2009 Sierra 2500HD Auto lock

[Jason Norris]

My doors won’t automatically lock when shifted out of park.  They will unlock when shifted into park though.  I have a base model and there is no programming feature available.  I looked at wiring diagrams but can’t see where the bcm gets its signal to lock from the gear selector or p/n switch.  Does anyone have any ideas on how to diagnose?

[richard wysong]

Even the base model is programmable I believe but do not recall the procedure. Have you looked in the owners manual?

[davester]

It probably gets that signal digitally, rather than a separate wire just for that signal.

[Jason Norris]

I did look and it only talks about accessing it through the DIC which I don’t have.  I saw a video on how to do it on earlier models by holding the high beam indicator back and cycling the key twice but it doesn’t work. 

[MORSNO]

If you can hear it unlock (if that is what is actually happening), it must have a lock feature accessed thru the driver's information center.  Even the base model has a way to access basic features by the odometer stem.

[Jason Norris]

If it does, I can’t figure it out.  The only option I can access is the language. 

[davester]

You have read through the owners manual?

[davester]

Add the DIC buttons. For my '12, it was just plugging in the DIC buttons , and light switch plug I think, and it just works.

[Jason Norris]

Yes I have.  It says to use the did buttons.  If I added them, where would they plug into?

[davester]

google "2009 silverado adding dic buttons"

[Jason Norris]

Hmmm.  So your saying the connector is there for the dic even if the truck didn’t come with it?

[davester]

Yes.

[Jason Norris]

Very interesting.  I’m going to look now.  

[Jason Norris]

You were right!  The connector is there.  I’m going to get a button set and see if it works.  Hopefully the cluster is programmed for it.  I saw a video where the guy just ran wires from the connector and tapped it to ground to toggle through the fuel mileage and vehicle settings and one of the options was doors lock in gear.  But it was on a 2004.  Not sure if the 2009 works the same way or if it uses resistors.  I’m not savvy with wiring diagram symbols 

[Jason Norris]

Wow fantastic thank you!  Buttons will be here tomorrow