Toyota Avensis EGR Issues

[v8s4me]

I have a 2006 Avensis with the 2.2D-4D engine with 100K miles on it. Just recently I've been getting the MIL light come on with the VSC & TRC lights. The OBD2 reader tells me the error code is P0400 which relates to the EGR flow, not the braking system. I've cleaned the EGR, which was filthy, and cleared the codes by disconnecting the battery.

Everything is fine for a few miles then the lights come on again with the same error code. Sometimes the lights go off again after a few more miles and then come back on a few days later.

I've also tried clearing the VSC & TRC lights by using the trick of jumpering the 4th & 13th pins on the OBD socket and tapping the brake 8+ times. This works for a while and then the lights come back on again with the P0400 error code.

The car is running fine with no apparent issues. Anyone have an idea what might be going on here?

It's been suggested that I fit an EGR blanking plate. Is there anything to gain by this? Will the ECU throw up more errors codes if I fit one?

Thanks in advance?th

[Little Pete]

The two most common faults relating to EGR flow are the valve being stuck or not moving fully through it's operating range. Secondly the valve not sealing when it is in the closed position. The latter is easy to check, just take the valve off and pour or spray some fluid in and see if it leaks past the seat. To test the former you will need a diagnostic tool that allows you to test the valve operation. Most vehicles need the EGR valve mapping out if it is blanked off. In my experience it is easier to fix the fault.

[v8s4me]

Little Pete said:

The two most common faults relating to EGR flow are the valve being stuck or not moving fully through it's operating range. ...

I've checked the seating for leaks one way or the other but I've not yet checked to see if the valve moves freely over its full travel.I suppose it's always possible it is stuck closed. Would that cause the symptoms I have?

Thanks for the suggestion.

[Little Pete]

Sorry for the delayed response. Yes if the valve is stuck in any position it will trigger fault codes. Did you clean the valve thoroughly and did you clean the manifold?

[v8s4me]

No problem, thanks for the response.

The ports in the manifold were very clogged and only the large centre one was allowing any gas flow at all. I gave that a through clean out and opened up all three ports. I didn't have a "star head" socket large enough to remove the servo off the back of the EGR valve so I was only able to clean it in the closed position. Both chambers are now thoroughly clean, and I know there is no leak between the inlet and outlet side, but of course I don't actually know if it opens, and if it does, how smoothly.

[v8s4me]

I cleared the fault code and removed the EGR again today. This time I stripped the motor off and cleaned the poppet valve thoroughly. I'm now confident that the valve moves smoothly through it's full range and seats/seals as it should. Of course the motor may be faulty but I'm not sure how to check that. Anyway, a couple of runs this afternoon/evening getting it up to full temperature and so far so good. Fingers crossed.