EGR failure and cruise control relationship D40 STX550 V6

[JLA]

I had the aircon compressor replaced. On pickup I was told the EGR valve was reporting errors. I had not noticed any? When I drove home the engine light came on and also the cruise control would not set a target speed.
A day or two later both the EGR and the cruise control were now working normally.
I dropped it into the service guys (non-Nissan). They said there is a temp sensor in the EGR valve. There is a weird fault that stops cruise from working when the EGR valve gets a particular type of fault associated with this temp sensor.
They reset the stuff around the EGR valve and all works but advised that a new EGR valve may be required in the future.
Has any one else experienced this weirdness?

 

[Old.Tony]

Not me but I suspect your car is a little newer than mine (a 2009).

It sounds more like an electrical gremlin at work - it wouldn't hurt to clean and check all battery connections and unplug/replug the EGR connector just to be sure.

 

[Macs550]

It is likely that your egr valve requires replacement. I had the same issue at 99000km. Mine started off as intermittent and then got to the point where it would not clear. I removed the egr and cleaned it up but had no success. Nissan wouldn't warrant mine because I have a chip. Anyway, the problem was a faulty egr valve. Mine is a 2012 and from memory pre 2013 had this problem. There is an old thread explaining it. I think it was mentioned that Nissan would replace the valve and upgrade the ecu software.

Before committing to replacing, I would check it isn't clogged up first. If it is blocked or heavily restricted you will have the same problem. I used to have an egr blanking plate in mine. I had to drill an 8mm or thereabouts hole in the plate so as not to create this ecu error. Because the egr blanking plate hole was only just bigger than the restriction required to trigger an ecu fault I found that I had to remove the plate and clean the hole periodically. If you haven't had the car since new then maybe check there isn't a blanking plate installed by the previous owner also.

I ended up removing the egr blanking plate. While it did make the car a little more responsive, i found it messes with the boost control under partial load on hills creating compressor surge under certain conditions.

Any time you get a fault due to egr then the cruise is disabled. It's like Nissan's way of telling you there is a minor problem and get it checked.

Andrew

 

[JLA]

That’s very interesting. I wasn’t sure if I was being told the truth or not but your response confirms it’s all true.
I have had the D40 (2012) from new (108,000klm).
I have been tempted to add the blanking plate a few times but held off. Each time I have it serviced, post warranty, they squirt some cleaner in there. So it appears the valve is fairly clean but nearly at life end.

Also tempting is the electronics that plugs into the EGR valve taking the place of the blanking plate. Normally when the EGR valve is told to move to a certain position the EGR valve moves and returns it’s actual position. If the two don’t match, that’s an error. I imagine that this inserted electronics simply echos back the position it’s told to go to but keeps the EGR valve closed off full time. It seems this system would have the same disadvantages of the blanking plate. I think it also warns that this electronics won’t fix a faulty EGR valve fault. It could get complex but it can easily be unplugged for fault finding unlike the plate.

The question is do I have to take the vehicle to Nissan to have the EGR valve replaced because it may also need firmware upgrade that may not be possible elsewhere?

I notice the valve on eBay is less than $500. The valve is a grand from Nissan. The eBay claim it is original, any thoughts.? Also a gasket is required. I confirmed with Nissan that there is only one part number for the STX550 valves regardless of year.
i am tempted to get the eBay “genuine” one and replace it myself.

 

[Macs550]

If it was me I would buy the one from ebay and fit myself. It is quite straightforward. Maybe contact nissan and see if there actually is a software upgrade required.

I have one of those electronic egr jump cables. I used it for a while after I removed the blank plate. It goes between the MAF sensor and the sensor plug. I had no faults with it other than what I mentioned earlier about the compressor surge in 7th gear on hills. Same as with the blanking plate. I prefer to just let the egr do its thing now.

What failed on your accompressor? I had the ac clutch coil burn out at about 120000km. I was able to just buy the ac clutch pulley assembly from Nissan. With a bit of patience I was able to replace the ac clutch pulley without removing the radiator or fan.

 

[JLA]

As the EGR valve part number is the same for all STX550’s according to Nissan, I will assume no firmware upgrade is required. I agree that the eBay option is the best, now I know the task is not very involved.

Spot on with the aircon compressor. It was just the coil but the compressor was swapped out. Wish I’d known the clutch coil was available beforehand.

Thanks for all the help!