Anyway to rest an m20 obc?

[Kozworth]

Hey guys,

I am running into a pickle here. I am having bad mileage issues, my odo is broke, so I am now half questioning whethor or not how bad my mpg really are.

I was wondering if there was a way to reset or fix my obc. Basically, it says the average mph is ------, a bunch of buttons come up as ------. It came up that the temperature was 2 degrees c, which i am not sure if its correct (weather.com says its about 32 degrees F, so its close) or if its just luck that its almost right.

However, when I hit average mpg, it came with 39.5L 100? I dont understand.

Does it mean I am getting 39.5L of fuel for every 100 miles? That is not too user friendly if I have to do all that conversion! Thats about 10.5 Gallons, which means I am getting 10mpg (not that thats too far off from what I am guessing I am getting).

Eithor way, half the other OBC functions do not work. Please let me know if theres some way to reset it, it seems like a cool accessory!

Thanks

[jlevie]

It rather sounds like the OBC isn't getting a speed signal from the cluster. In which case the MPG reading may be invalid. Well that or the OBC isn't working.

[Kozworth]

I do not think it really worked even before my speedo kicked out..

But i forgot to mention that. I will press all the other buttons and let you guys know what it reads

[AndrewBird]

The L per 100km thing is how they do it in Europe and other places. The OBC is probably set to metric, not SAE.

[Chuck C]

Sounds like your OBC is in default euro mode. To change the mpg display to US English, press the AVG MPG button, then use a ballpoint pen to press the changeover contact in the lower right hand corner, and cycle through the options until you get US readings. My memory is a little fuzzy--been a long time since I did PDIs on these cars. Anybody have an owner's manual?

[FLG]

If i remember correctly Chuck is correct.

[fatsooo]

i do this on the regs, my battery likes to disconnect itself.
its just one click on that corner to set over to MPG...you can also use that button to set the time/date as well.

click the hr/date button
use the pen to push in the changeover contact on the bottom right corner of the OBC
use the respective buttons to change the time (for instance, 2:32 PM would be as many clicks to 1000 to make it say PM, no clicks to 100 since it starts at 2, 3 clicks to 10 to go to 30 and two clicks to 1 to make it say 2)
once you have set the desired time you push the changeover contact again. and youre finished
click the hr/date button again to do the same with the date.

make sure you convert the average mpg over before doing the date/time otherwise it will still be in euro mode and a tad bit more tricky

[smooth]

It rather sounds like the OBC isn't getting a speed signal from the cluster. In which case the MPG reading may be invalid. Well that or the OBC isn't working.

This is something I always wondered when my odometer was broken. Does the OBC collect it's data from the cluster or from the sensors (the diff, the DME, etc.)?

[jlevie]

The road speed signal goes from the sensor in the differential to the cluster and then (via a wire that plugs into the green connector) to the OBC and cruise control.