EGR Fault code P0403 won't clear

[darrenjane]

My 2011 180 developed a flashing coil light and went into limp mode. Fault code was P0403 EGR Fault. I replaced the EGR valve with a new genuine part - existing was heavily coated with carbon and seized. In addition the flap valve in the EGR cooler was also seized open. I have managed to free this, so it operates under the vacuum pressure.

Rebuilt everything, plugged in VCDS and cleared the fault - engine ran fine with no faults until I took for a test spin. On the first hill the coil light started flashing and now back in limp mode. Now whenever I clear the P0403 fault code on VCDS it instantly returns on startup.

Any ideas on possible cause/ solution gratefully received.
Darren

 

[mrcheesbrough]

My 2011 180 developed a flashing coil light and went into limp mode. Fault code was P0403 EGR Fault. I replaced the EGR valve with a new genuine part - existing was heavily coated with carbon and seized. In addition the flap valve in the EGR cooler was also seized open. I have managed to free this, so it operates under the vacuum pressure.

Rebuilt everything, plugged in VCDS and cleared the fault - engine ran fine with no faults until I took for a test spin. On the first hill the coil light started flashing and now back in limp mode. Now whenever I clear the P0403 fault code on VCDS it instantly returns on startup.

Any ideas on possible cause/ solution gratefully received.
Darren

Sounds like fun. This website suggests it may actually be your N18 valve that has a fault rather than the physical EGR valve itself. Although it sounds like you may of dealt with something that could of caused the N18 to fail.

 

[darrenjane]

hi mrcheesbrough
Thanks for that - yes the fault does refer to N18. I thought this was the actual egr valve. I’ll investigate further to find the N18
Thanks
Darren

 

[mrcheesbrough]

hi mrcheesbrough
Thanks for that - yes the fault does refer to N18. I thought this was the actual egr valve. I’ll investigate further to find the N18
Thanks
Darren

No problem. I hope it goes some way to helping sort the problem. The N18 valve has vacuum pipes running off it to the EGR valve. It’s similar to the N75 which controls the turbo side of things. I believe the N18 would actuate the previously seized flap you mention. From what I’ve read the flap seized open is not a good thing. Closed is less of a problem as it doesn’t flood the combustion chambers with exhaust fumes.


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[darrenjane]

Hi mrcheesbrough
Many thanks for your reply/ advice on this, very useful. Van ended up going to local VW dealer who redid all the basic settings and synced the new egr valve, but still had the fault/ EML. They carried out leak tests on the egr, cooler and vacuum and all was good. They redid all basic settings again and managed to clear the fault. Vehicle has had 10 mile test run without the fault/ EML. So, fingers crossed it’s ok now.
Regards
Darren

 

[mrcheesbrough]

Hi mrcheesbrough
Many thanks for your reply/ advice on this, very useful. Van ended up going to local VW dealer who redid all the basic settings and synced the new egr valve, but still had the fault/ EML. They carried out leak tests on the egr, cooler and vacuum and all was good. They redid all basic settings again and managed to clear the fault. Vehicle has had 10 mile test run without the fault/ EML. So, fingers crossed it’s ok now.
Regards
Darren

My fingers are crossed for you too. Shame it wasn’t a more simple issue but it sounds like the dealer did a thorough job working the issue out. Happy camping.


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