Check out this thread: [T6_measured] Monitoring DPF regeneration, DPF condition, EGR operation
Thanks for that, just need the egr flow rate. Wonder if there is a sensor or if it calculates it some how.
There is no flow sensor for EGR. Only intake air flow (MAF), the rest is calculated or looked up from map tables using airflow, temperatures, pressures, injection quantities, valve positions etc.
Check EGR rear and front pipes for splits or leaks, very common. Here’s a search on forum regarding the pipes: Search results for query: egr pipe
Could be a clogged EGR or something else as well but pipes are easiest to rule out.
Could be a clogged EGR or something else as well but pipes are easiest to rule out.
Attached the EGR flow rate as ECU reports it - in Torque app format - T6 EU6 engines.
EDIT: IDE07377
This is the specified flow, right? Ie EGR valve position will be regulated based on this value plus ofc other parameters.
Not sure how exactly EGR insufficient flow is detected but I suppose it could involve at least manifold pressure (too low), exhaust temperature (too high) and O2 (too lean) sensors.
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Yes, correct - IDE07377. It's simply because the other two PIDs (IDE03383, IDE07086) have never returned anything but plain zero value.
A bit mystery also to me. I have recorded various PIDs trying to find some correlation with the insufficient flow. However, it's a bit challenging from "wildly" varying data what one gets when driving around.
I believe the ECU's built-in test would be a controlled (and thus a good) way to estimate the flow deterioration - based simply on actual mass air flow sensor.
[T6_measured] 01-Engine - Built-in test for EGR
So it seems - inevitable P0401. Well, visited a VW garage to be tested - the van had accumulated 30 events in ECU's memory since July 2021 (since 20 months now). Eventually managed turn on the emission light at event number 31 - thus had a priviledge to have EGR flow tested. The result -...
Good call on the MAF, could be simply based on that.
Looking at these three PIDs (idling) IDE07374 = IDE07386 + IDE07377. If the EGR did not provide the specified air mass due to restricted flow, MAF flow would shoot up and provide most of the cylinder mass - easy to detect that in software. Just hypothesis though.
Code:
IDE07374-MAS05852,Cylinder mass flow: act. value calculated-Mass flow,43.2, kg/h
IDE07386,Total HFM air mass flow: calculated,32.4, kg/h
IDE07377,EGR valve 1: B1: mass current - specified value,10.8, kg/hEdit: the measured air mass PIDs are higher than calculated total air mass. So hypothetically insufficient EGR flow could be triggered when these reach or get too close to IDE07374.
Code:
IDE04468,Air mass at air mass meter 1,36.0, kg/h
IDE00347,Air mass: actual value:,10.18, g/s, translates to 36.6 kg/h
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