[gmueller]

Is it possible to upgrade the onstar system for a 99 suburban (has analog phone). Onsta and Veizon and GM say no. Is this because of cost that GM does not want to pay?? Is it technically possible.

 

[73ChevelleSS]

No it is not possible.

 

[2002 Caddy]

It is not possible at a GM dealer... But a few enterprising soles have swapped over "upgradeable" OnStar modules from junk yards and taken the car into the dealer and had the patch applied... Their stories, and how they did it are out there.... Google.

 

[RB35SLT]

What about 2003 models? I have a 2003 GMC Sierra with OnStar, Can I upgrade it?

 

[73ChevelleSS]

What about 2003 models? I have a 2003 GMC Sierra with OnStar, Can I upgrade it?

It should be.If you PM your VIN I can check for sure.

 

[fp115]

It should be.If you PM your VIN I can check for sure.

He can also check himself if he wanted to...
https://www.myonstar.com/adt.os

 

[RB35SLT]

Look like I'm good to go. Thanks guys.