Disable E30 MPG Gauge

[petercory]

I have replaced E30 MPG Gauge & Tach with M3 Tach & Oil Temp Gauge. What has to be done to disable original E30 MPG Gauge?

[82eye]

I have replaced E30 MPG Gauge & Tach with M3 Tach & Oil Temp Gauge. What has to be done to disable original E30 MPG Gauge?

you list a much newer car in your profile.

if you actually swapped a tach, it probably won't work proper going from a 4 to a 6. as far as the mpg gauge, it's garbage anyway and is more a novelty than anything.

edit: i think it takes the signal off the tach if that helps.

[mbonder]

You'd need to use the 6 cylinder coding plug from the s38 to make the tach signal correct when going from 4 to 6 cylinder cars. For the oil temp you just need to get the temp sensor that the m3 uses and install it with wiring.

[petercory]

I have the correct Coding Plug as well as the correct Oil Temp Sender; I just wanted to know what, if anything was required to disable/eliminate the MPG Gauge and if its elimination affects the Tach or anything else.

[richardodn]

The tach and mpg gauge are both driven from the SI board. Looking at the 88 M3 diagrams, it looks like the tach is still driven from the SI board and the old mpg gauge pins are simply "not used"

[petercory]

Do I have to remove the wires going to those pins in the connector plug?

[nick325xit 5spd]

Do I have to remove the wires going to those pins in the connector plug?

You don't have to do anything to an M3 cluster when you swap it in, other than install the correct coding plug for your engine and hook up the oil temp sensor. You do NOT need to do anything re: the econometer.

Edit: To be 100% clear, you don't have to do anything to the cluster OR to the car wiring. Oil temp is a totally separate plug.

[petercory]

Thanks for your detailed reply Nick - greatly appreciated