P0402 Excessive EGR flow error

jtmgrfx

Member
Joined
Mar 31, 2005
Location
Attleboro, MA
TDI
2001, Dk. Blue
Hello:
I am trying to solve my problem check engine light. I am getting a P0402 code "excessive EGR flow". I just replaced the egr valve today. I had also changed the glow plugs because I had that error prior to this latest one. The code came back on. Do I need to now change the pressure converter for an A4? The mechanic I'm working with is unformiliar with the tdi, but is honest in helping me solve the problem. He replaced the valve today and cleaned and vacummed the line. The light was off until I was a few miles onto the highway. I'm running a 2001 TDI with 100,000 miles as of yesterday.
Thanks!
 

jtmgrfx

Member
Joined
Mar 31, 2005
Location
Attleboro, MA
TDI
2001, Dk. Blue
Thanks. I read your information and it talks about a DPFE sensor and I can't find any information about one in the TDI.
 

DieselFumes

Veteran Member
Joined
Oct 18, 2002
Location
Greenwood, IN
TDI
2002 Jetta TDI
How about the EGR frequency valve? There should be a diagram just above the radiator near the battery that will help you locate it.
 

DieselFumes

Veteran Member
Joined
Oct 18, 2002
Location
Greenwood, IN
TDI
2002 Jetta TDI
Well, I'd check the vacuum line going from the EGR frequency valve to the EGR. I'd also make sure that the electrical connection on the EGR frequency valve is corrosion free and snugly connected. I don't know how one would test the EGR frequency valve, though.
 

jtmgrfx

Member
Joined
Mar 31, 2005
Location
Attleboro, MA
TDI
2001, Dk. Blue
I just received and changed the pressure converter.The light initially came on, but now is off. I ran the car around town and remains off.
Now, I just need the computer reset so I can go get my car inspected. Anyone know of a franchise who'll reset it for me for little $$$. I know others charge $25 and up? My mechanic has done it for me in the past, but is now a 45 mile drive each way.
 

DieselFumes

Veteran Member
Joined
Oct 18, 2002
Location
Greenwood, IN
TDI
2002 Jetta TDI
The pressure converter, is that the same as the EGR frequency valve, or some other part? If some other part, how did you determine that it needed replacing?

As for resetting you computer, I would think that since the Check Engine light isn't coming on that it should pass inspection. If there is a local Autozone you could have the check the computer for codes and when they find some ask them to reset it so you can drive around and see if they come back. I've had them reset codes and they've never charged.
 
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