MPG meter
Moderator: martauto
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daveyboy20
- E30 Zone Newbie

- Posts: 155
- Joined: Wed Oct 10, 2007 11:00 pm
- Location: The Wirral
Done a search but cant find anything. All the guages work great but the MPG one does nothing, it is permanently stuck to the left of the guage and doesnt budge at all even when the engines off. What can i look at to try and fix it? Cheers 
- Brianmoooore
- E30 Zone Team Member

- Posts: 49358
- Joined: Mon Jan 10, 2005 11:00 pm
The electronics for this are on the SI board, so you could try a different one of these, but I remember on one occasion when I came across this, I found a burnt out resistor on the speedo circuit board, and a transistor on the SI board that had blown in half.
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daveyboy20
- E30 Zone Newbie

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- Joined: Wed Oct 10, 2007 11:00 pm
- Location: The Wirral
The SI board? is this difficult to get to? i take it its behind the speedo? My mate siad the MPG guage works on some sort of vacuum is this right? If so could it be a hose? What else does the SI board govern? cheers 
nope it works on the injector pulse freqency and width and the speed sensor from the diff... its an accurate gauge not just a vacuum based guess.... sorry

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daveyboy20
- E30 Zone Newbie

- Posts: 155
- Joined: Wed Oct 10, 2007 11:00 pm
- Location: The Wirral
So are there any wires that i could check anywere? Wouldnt mind having it workin
- Brianmoooore
- E30 Zone Team Member

- Posts: 49358
- Joined: Mon Jan 10, 2005 11:00 pm
If the speedo works, then no. It gets another feed from the ECU, but there's unlikely to be anything wrong with that wire.daveyboy20 wrote:So are there any wires that i could check anywere?
