Bought my wife an 03 TB LTZ about 3 mos. ago. She really loves it. So far I have had to replace the starter, alternator, cam position sensor and solenoid among other things. Nothing major, has been kind of fun getting to know it. The other day I noticed that her back up lights weren't working. Checked the fuses, one under back seat and the other under the hood. Looked good so I replaced the bulbs to be sure they were good. No luck. Tonight I unlocked it with the FOB, the exterior lighting came on and the back up lights came on with it. Put it in reverse to check them and they did not come on. Any ideas. Is there a sensor in the shifter or tranny that might be bad. Looking for ideas on where the problem might be. Not a malor issue but rather annoying. Bothers my wife more than me.