The range is terrible on my 2005 Trailblazer. Sometimes it will unlock from 30 feet away if I am behind the truck. Usually if I am coming from the from I end up standing right by the drivers door before the door will unlock. This is with a brand new battery. If I want all doors unlocked, often by the time I get it to respond a second time enough time has elapsed that the driver's door is all that will unlock again. Is there any adjustment or cleaning that can be done? Where is the sensor?

When you press a button on a transmitter, the transmitter sends a signal to the liftgate module. The liftgate module is a problem in this vehicle. It communicates with other modules through serial data. If you watch a scanner the module can't decide whether it has a code problem or not. The module has control over other things and has the tendency to confuse other communication modules, namely the body control module which controls the lock actuators.

The liftgate module is in the liftgate. Hard slamming of the liftgate will hurt this module.

It does need to be programmed when replaced.

No adjustment for this, u may just have a defective remote, does the radio work ok? the remote transmittws to the radio antenna.