Technical P2146 ECU faulty

[Bellitito]

Hi All,

I am rather new to this form. I have a Fiat Punto Evo 1.3Mjet from 2010 with 188K KM. Recently I have had the engine management light popping up on the dashboard. I have noticed that after several engine restarts the engine management light vanishes. Now and then the engine management light pops up again...

Read out shows fault P2146 to be "pending". In other words it is not always present? Anyhow i have loss of power, no cruise control and start stop.. I guess this is the aftermath of the car going in the "Emergency running" (hope i am using the right wording here).

I have had my car checked at the garage and they have checked the injectors, wirings and connectors. All are OK. The garage told me that the warning could be related to the ECU but as the error is not always present the mechanic was not sure. I have come across several forums on the internet indicating that replacement of the ECU repaired this issue.

My guess is that the capacitors are faulty on the printed wiring assembly of the ECU. I was hoping someone could share the schematics of the ECU so that I can replace the faulty capacitors. Can someone help me out? I tried searching the internet but no luck here....:bang:

Thanks.

 

[varesecrazy]

Hi

The code is not an ECU codr.. but a bad connection

https://www.fiatforum.com/grande-pu...o-response-gas-pedal.html?434468=#post4146856

 

[Bellitito]

Hi,

I have read that thread previously but we have checked all the connections and everything was ok... Previous Punto Evo 1.3mjet drivers have reported that replacing the ECU solved the issue. Do you by any chance know where i can get the schematics?

 

[varesecrazy]

Are you using FIAT specific diagnostic software?

We see a lot of erroneus codes reported on here.. from VAG kit

 

[AndyRKett]

Hi,

I have read that thread previously but we have checked all the connections and everything was ok... Previous Punto Evo 1.3mjet drivers have reported that replacing the ECU solved the issue. Do you by any chance know where i can get the schematics?

If you are just replacing like for like components then why do you need Schematics ?

Honestly It can easily be a poor connection hence why its intermittent. If it where faulty caps it would be a pretty permanent issue.

Good luck working on modern car engine ECU's if you don't destroy it trying to get in (I believe the fiat fire units are fully potted) then you'll probably wreck it trying to get the components out.

Far easier and cheaper to buy a replacement ECU if you think that's the problem, they're not that expensive these days.

 

[Bellitito]

Since i cant use the reply button yet:

Yes Fiat diagnosis software was used and the garage previously checked the wiring connections manually.

I have managed to get the out the printed wiring assembly but it was a more difficult task than I thought. We did not find anything that was obviously defect (such as a leaking component) but one of the 2700 uf 35v capacitors was far below the +-20% requirement (measuring 1700 uf instead of 2700 uf).

I also noticed that the part where the connector fits on the ECU was a little dirty.. i cleaned the connector and ordered new capacitors. I will keep y'all posted...

In order to perform further troubleshooting on the ECU PWA I do require the schematics.

 

[SRafferty]

I would check if cam position sensor also, as it could be that the engine speed signal is erroneous. You should be able to do this on diagnostic. Could be a long haul. Good luck.

 

[Bellitito]

I have purchased a second hand ECU and got it to a car electronics shop that managed to make the ECU "virgin" and stored my injector codes. I've fitted the ECU yesterday and it seems that P2146 is solved for now.

However, during cold start i still find the engine running raw, reving between 800 -1200 RPM during idle and only when starting to have blue smoke. This all happens only when I have a cold start, everything is ok when the engine is warm.

A cylinder correction read out shows the following:

Cyl. 1 fuel correction: -2.16 mm3/inject
Cyl. 2 fuel correction: 1.19 mm3/inject
Cyl. 3 fuel correction: 0.71 mm3/inject
Cyl. 4 fuel correction: 0.77 mm3/inject

Does anyone know what these values mean? What values should I measure during normal circumstances?

Thanks.