'07 Trailblazer Issue(s)

[mbills2223]

I've had some electrical issues with this thing in the past. They are supposed to be fixed now...

Anywho....over the past month or so I've had to jump the stupid thing every dang time I went to start it. Battery is less than a year old. Take the battery to get tested at Auto Zone, it tests bad and gets replaced for free under warranty. Cool. Now the vehicle is starting right up every time, BUT after it starts it makes an unusual high pitched humming noise for about 30 seconds. Also, now when I go to turn off the ignition and remove the key, I can't. I can shut the ignition off but the key won't turn back all the way into the position it has to be in to remove it. This had happened a few times before I replaced the battery, but now it's happening every single time I shut the car off. I've looked online a bit, and I've seen a few things about a solenoid issue.

I'm no mechanic.

Has this happened to anyone before? Any thoughts on what the issue might be.

 

[infiremedic07]

High pitch whine. ..no idea! The key not releasing could to be a problem with the neutral safety switch in your shifter lever. It controls a solenoid to prevent key removal.

 

[chezuki]

Neutral safety switch is a common issue with a trailblazers.

When it wouldn't start, did the gauges go crazy when you tried?

 

[Mark-DuCo]

My wife's 2004 Envoy (same as Trailblazer) does the high pitched whine at startup, ours is the secondary air injection pump that is bad.

 

[churchmouse]

Are you getting all the way into park??????

 

[danimal]

My wife's 2004 Envoy (same as Trailblazer) does the high pitched whine at startup, ours is the secondary air injection pump that is bad.

You should hear the whine when the truck starts, you should be worried if you don't hear it!

The S-AIR pump is under the driver side of the vehicle, not too far up from the fuel filter (literally right under the drivers seat on the outside frame). Pump usually fails when the S-AIR valve (mounted to the engine) fails (sticks open) allowing condensate (exhaust) to backfill the pump... freezing temps and bam!... pump burns out from being submerged in ice. But you won't hear the pump if it's dead or fuse blew for it.

When changing the valve and pump on my wife's '04 TB, ended up needing to remove and clean the throttle body. Computer was having a hard time setting idle position after having battery disconnected for too long, throttle plate was too gunked up after 7 years, cleaned up and was good to go. Don't forget to grab a fresh gasket before you start.