Ad blue warning - can anyone give any pointers on the analysed data?
- Thread starter Lucasimo
- Start date
Interesting to note that now it cannot do an SCR metering test (aborted due to safety reasons keeps appearing) and it now keeps producing fault code P218F. It certainly looks like the injector is actually dying or now dead. It has some electronics inside it so I am assuming this does some sort of flow control monitoring. A new injector is arriving on Wednesday so I'll fit it and see where I get to.
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Thank you very much. Attached a graph of active data during the test. The other data didn't change (much) and were within observed values in other logs of normal use.
A kind of interesting thing is that it seems the pump was not driven at max but at very low PWM (now 5% as normally can be seen up to 80%) - perhaps to see that AdBlue is injected also at low end of usage. Likewise the specified quantity (now at steady 4 mg/s as normally up to 220 mg/s have been observed).
The pressure reading is most likely based on pump current measurement (mentioned in SSP 540) so probably - also within observed values.
That's really useful stuff to know. Many thanks for the analysis. Last night I figured out that the injector is actually a solenoid valve and is exactly the same operation as a water treatment chemical dosing pump (handy to have old job experience!). I put 12 volts DC on the terminal plug and the injector clicked operating the valve. It appears to work but looks like it could be temperamental.
My theory is that if it doesn't work when it is commanded to operate, this most likely triggers a fault condition of no flow.
I might do a continuity test of the 2 core cable from the ECU to the injector to see if it's a dodgy cable.
I think I have wiring diagrams somewhere on my laptop showing pinouts of the ECU connector.
Well, the usual indication of "Finished correctly" quite often means only that the ECU was able to perform the test from start to finish - not indicating the system was within specifications. Hence need to set up proper measurements and acceptance criteria using "Show measurement values". "VW ODIS Guided fault finding" has sometimes built-in the acceptance criteria but rarely shows the data itself - perhaps not to let mechanic learn too much of the internals
Yeah. I was certainly sceptical when it said "passed OK"Well, the usual indication of "Finished correctly" quite often means only that the ECU was able to perform the test from start to finish - not indicating the system was within specifications. Hence need to set up proper measurements and acceptance criteria using "Show measurement values". "VW ODIS Guided fault finding" has sometimes built-in the acceptance criteria but rarely shows the data itself - perhaps not to let mechanic learn too much of the internals
Perhaps the first step would be to disconnect the connector at injector and check what/any new fault codes appear - to indicate how an actual disconnect shows up.
So I managed to scan it and a low voltage warning came up. I remember I was doing a lot of diagnostic testing with the van yesterday and I caused the battery voltage to drop quite a bit hence the fault code coming up. It was about 12.09V. It's not a major issue and it will be charged up soon enough.
I realised if you are in the van with the key in position 1 in the ignition it keeps the fuel pump constantly priming. Well, I'm guessing it's that sound I can hear.
No other fault code appeared so I guess the low voltage one might cause other controllers to not communicate.
I realised if you are in the van with the key in position 1 in the ignition it keeps the fuel pump constantly priming. Well, I'm guessing it's that sound I can hear.
No other fault code appeared so I guess the low voltage one might cause other controllers to not communicate.
So I did a scan when the battery voltage had got up to about 13 volts when the engine was off, and then I cleared them and ran the scan again when the engine was idling for about 2 mins. I'm ignoring the low voltage fault as this didn't come back when cleared the first time and it was expected as well.
Both documents are attached. The no flow fault is expected since there's obviously no injector on there. Also an open circuit injector fault appeared which is also expected. So in this sense, the ECU knows there's no working injector connected at the moment. This gives me some confidence that the ECU wiring to the injector is most likely OK. It looks like someone else in the past did some work on the Adblue system since the mounting bracket that holds the Adblue injector didn't have its bolt attached and it was resting on part of the subframe. I had a 8.8 M6 bolt saved from removing the van cab separation panel that happened to fit exactly so I put that in to fix it.
The times on the scan are all wrong as I disconnected the battery for a while last night in an attempt to reset the ECU. It was actually tested at about 4:10pm today in the van.
Both documents are attached. The no flow fault is expected since there's obviously no injector on there. Also an open circuit injector fault appeared which is also expected. So in this sense, the ECU knows there's no working injector connected at the moment. This gives me some confidence that the ECU wiring to the injector is most likely OK. It looks like someone else in the past did some work on the Adblue system since the mounting bracket that holds the Adblue injector didn't have its bolt attached and it was resting on part of the subframe. I had a 8.8 M6 bolt saved from removing the van cab separation panel that happened to fit exactly so I put that in to fix it.
The times on the scan are all wrong as I disconnected the battery for a while last night in an attempt to reset the ECU. It was actually tested at about 4:10pm today in the van.
Whilst doing some more research on this last night I wonder if it needs to have an SCR efficiency test to get it back to normal. The trouble with doing that test is that you have to sit there with brake and accelerator pressed for what might be 30 mins. I expect this is sort of similar to the workout it gets when people say the system resets the top up range countdown once they had driven the van around for a while. All things seem to point towards to just driving it and eventually that stupid little bottle and beep noise will hopefully F off! At least it will have a new injector fitted this week and then it's almost all new parts, except the dosing line. Though to be honest, I can't see any reason at present why the dosing line would be a problem. It's all very clean on each end with zero sign of urea deposit build up.
No, the fuel pump runs with engine running only.
It's either EGR cooler pump or auxiliary coolant pump
Aha ! That's interesting
Probably a red herring but in your original log it had the following:
It is showing the Urea concentration of 0% and therefore the quality to be invalid.
I think the concentartion should be around 35% ? - Is that correct @mmi ?
Where did you get the ADblue from, and is it now looking better since you have refilled the tanks etc?
| IDE10032 Reducing agent quality sensor: urea concentration 0.00 % |
| IDE10039 Reducing agent quality sensor: validity invalid |
It is showing the Urea concentration of 0% and therefore the quality to be invalid.
I think the concentartion should be around 35% ? - Is that correct @mmi ?
Where did you get the ADblue from, and is it now looking better since you have refilled the tanks etc?
Well, correct for this engine software I would say. This far for CXGB engine software 04L 906 056 KA only those values have been observed (blockmaps of 6 different engines in the Forum). However, some other engine softwares indeed report non-zero values.
E.g. other maps
here --> Won’t start. No fault codes
here --> ABS/Traction control lights still on
here --> More Adblue woes
etc.
Some earlier correspondence on this peculiarity
So I got the Adblue from the local Tesco petrol filling station. I can't remember the name of the exact brand but I have seen it about in lots of places so I'm assuming it is going to be OK. I do get the feeling that it should hopefully just sort itself out soon enough. I'm sure I should find out when I drive to Kelmarsh and back (240 mile round trip).
Pegsoid342
Member
I managed to make it back from France without any issues. After monsieur mechanic did his stuff it showed 6500 miles remaining, I’ve now driven nearly 800 miles and it still shows 6500. Is this the maximum it will read and maybe the tank is over full?
I had an engine management light appear about half way into the journey.
Question is now do I leave it to see what it does? Take it to VW to potentially solve (expensively) any underlying issue or delete the ad-blue system all together?
Will deleting the ad-blue affect the emission reading on the MOT or have any other knock on effect?
I don’t do many long distance trips so happy enough to see what it does but will be doing France again next year and can do without the stress of this problem again.
Any advice appreciated.
I had an engine management light appear about half way into the journey.
Question is now do I leave it to see what it does? Take it to VW to potentially solve (expensively) any underlying issue or delete the ad-blue system all together?
Will deleting the ad-blue affect the emission reading on the MOT or have any other knock on effect?
I don’t do many long distance trips so happy enough to see what it does but will be doing France again next year and can do without the stress of this problem again.
Any advice appreciated.
