Technical Fiat Punto MK2 p0352 ignition coil B primary/secondary circuit

[wabo]

Hi all,

For a long time now (over a year) i have the check engine light coming on and off with error code - p0352 ignition coil B primary/secondary circuit.
At first it had no effect at all and would happen every few weeks, and just went off after a few restarts.
After a while (several months) two of the cylinders misfired for a couple of seconds, and then came back on. This would happen when the car was idle, with A/C on and the radiator at max power.
The problem became more severe over time, and would occur for whole minutes, even on higher RPMs (but still correlating with radiator on max power & A/C).
I have switched between the ignition coils, which made the issue go away for about 24 hours before it came back. Error code is still for coil B.
I plan to change the spark plugs anyway (regular maintenance), but I suspect the problem is with the ECU.
So basically what gave me that idea is the fact that when I clear the fault code while the cylinders are misfiring, they go on and off for as long as the clearing process continues. Sometimes clearing the fault code even causes the cylinders to fire normal again for a good while.

I'm looking for suggestions about what my next steps should be, considering that this issue has already become kind of bothering for daily driving.
I would appreciate any ideas and inputs.

 

[s and b]

worth noting that the plugs from ecu that go into coil pack can sometimes become intermittent due to age wibbly/ wobbling

 

[dasiygtv]

Have you tried a different set of ign coils ?

 

[Niklazo]

I have similar problems with my car. Did you find any solution to it?

 

[Mike1alike]

I had recently the same problem, just on the coil no. 1, error P0351. It seems that I've sort it out and was not the ECU, but resistance on the wire ECU to coil. I will open a new thread about it soon with more details. Now I am still keeping it under observation, so far all is good, the problem did not popped up again. What I did was cleaning with contact spray the left hand side plug (as looking to the car from the radiator, the side with larger width between ECU's bolts) that connects to ECU and cleaned the pin no. 38 on that side on the ECU. The coil no. 2 pin is pin no. 10 on the same side, on ECU.

 

[Mike1alike]

No, I take that back.
The "fix" mentioned above lasted 2 days.
So it turns out it is ECU malfunction that's causing the problem.
I've got another ECU, second-hand, and now the engine is running great.