Hacking your car’s multifunction display

attiny_mfa_switcher

[Steve] has an older third generation VW Golf, and as those who have owned one surely know, the beloved VR6 engine is wonderful but finicky. He says that the VR6 is particularly picky when it comes to oil temperature, so his daily routine involves hitting the MFA switch five times upon starting his car to bring up the oil temp in the display. This obviously gets old after awhile, so he rigged up a small circuit to do the switching for him.

He pulled the gauge cluster from the dash and then located the pins that correspond to the MFA display switch. Using an ATtiny12, he put together a small circuit that toggles the switch for him automatically each time he starts the car. Since his solution uses so few parts, he was easily able to tuck his creation behind the gauge cluster before reinstalling it.

Now each time he gets in his car, he is quickly greeted with the engine’s oil temp without having to fuss with his display.