OBD MPGuino gauge

[Magister]

I had problem with the VSS pid because of a programming bug , it is correctly reported by my ECU. Maybe your car is not fully compliant? Without VSS we can not calculate fuel consumption except fuerl used by hours or per minute maybe.

[dcb]

If it does indeed not have vss, then it is inconvenient but still not a lost cause. Many times we have regular destinations (i.e. home>work), and since you are still tracking fuel used, you can still "beat your high" score to those destinations without any extra thought.

OF course cars have speedometers and odometers built in, so you can look at the gph and divide it into the mph in your head to get instant mpg, likewise note the change in odo and fuel used for a longer term sample.

Another option, if you are really convinced you don't have a speed pid, but your car has a speed sensor is to make a hybrid obduino that monitors the speed signal directly (advanced topic), or just go with a mpguino.

You don't have any "check engine light" or stored trouble codes do you?

[gyb]

Magister thanks for the reply. I'll try to use vss seperate signal. I need to get the parts first.

[dcb]

Hmm... you have one of those obd plugs with vss on pin 14, interesting...

[gyb]

Originally Posted by dcb

If it does indeed not have vss, then it is inconvenient but still not a lost cause. Many times we have regular destinations (i.e. home>work), and since you are still tracking fuel used, you can still "beat your high" score to those destinations without any extra thought.

OF course cars have speedometers and odometers built in, so you can look at the gph and divide it into the mph in your head to get instant mpg, likewise note the change in odo and fuel used for a longer term sample.

Another option, if you are really convinced you don't have a speed pid, but your car has a speed sensor is to make a hybrid obduino that monitors the speed signal directly (advanced topic), or just go with a mpguino.

You don't have any "check engine light" or stored trouble codes do you?

Thanks for the reply. I 'd like to go "hybrid obduino" way. . I don't have any trouble codes.

[gyb]

Originally Posted by dcb

Hmm... you have one of those obd plugs with vss on pin 14, interesting...

I checked schematic diagrams of Data Link Connector(OBD) from Hyundai Service website. Hyundai Service Website. I think all hyundai vehicles have VSS in one of the pins of OBD connector.

[gone22]

Hey guys, I have an OBDuino and it works flawlessly on my 2000 Honda Accord (I built the ISO circuit with the Freescale K line IC). On the other hand, it does not work with my friends 1997 Altima. Both cars are ISO 9141. I am running OBDuino32k v157. For my car I keep the standard #define ISO_9141, for him the only way it'll connect is to uncomment #define ISO_14230_slow and comment #define ISO_9141. It connects to the vehicle, but all the values it reads are 0's. It refuses to get any readings, no errors of anysort, just zero's for all the PID's. Has anyone experienced this at all?

[mattjreilly]

Hmmm, bigmoe88, this sounds like what I'm dealing with. My OBDuino works flawlessly with my wife's 2005 Honda Pilot but will not work with my OBD-II 95 Subaru Legacy. Same thing, it won't connect unless you compile for ISO_14230_slow and then all the values are 0. Froggy was helping me with some debugging but I've had some jobs come up and haven't been able to work on it. I'll see if I can dig it out and find some time.

[Froggy]

The code for both 14230 inits are not too critical. If the ECU supplies any response to the init sequences, it just accepts it as good as gold and goes forth. With Matt's car we got a reply that should have come from a 9141 init sequence, but when we replied to the ECU with what we should reply with (as if in the 9141 init), the ECU was stone silent... It did not work. Nothing we tried worked.

We got a reply during the init process, but we never got the init process finalized...

I will look again at the code to see what can be done to help.

[Demonhawk]

Well I decided to give this a shot. I ordered my arduino, lcd, and all the various parts. I'm using the iso interface. I've gotten everything wired up and I tested it today in my vehicle(99.5 VW Jetta). All I managed to get is the Init failed screen. I've tried for Iso 14230 slow/fast as well as 9141. I checked the plug in my car as well as searched the web to confirm that my car does indeed use the iso protocol. I have also checked all my wiring and everything seems to be correctly wired.

I'm a bit of an electronics noob and I would like to know where I should go from here. What steps should I take next, etc? Thanks.