BenzWorld Junior Member
Date registered: Nov 2017
Vehicle: 2009 GL320
Location: Austin, TX
Mentioned: 0 Post(s)
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Adblue metering too low, location of Adblue pump
I've been getting the CEL with a code that the Adblue metered quantity is too low. I've checked the real-time values and I can see that the metering enable signal has been issued, the metering amount goes up as I watch it and I can see the metering valve occasionally register a value above zero so it looks like the valve is functioning.
The unusual thing I see is that the Pressure in the Adblue delivery pump never goes about 13% (relative whatever that means).
The other thing that occurs to me is that it could be the downstream Nox sensor although I'm not getting any plausibility errors on it.
Does anyone know:
1) What is the normal delivery pump pressure?
2) Where is the AdBlue pump located?
3) How is the metering rate calculated?