On Board Computer Reset?

[loganhopeless]

My On Board Computer has been weird since I bought it. It always says -30C, and some other screwey things but won't let me change it or anything. Is there a way to reset the whole computer? Thanks.

[XwalkerX]

sounds like you need a new ambient air temp sensor

[loganhopeless]

It's the temp but as well as the date/time, it just gives me dashes and I can't set anything.

[TimeMachinE30]

Try replacing bulb and air sensor.

[long tall eta]

take the point of a pen and push in the very small button on the lower right. then hit the set (lower right button) and the miles per gallon button (the second one down on the left both at the same time. this will reset to standard US.

[estoguy]

If it's reading -30, the temp sensor is gone.

What year is your E30?

When you do your oil changes, if your SI board is working, you can reset the indicator lights using a paperclip. Search the web... there are instructions on how to do that.

The computer diagnostics except for late models with OBD 1 are rudimentary at best.

[101]

is this a "6 button" or a "13 button" OBC?

I agree that the air temperature sensor is gone or disconnected if you're reading -30'.

Disconnecting the battery will reset the OBC. And then follow the procedure in the owner's manual exactly to set the time and date. It's pretty unforgiving if you miss a step.

[loganhopeless]

It's an 88'. And it has the 13 button OBC. I will try setting it to US, and then look at replacing the air temp sensor. I'm replacing the battery this week, so hopefully that does the trick too. Thanks!