tomwilliams10
29-05-2012, 07:35 PM
Hi all,
I've been having problems with my 08 A5 3.0tdi (CCWA). EML light came on for first time about 3k miles ago, code was P0401 EGR insufficient flow. I cleaned out both lower manifolds, the upper one and the throttle valve. All was good until about 500mile ago when the same code was thrown.
Took off EGR valve, had carbon build up on it, but not much. EGR cooler felt fine (could only feel past bypass valve inside).
Hooked it up on way to work this morning and took measurements of EGR Valve actual, feedback and output stage. Here's a freeze frame of the result. Are the actual and feedback figures supposed to match (like the throttle control ones do?). If so, then i reckon i found the issue...
9:36:12
644.2 mg/stroke Actual air mass 002
20.79 % Air conditioner fan activation 003
18.68 % EGR valve activation 017
81.54 % EGR valve feedback 018
-4.05 % EGR valve output stage 019
11.79 % Throttle valve feedback 070
12.38 % Throttle valve activation 071
15.27 % Throttle valve output stage 072
63.88 % Intake manifold flap activation 081
What do you guys think?
I've been having problems with my 08 A5 3.0tdi (CCWA). EML light came on for first time about 3k miles ago, code was P0401 EGR insufficient flow. I cleaned out both lower manifolds, the upper one and the throttle valve. All was good until about 500mile ago when the same code was thrown.
Took off EGR valve, had carbon build up on it, but not much. EGR cooler felt fine (could only feel past bypass valve inside).
Hooked it up on way to work this morning and took measurements of EGR Valve actual, feedback and output stage. Here's a freeze frame of the result. Are the actual and feedback figures supposed to match (like the throttle control ones do?). If so, then i reckon i found the issue...
9:36:12
644.2 mg/stroke Actual air mass 002
20.79 % Air conditioner fan activation 003
18.68 % EGR valve activation 017
81.54 % EGR valve feedback 018
-4.05 % EGR valve output stage 019
11.79 % Throttle valve feedback 070
12.38 % Throttle valve activation 071
15.27 % Throttle valve output stage 072
63.88 % Intake manifold flap activation 081
What do you guys think?