Engine Fault light with dash Light plus coolant leak

[kingy1912]

Hi all,

Was driving my 16 plate 1.6 blue hdi with no problems last night until I stopped it for a couple of hours. Got back out to it started her up and then had the engine fault warning plus the Check light on dash. Couldn’t do much last night but checked it over today and only visible thing I can see or hear is a coolant leak from under the thermostat housing. Engine runs fine no funny noises no smoke and no difference in fuel usage. Only thing I can see without getting the Citroen codes read is the coolant. Just wondering if anyone things this coolant leak could be the cause of the light somehow??

Thanks

[kingy1912]

Managed to get my hand held code reader from garage it has codes U029D and P2200 pertaining to NOx Sensor and communication. Not sure if that and coolant are related or just coincidental. I managed to erase the codes and reset the check light so will drive it again and see if it comes on again.

With any luck it may just have been a glitch but I suspect at mileage the car has on it (258K) it is probably a failing sensor or faulty wiring.

[kingy1912]

I see there is not much in the way of reply so not sure if anyone has had an issue with this here. However to update the garage has looked at it and the two faults i found above are the only ones they can find on it to. The communications error could be a sensor fault but is usually more commonly a wiring issue. The citroen system has bulletins on it regarding the issue and is seems to be becoming a more common issue reported with the adblue engine. My garage has spoke to the master tech at citroen and he says first place to start is with the sensor as it is the most common issue they are seeing. My garage has also trsted all the wiring they can access without pulling everything apart and all wiring and connections check out ok. This is also leading them in the direction a sensor failure but they cant tell this until they swap it for a new one which is quite costly at £236.

The part will be in tomorrow afternoon and the car should be back tomorrow evening if all goes well so i will update further then and see if it is just the sensor. At the least if no one has had much experience of this issue it may help someone in the future who does.

[kingy1912]

So another update on this issue:

1) the coolant leak seems to be coincidental

2) The NOx sensor has been replaced for a new unit and the fault code and check light is now gone and all running well. The NOx sensor was fairly sooty and a bit dirty but not sufficient enough to be the source of the issue they believe. Also after giving it a clean up the sensor was still showing the fault. It would appear that this is just one of these common issues that are found in this engine model.

[katyjohn]

Hey,
I found a blog related to these error codes that can might help you to find the real cause. Take a look at it
https://xenons4u.co.uk/blog/u029d-and-u0...explained/

[geoff]

Thanks for the update !

[polar]

Hey,
I found a blog related to these error codes that can might help you to find the real cause. Take a look at it
https://xenons4u.co.uk/blog/u029d-and-u0...explained/

no one is going to follow a link from a one time poster mate

[kingy1912]

The link only tells you what they do where to find them and the common issues. The all wiring and voltages were checked which was the reason the new one was ordered. 6 months on and about 22k later everything is fine with it.

[kneadman]

The link only tells you what they do where to find them and the common issues. The all wiring and voltages were checked which was the reason the new one was ordered. 6 months on and about 22k later everything is fine with it.

Thanks just had the same issue with 2016 berlingo multispace...