Technical Limp Mode again and again and again

[tezzler]

We have a 2009 1.3 diesel Multijet Pop. About 18 months ago it started to periodically go into limp mode with two engine codes PO402 and PO401.
To date we have changed : -
Diesel Particle Filter ,
DPF temp sensor,
DPF sensor ,
Map sensor,
Cleaned the EGR Valve and all pipes

And yes it's still doing it

Has anyone any ideas? We are totally at our wits end.
Thanks

Terry

 

[tezzler]

We have a 2009 1.3 diesel Multijet Pop. About 18 months ago it started to periodically go into limp mode with two engine codes PO402 and PO401.
To date we have changed : -
Diesel Particle Filter ,
DPF temp sensor,
DPF sensor ,
Map sensor,
Cleaned the EGR Valve and all pipes

And yes it's still doing it

Has anyone any ideas? We are totally at our wits end.
Thanks

Terry

Anyone?? We are desperate to find an answer

 

[The Panda Nut]

Do you have an ehaust gas recirculation valve on your car. I have had issues with the EGR Valve on two other diesels ( including a Fiat 1.6D) causing limp home. P0402 and 0401 does suggest this. Google the iuse of EGR cleaner and try using this but watch a video on how to do it and squirt in small shots or it can have a nast effect on the engine causing it to stop dead with possible bad side effects.

Worth trying cleaner, but my experience is to just buy a new EGR valve for a permanent fix. When done use diesel fuel teratment like Wynns every few tanks of fuel, to reduce the carbon build up.

My experience has been EGR's last about 40, 000 miles before playing up. Fiat parts are not badly priced for these things.

 

[tezzler]

Thanks so much for the reply, so a change of EGR valve is definitely worth it as its the original valve and the car has done 115000 miles! Thanks

 

[tezzler]

So the EGR valve was changed and yes it still goes into limp mode with P0402
We are now thinking of having the ECU modified to remove the EGR valve.
Has anyone done this?
Thanks

 

[The Panda Nut]

Belatedly Im sorry EGR didnt work for you. I have found that the codes the Fiat cars throw are not always accurate in indicating the fault. Looking on the net there is a suggestion that the DFP may be cracked allowing soot pass through and to mess up the EGR, hence a viscious circle. This might be one where a dealer diagnosis culd be worth a try. The net comment suggested if the exhaust is sooty when you rub a finger in it its also a sign of DPF issues, though with a diesel even with a DPF im not so sure. I have found that while expensive dealer diagnostics by a decent tech reveal more than my MES for example.

 

[tezzler]

We did have the DPF changed as well together with all sensors. Dealer is cost prohibitive as we are in France
Cheers

 

[jackwhoo]

.

 

[jackwhoo]

EGR P0401 P0402 1.3 diesel: some answers.

Thread title is very similar to your problem s that was resolved

 

[tezzler]

I actually read that before posting. We now have a new EGR valve. My mechanic connected a laptop and drove the car. The EGR valve lost power when the limp mode came on. We have nothing left apart from the ECU