E30 Zone

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

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.

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

So are there any wires that i could check anywere? Wouldnt mind having it workin

daveyboy20 wrote:So are there any wires that i could check anywere?

If the speedo works, then no. It gets another feed from the ECU, but there's unlikely to be anything wrong with that wire.