OBD-II -> Peugeot 207 fuel consumption measure

Hello :)

At the moment I am gathering various type of data (e.g speed, rpm, temperature) from a vehicle (Peugeot 207 from 2009) using a OBD-II connection (EOBD). However, I cannot collect fuel consumption (in liters/100 km). I have checked previous forums but there most people use MAF sensor data to calculate fuel economy. However, my car does not seem to have a MAF sensor and does not provide MAP data as well; the OBD PIDs that the device can retrieve from the car are the following:

Your OBD Device claims to support PIDs:
PID: [column] human_name
00: [unknown] PIDs supported 00-20
01: [dtc_cnt] Monitor status since DTCs cleared
03: [fuelsys] Fuel system 1 and 2 status
04: [load_pct] Calculated LOAD Value
05: [temp] Engine Coolant Temperature
06: [shrtft13] Short Term Fuel Trim - Bank 1,3
07: [longft13] Long Term Fuel Trim - Bank 1,3
0C: [rpm] Engine RPM
0D: [vss] Vehicle Speed Sensor
0E: [sparkadv] Ignition Timing Advance for #1 Cylinder
0F: [iat] Intake Air Temperature
11: [throttlepos] Absolute Throttle Position
13: [o2sloc] Location of Oxygen Sensors
15: [o2s12] Bank 1 - Sensor 2/Bank 1 - Sensor 2 Oxygen Sensor Output Voltage / Short Term Fuel Trim
1C: [obdsup] OBD requirements to which vehicle is designed
20: [unknown] PIDs supported 21-40
21: [mil_dist] Distance Traveled While MIL is Activated
34: [lambdac11] Bank 1 - Sensor 1/Bank 1 - Sensor 1wide range O2S) Oxygen Sensors Equivalence Ratio (lambda) / Current
40: [unknown] PIDs supported 41-60
47: [tp_b] Absolute Throttle Position B

Any ideas how to calculate fuel consumption based on the previous PIDs?

I should also add that the car has an "On board Computer" that shows in real time in a display the following : fuel consumption, outside temperature, etc. Does anyone know how the car computer calculates the fuel consumption? and gets the outside air temperature? Why I cannot get this data from OBD?

Thank you!

Outside air temp is basically the same as intake air temp [iat].

About fuel efficiency, as we discussed in email earlier, I don't know but someone here may have a magically good answer.

Gary (-;

Decode pid 40 to see if pid 5E (Fuel consumption in l/h) is supported.
If it is supported you need scanner software that supports the new pids.
Then you can calculate l/100km from speed and consumption.

Hi,

Thank you for your replies!

@p2psmurf: All the lists I found about OBD PIDs were similar to the one in Wikipedia and there the PID 5E is not included. Do you know where I can get for free the list containing also the "new" PIDs? I would like to extract as much as possible data from the car.

@chunkyks: The outside temperature values I get from obdgpslogger (iat - around 40º) are a quite different from the ones I could see on the car display (around 17ºC). I first though you were displaying the values in ºF but then I made the conversion and it does not match...

The internet is a bit slow when it comes to updates. Since 2007 pids exist between 00 and 87 (hex). Free lists do not exist, you would have to buy the standard from the SAE.
This is a list of changes for 2007: http://engineers.ihs.com/document/ab...QIACAAAAAAAAAA

IAT (inlet air temperature) is almost always a lot hotter than the outside temperature, because the inlet manifold warms up. It's only equal to the outside temperature right before you start the engine when it's cold.

What's the value of pid 40? (Support for pids 41 through 60)

Everything that your car claims to support on mode 1 is listed there; if obdgpslogger doesn't recognise a PID, it'll say "unknown", but it'll still print it out.

[eg here's an old listing [before I included the short name] of my mini: mini-supportedPIDs. Note that "unknown" at the end.]

Gary (-;

can you tell me where the obd socket is loacated. I can't find it in my 207

@p2psmurf: The return value of PID 40 is just the following: "47: [tp_b] Absolute Throttle Position B". It seems that the car does not support PID 5E! It seems that I am at a dead end, no :(?

@chunkyks: Thank you for the information!

@Markdeurne: The OBD socket is located at the left side and bellow the steering wheel. The connector is not visible. You need to remove the panel where the button to regulate the height of the car lights is positioned. After you remove the panel you will find it at the top.

Hi,

I don't know if you are in a dead end. But I'm wondering whether that's no possible to estimate the air flow with the engine rpm, the engine load, the iat and the diameter of your intake manifold... Ok it will be approximate but like the formulae with MAP (VE is estimated too). I think there is a way to explore.

About PIDs meaning, our software (availble on your website) include a tool called "PID Decoder" which include the definition of PID until 0x87... To see them fill out the line with "FFFFFFFF"