I'm having a problem with my 03 Yukon. The temp gauge doesn't work so I just ordered a new dash cluster. I get in truck today and start it up and the odometer goes to zero miles. The tach works but is reading really low. At idle, tach reads maybe 200 rpm's. Also, I get a left rear door open but it's closed. Do you thinks it's related to a defective cluster or do I have a faulty ECU or BCM?