Tsb info for a 1998 motronic 4.4 elevation flash

paul c · Post by **paul c** » 30 Jan 2018, 19:45

I've done a few searches and have come up empty. I'm looking for info on that tsb for the 1998 turbo cars on reflashing the ECM. A local dealer still has a functioning compaq laptop to do that flash. I just want to see if anyone has a copy or link to that tsb so I can check if my car falls with in the VIN range. Thanks

Post by **erikv11** » 30 Jan 2018, 22:21

Flashing the ECU is very easy these days, you can do it yourself with investment of a little time and common, cheap hardware. However I've never heard of an "elevation flash." Curious to see if anyone else has.

Post by **abscate** » 31 Jan 2018, 06:49

Flash for altitude? Don’t most every Systems monitor mass flow and pressure directly?

Post by **RickHaleParker** » 31 Jan 2018, 08:16

Flash for altitude? Don’t most every Systems monitor mass flow and pressure directly?

There is a altitude sensor, the ECM uses it to adjust boost and fuel mixture for air density.
On your '99 V70 it is located on the same mounding bracket as the outside temperature sensor.

The altitude sensor on my '98 C70 get wanky ~ 0°F makes it hard to start the engine.

Post by **erikv11** » 31 Jan 2018, 08:17

Yes, Motronic 4.4 monitors both.

Post by **abscate** » 31 Jan 2018, 10:24

Im noddling on this a bit. If the MAF really measures mass of air then the pressure should not really matter. Of course, it doesn't actually weigh the air, I believe ours are hotwire type sensors that measure cooling or heat transfer . That property would be a function of the density of the air flow, but it might intrinsically correct for pressure change..

Hmmm

Post by **RickHaleParker** » 31 Jan 2018, 11:23

If the MAF really measures mass of air then the pressure should not really matter.

Try solving this problem then maybe your get it.

The MAF is 12.5 grams per second. How much oxygen is there in one liter of air?

Post by **misha** » 31 Jan 2018, 11:34

Air or oxygen is not measuring in liters....it measures in grams or kilograms.
Am i missing something here?

Post by **RickHaleParker** » 31 Jan 2018, 11:41

Am i missing something here?

Air and Oxygen can be measured by Weight, Volume, Mass or Moles. Engine displacement is measured by volume.