ABS light.
All plugs seem to be fully located.
I will be more careful next time I buy, but apart from this fault car is pretty good.
Cheers for response
Taylorhogg

hi
sorry been messing with linux
i think your man has fitted a non bsi unit to your car and this is why it wont talk to the abs
i cant be sure and if seller is being obtrusive you have a bit of a problem im afraid
where are you?

Hi I live in Verwood nr. Ringwood (Hampshire), but car is for my son who is at College near Sheffield and is due to go back in a couple of weeks.
I notice there are a lot of ECUs for sale on Ebay, would it be worth trying one of those?
Thanks for support
Regards

taylorhogg said:

Hi I live in Verwood nr. Ringwood (Hampshire), but car is for my son who is at College near Sheffield and is due to go back in a couple of weeks.
I notice there are a lot of ECUs for sale on Ebay, would it be worth trying one of those?
Thanks for support
Regards

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unfortunately not
even my local breaker got confused with these so most people on the bay wont sell you the right one
its especially difficult now because your car doesnt even have the numbers on the bsi to compare with
i might of course be wrong in my prognosis its just ive been experimenting lately and your problem does seem to fit the bill

i really dont know what to suggest because the speedo is connected to the abs so you couldnt even go down the route of disconnecting it,the giveaway is that you say no light on the dash
try asking seller for old fuse box if this is what he has done and i might be able to help you locate a replacement
there is an ecu on the abs isnt there?i have one of those at work im sure

I think there is, but we did try plugging in a complete new ABS unit earlier with no change in fault, so I think it all points to the ECU behind fuse box.
I don't suppose main dealer would be able to provide correct numbers from VIN codes?
Thanks

The speedo problem is probably the speed sensor on the gearbox. This won't be linked to the ABS computer on a 2001 model but is linked to the power steering ECU.
If you pull the main ABS fuse then the light should come on.

I thought on models with abs speed was calculated from average of all 4 wheel sensors?
Will try pulling fuse just to check
thanks

taylorhogg said:

I thought on models with abs speed was calculated from average of all 4 wheel sensors?
Will try pulling fuse just to check
thanks

Click to expand...

it is
as far as im aware it just reads the front one though
the giveaway for you is no speed sensor on the gearbox,of course having bought a pig in a poke the gearbox might have been changed too and it might have one with no wires attached

any luck getting info off seller yet?

How about getting a full electronics set from one car? Engine ECU, body computer, immobiliser, keys (anything else?).

WhiteSei said:

How about getting a full electronics set from one car? Engine ECU, body computer, immobiliser, keys (anything else?).

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thats the answer so long as its same model with same extras and one that doesnt need cam sensor if this car hasnt got one, but we arent sure it would solve the problem because the cars been bastardised

speedo head too from same car needed or it will wink at you all day

taylorhogg said:

I recently purchased a Punto 1.2 ELX 2001 reg. and it has developed the following problems:-
Speedometer only goes up to around 20mph max and does not give accurate reading at lower speeds.
ABS light does not come on and go off when ignition is turned on.
Car has had a new ABS unit fitted - not sure when. Took it to a local Fiat specialist who could not log onto the ABS system to get a reading, apparently it crashed his computer even when he turned wheels by hand??
We plugged in another ABS unit earlier today, same result no ABS light.
Could the problem lie with the ECU connection???
Struggling to know were to look next
Any help would be appreciated

Click to expand...

hi there, I've just bought the same car and got the exact same problem, im just wondering if you got to the bottom of the problem?