Seems to be alot of posts concerning the punto ECU/coil failures & new members to the forum unaware of what the search button is for
So here goes...the 'definate' guide to the great punto ECU/coil failure!
SAFETY...high voltages involved people so be careful
(1)First thing to establish is which coil is not firing,
Easily done,simply disconnect the 2-pin connector on either one of the coils & try to start the car...if it still runs(a.k.a. like a bag of s*it)then the coil you have disconnected is the one not firing.
If it does not start then the one you did not disconnect is the one not firing....simple
(2)Is the coil or ECU at fault?
Bit trickier but not exactly rocket science! After determining which coil is not firing(see step 1)disconnect the 2-pin connector on that coil(if not already done so)it helps if you remove the little yellow plastic cover at the end of the plug as it makes 'probing' the terminals abit easier.
You will need prefably a test light or a power probe.I have never tried it with a multimeter as I doubt they(either LCD or needle type) will be fast enough to sense the negative trigger.
One of the 2 terminals should be live(12V+)only with the engine running,make sure you refit the 2-pin connector on the good coil.
On the other terminal(again engine running)you should have a negative(12V-)trigger/pulse,you can test this by putting the test light clip onto the 'positive' battery post(thus it will light up when earthed)& the bulb should flicker very fast & 'uniform',if it does(& the plugs/leads are OK)then you need a coil.If it does not light up then the ECU is not sending out a negative trigger & you need a ECU..but first check this wire is ok(no water on ECU plugs) & not shorted out on the throttle cable holder or anywhere else...unlikely but I have seen this a few times.
(3)If the car will not start up then you can still do the above checks on 'crank' assuming you have a assistant/wife/passer-by to crank it over for you.
If you have no 12v+ to either coil then check relay R9 & fuse 22.
And thats it
So here goes...the 'definate' guide to the great punto ECU/coil failure!SAFETY...high voltages involved people so be careful
(1)First thing to establish is which coil is not firing,
Easily done,simply disconnect the 2-pin connector on either one of the coils & try to start the car...if it still runs(a.k.a. like a bag of s*it)then the coil you have disconnected is the one not firing.
If it does not start then the one you did not disconnect is the one not firing....simple
(2)Is the coil or ECU at fault?
Bit trickier but not exactly rocket science! After determining which coil is not firing(see step 1)disconnect the 2-pin connector on that coil(if not already done so)it helps if you remove the little yellow plastic cover at the end of the plug as it makes 'probing' the terminals abit easier.
You will need prefably a test light or a power probe.I have never tried it with a multimeter as I doubt they(either LCD or needle type) will be fast enough to sense the negative trigger.
One of the 2 terminals should be live(12V+)only with the engine running,make sure you refit the 2-pin connector on the good coil.
On the other terminal(again engine running)you should have a negative(12V-)trigger/pulse,you can test this by putting the test light clip onto the 'positive' battery post(thus it will light up when earthed)& the bulb should flicker very fast & 'uniform',if it does(& the plugs/leads are OK)then you need a coil.If it does not light up then the ECU is not sending out a negative trigger & you need a ECU..but first check this wire is ok(no water on ECU plugs) & not shorted out on the throttle cable holder or anywhere else...unlikely but I have seen this a few times.
(3)If the car will not start up then you can still do the above checks on 'crank' assuming you have a assistant/wife/passer-by to crank it over for you.
If you have no 12v+ to either coil then check relay R9 & fuse 22.
And thats it
