P0400 EGR Flow error

[dransfield]

Hi All

I am a little stumped by an P0400 egr error, and so am reaching out to the community to see if anyone has experience similar and solved

I have a 2008 T25 Avensis 2.2 that has done approx 70K mile

The turbo charger failed recently and was replaced..... all seemed fine until I interfered!

As most of the engine oil had been sucked through the exhaust, and because it had probably never been done anyway, I decided to do a bit of 'preventative' maintenance and clean the egr valve, pipe and manifold - it was pretty bad in there.

The P0400 error started after I did this.

I replaced the EGR valve just in case, still get error. Took it to my local garage who did a thorough clean of the manifold and replaced the egr valve again (!) as they said they my replacement wasn't operating correctly (but I do trust them). Still get the error.

MAF & MAP sensors seem to be fine as is the MAP sensor filter - have also checked the pipe is clear from the MAP into the inlet manifold. Electrical connectors seem clean.  Main air filter has also been replaced.

Idle seems fine, however I do get lumpy acceleration, and if I drop the clutch and give it a good rev a pretty decent black cloud comes out of the back - and leaves a line on the road! - which seems to clear things for a while - Am I right in thinking that if it's black it's unburnt diesel?

I can reset the error and the car will run for about 7 minutes (is this period of time significant?) before the MIL lights come on

 

Thanks in advance

 

 

 

[jcps001]

I'm not sure, but when you replace the EGR you must program something into the ECU... Please wait for someone to confirm this. I don't think that EGR replacement is a "plug and play" job. You have to do something to the ECU aswell.

[dransfield]

Thanks for the suggestion, this was also a theory from my local garage. 

Although I was getting this error with the original egr in place.

 

[Fers]

Not sure 100%, but I think even if you clean the old valve, the position of the flap is not at the position where the computer thinks it is. When build up is on the manifold/flap, computer adapts slowly to this, and it knows the flap position. And when you cleaned it, ECU thinks theres something wrong with it and gives you a error and a faulty fuel/air mixture.

After cleaning/replacing, need to calibrate with a scan tool to tell ECU (or which component controls EGR), that here is new EGR, and make new "zero" calibration, so the computer knows where it is, and what is the flap limit.

[DerekHa]

Agree with Fers on the above.

Had to have this recalibration done after replacing the old egr valve with a new one on my daughters Renault Scenic and it was still giving codes some years ago now. Found a mobile autoelectrician who knew what he was doing and he got the new valve recognised by the ecu. The EML went off and stayed off afterwards. Who ever does this will need the right software by the way.

 

[Fers]

10 minutes ago, DerekHa said:

Agree with Fers on the above.

Had to have this recalibration done after replacing the old egr valve with a new one on my daughters Renault Scenic and it was still giving codes some years ago now. Found a mobile autoelectrician who knew what he was doing and he got the new valve recognised by the ecu. The EML went off and stayed off afterwards. Who ever does this will need the right software by the way.

 

Correct. Not all scan tools are able to do this, additionally different manufacturers of scan tools, have theyr own database of supported vehicles/features.

Only software that I know, will work 100% for Toyota is the good old "TechStream"