Take a small wire and short pins 1 and 4 on the OBD-2 port, then turn the key to the "on" position. The ACD lights will flash to tell you what the fault code is. There will be a number of slow flashes, a small pause, then faster flashes. The slow flashes each count for 10 and the fast flashes count for 1 (for example, if you get 8 slow then 2 fast flashes, the error code is 82). If I remember correctly, pin 1 is the pin closest to the shifter.