I recently found out how do a cluster sweep on my Neon. I tried it on my 99 Dakota and it works on it to.

On a Dakota, you hold the trip button and then turn the key to ON and keep holding the trip button until the odometer says "Chec". It will then light up the Air Bag light, and run though the diodes on the LCD. Then it will test the needles.

I guess it would be a useful tool to see if your needles are working correctly. Sometimes a bad idle could just be a bad needle.

 

ill give this a go tomorrow i have a feeling my 4x4 light is dead.