Tag Archives: Logging

Log Graphs 1


Car: 2009 Impreza 2.0 Turbo Diesel, 110 kW / 148 hp / 150 PS, European domestic market, Euro 4 spec.

Important: Newer Boxer Diesel generations (Euro 5/6) may show different behaviour!

ECU firmware: patched ROM for unlimited logging, otherwise stock.
Protocol: SSM2 via CAN
More than 120 items had been logged, plenty of RAM variables (*) plus standard SSM2 items at roughly 170 ms interval.


I prepared two graph images plotting some interesting parameters, click picture for full resolution:

Image 1/2


Image 2/2


Additional details

… at specific time positions:

#1: State before active regeneration

Time @ ~ 33 ½ min
Cruise Control: active
Vehicle Speed*: 110 km/h
Engine Speed: 2300 rpm
Gear: 5
Coolant Temperature: 93 °C
Injections: 2 (pre + main)
Soot Accumulation Ratio: 64 %
DPF Pressure Difference: ~ 5 kPa
Exhaust Gas Temperature (EGT) Catalyst Inlet: 345 °C
EGT DPF Inlet: 370 °C
Intake Air Amount: 430 mg/cyl
Mass Air Flow: 33.8 g/s
Manifold Absolute Pressure (MAP)*: 126 kPa
Inlet Air Temperature: 25 °C
Manifold Air Temperature: 48 °C
Fuel Temperature: 58 °C
Throttle Opening Angle: 79 deg
EGR Valve Opening Angle: 38 deg
Final Oil Dilution Rate*: -1.9 mg/s (evaporation)
Oil Dilution Amount: 282.0 g (4.6 %)

#2: Soot 65%, preparing for DPF regeneration

@ 33 ¾ min
Soot Accumulation Ratio* reaches 65%, this triggers active regeneration preparations. Note: I am referring to the actual RAM value, diagnostic parameter may indicate 65% earlier due to rounding.
Apparently ECU now does 3 injections (pre + main + after) when power demand is high enough, no post injections yet

#3: Active Regen ON

@ 34:04; = 20 seconds after #2, DPF Regeneration Switch turns ON
EGR valve closes instantly, 0 deg
Manifold Air Temperature dropping
Boost Control opens VGT immediately, from 52 to 25%
Manifold Absolute Pressure* dropping
pilot-injection kicks in, 2 injections (pilot C + main)
post-injections begin to fade in but not active yet

#4: Post-Injections

@ 33 seconds after #2, post-injections A + B become operational (injection amount > 0)
oil dilution rising
EGTs climbing
Manifold Absolute Pressure*: 75 kPa (~ 25 below ambient), varying, stays below ambient most of the time during regen at low power demand
EGT Catalyst Inlet: 340 °C
EGT DPF Inlet: 320 °C
injections: 4 (pilot C + main + post A + post B)

#5: Coasting Fuel Cut-Off During Regen

Example @ 35:12
EGR valve opens instantaneously, 70 deg; EGR behaves rather digitally during regen – either fully closed (0 deg, for max EGT) or max opened (70 deg, less fresh air)
Throttle Opening Angle: rising up to 31 deg
injections: 0
Fuel Consumption*: 0 mm³/s
oil dilution going down slowly due to estimated evaporation
EGT Catalyst Inlet: decreases fast, EGT at DPF inlet (> 600 °C) follows with a delay
Engine Speed: gear change from 5th to 6th to reduce engine braking effect

#6: Idling with Active Regen ON

@ 45:30
Engine Speed: 800 rpm
Post A Injection Amount*: 0
Post B Injection Amount*: ~ 8 mm³/st
Apparently while idling the ECU prefers the 2nd post-injection (“B”), otherwise during driving it’s rather mixed
Final Oil Dilution Rate: ~ 20 mg/s (medium)
Boost Control: 25 % (VGT fully open)
Manifold Absolute Pressure*: 74 kPa
Throttle Opening Angle: 5.5 deg
EGR Valve Opening Angle: 0 deg
Intake Air Amount: 370 mg/cyl
Mass Air Flow: 9.8 g/s

#7: DPF Regeneration OFF

@ 46:15, decision is based on elapsed time from #2, achieved soot level does not matter (!)
DPF Regeneration SW had been ON for 12.2 minutes
all post-injections off
Oil Dilution Amount*: 299.6 g (4.9 %) = + 0.3 % during regeneration
EGR back to normal operation
Boost Control: 65 % instantly (max speed, spooling up turbo)
MAP rising
EGT Catalyst Inlet: 270 °C
EGT DPF Inlet: 490 °C

Updated Extended OBD-II definitions

Added 7 PIDs (0x10A1, 0x10A3..0x10A7, 0x1137), some are petrol-only, some diesel-only, some mixed.
See Extended OBD-II definitions page.
Downloads (spreadsheet, CSV) as well as ParsePID project are up to date.
Note that some PIDs have not been tested on actual cars yet – feedback is appreciated!

New pages: Software

Added new category “Software”. See sub-page Logging for software comparison.

Still incomplete and under construction. As always, do not hesitate to report feedback!


Just published my new little C# project:

ParsePID is a console application to analyse Extended/Enhanced OBD-II mode 22 capabilities, specifically for Subaru diesel and petrol control units supporting this protocol.

Go to http://github.com/SubaruDieselCrew/ParsePID/

  • README document includes demo output, currently for a diesel and petrol model.
  • The project uses published definitions from page Extended OBD-II, saved as CSV (delimiter: tab) format.
  • There is no need to compile the code for yourself if you haven’t got own data.

As always, do not hesitate to provide feedback…

Definitions Download for Extended OBD-II

Uploaded first draft of definitions file for diagnostics protocol Extended/Enhanced OBD-II. Should be easy to work with, can export to CSV etc. Everyone is welcome to use the data as long as it is mentioned where it came from.
Also added a few more PIDs in the meantime.
Go to page: Extended OBD-II

Protocols page Extended OBD-II

Added 3 more DPF related PIDs on page Extended OBD-II:

114A Pressure Difference between DPF Inlet and Outlet
1155 Estimated Distance to Oil Change
1156 Running Distance since last DPF Regeneration

Will add some more over time…
Apparently newer petrol models now also use this protocol (exclusively apart OBD-II, no SSM2 anymore ?). Might add petrol specific PIDs in the future.
Also, apps like Torque have been confirmed working with this.
Anyone able to provide any data, testing new or known PIDs, screenshots of software including SSM etc. or spot any issues, please get in touch!

Updated protocols page Extended OBD-II

Updated protocols page Extended OBD-II:

  • corrected “Exhaust Gas Temperature (EGT) at DPF Inlet”
  • added “DPF Regeneration Count”

Euro 5/6 model owners please test and report results, thanks!

Would also be interesting to know (logging) software capable of using this protocol. Tactrix Openport 2.0 standalone logging, Torque perhaps???