480 Onboard computer reset

[M D E]

Hi, does anyone know how to re-calibrate the computer for the fuel economy instant, average and range mpg, also my fuel gauge is going down but the range on full tank reads 600 miles ! According to the computer my average MPG is 46 and instant reads around 60 mpg at 3000 rpm ....many thanks

[B20F]

You can only reset these readings by holding the reset button on the multi-selector switch. Did you try this? As far as I know you can't recalibrate the BC, most of the times these faults are caused by bad solder joints on the printplate of the BC or bad connections at the back of it.

[veegard]

I own a 460 without an info centre, but I believe plugging out your ECU and keeping it that way for about 3 hours should reset everything possible.

[B20F]

To reset the ECU you just have to disconnect the minus from the battery for about 10 minutes, that's all it takes. No need to disconnect the ECU itself.

[veegard]

Well yeah, or do that. Whatever keeps it from getting a closed circuit. I just happen to have all my panels off all the time, because something keeps breaking.

[M D E]

Thanks for your comments, Try re-soldering all the joints on the back on the circuit board and also the tracks inside the speedometer unit ... It takes some time but my computer never fails to display now ... I Just need to reset it !

[GLTease]

Hold the reset button turn key to II wait a bit, that will reset your info centre.

[veegard]

Lucky bastards with info centres.. mine's old school :(

[GLTease]

Lucky bastards with info centres.. mine's old school :(

Sometimes wish I could go old school, can be a pain in the arse when they go wrong

[veegard]

Well, mine is a pain in the ass anyway. Harh.

[Clan]

Therer is a calibration screw behind a small round blanking cover on the selector switch ,
It is for calibrating the bar gauge fuel level indicator , you fill the tank and adjust so that the top bar just comes on ... This may improve things ..

[Baffler]

Therer is a calibration screw behind a small round blanking cover on the selector switch ,
It is for calibrating the bar gauge fuel level indicator , you fill the tank and adjust so that the top bar just comes on ... This may improve things ..

After filling the tank make sure the car is on a level surface. You need to set the info centre switch to FUEL AVG, hold the reset button, turn ignition to position II, you will see a readout of the amount of litres on the gauge, then adjust the calibrating screw with a miniture flat driver so the litres show 59 (applies to mid 1990 models onwards)

Hope this helps...

[Clan]

excellent , a perfect description of what i was trying to say ! I Havent done this for over 15 years , it was part of the PDI ...