This 2005 Chevrolet Impala came in due to a battery drain condition. I checked and sure enough the was a 2.25 amp drain on the system at all times. In researching I found something interesting about the Tech 2 and monitoring sleep and wake modes. I hooked the Tech 2 up and went into the class 2 message monitor to view the module state (active or inactive). This can be done with the key off and of course active means awake and drawing current and inactive means asleep and not drawing current. The interesting thing is the the number value after the status of the module also indicates sleep (even number) or awake (odd number) and it is cumulative. In that a higher number indicates that the module has gone to sleep and woke back up many times. A value of 15 would mean that the module has gone through the awake/sleep cycle 7 times and is currently back awake. The instrument cluster had the highest value at 137 after about fifteen minutes. Other modules also had high numbers but the instrument cluster was the highest. I disconnected the cluster and reset the monitor and all other modules went to sleep in less than two minutes. A new cluster and this car was fixed. I know this will probably only help some one that has a good scan tool but if you determine that you have a 2.00 – 2.50 amp draw, it may be worthwhile to disconnect the instrument cluster to see if the drain goes away.
Thank you very much for this info. I believe my Impala is suffering from this issue as well. My research also indicated that the instrument panel cluster on these vehicles is probably defective and should be recalled. Lots of complaints at the NTSB website.