Check for a blown fuse.
Into Park or out of Park?
The gear shift on a 2003 Trailblazer may be stuck in park due to a malfunctioning brake light switch, which prevents the shift interlock system from releasing. Additionally, issues with the transmission range sensor or a faulty shift cable could contribute to this problem. A blown fuse related to the shift interlock system might also be the cause. Lastly, if the vehicle's battery is weak or dead, it can affect the electronic components involved in shifting gears.
It keeps you from shifting out of park without first putting on the brake.
brake switch gone bad car will not shift out of park if brake goes bad
you have to put your foot on the break pedal, to shift out of park its a safety feature
Check to see if the stop lights are working. Shift interlock and stop lights are on the same circuit Try turning key to 1st (unlock) position then shift to Neutral to start vehicle and then shift to Drive
My button gets to where it won't push in so I can get the shifter out of park. I have to wiggle and keep trying and it will work. Not sure what part is messed up.
transmission shift bolt loose try pushing gear shifter all the way back to park
Do you have engine sludge? What all do you do with the car?
Short to ground on the shift interlock system?
I hear there was a problem with the parking switch. The parking switch (what I call it) is the mechanism that is connected to the brake which would need to be depressed before you could shift out of park. It is a safety feature. So basicaly when you would push in the brake pedal the switch would not activate and therefore you could not shift out of park. FYI there is a recall on the parking switch.
It could be a bad brake light switch. You have to step on the brake to shift it out of park.