You know that little dot thingie near your 160mph readout? Well, we all know it's not a LED telling you you're hitting the top speed limiter yet we're told it's a phototransisiter. Here's how to see if it works:
This test is recommended to be done in a dark area or inside your garage. Turn to KL-15, which is ignition switch postion #2 and put on the parking lights. Get out your mini-flashlight in your glovebox. Then press any button on your OBC or multi-function clock. Set dimmer switch to low and aim the light to the phototransistor and watch the display matrix glow brighter!