: Check Engine Light - can Onstar Diagnose?

02-25-10, 10:13 AM
Hey all,

I was slogging my through a snowstorm to Chicago last night and my check engine light came on. I'll have to drive home for 5 or 6 hours on Friday before I can have a dealer look at it.

I was wondering - does Onstar get direct diagnostics from the car so they could give me some idea of what the problem is?

02-25-10, 12:38 PM
sure just call them thru onstar---my bet is you got your oxygen sensor wet--that happeend to me a month ago--luckily a friend of mine has one of thise code reading machines that cost $200, he found the code,cleared it,and ive been fine.The way these codes work, you have to clear it, or even if it fixes itself by in this case drying out, the light will stay on

02-25-10, 03:35 PM
Yes, and if you really beg OnStar, they will tell you what the Diagnostic code is. I have done this with them before and at first they will tell you that the code is either nothing to worry about, or they will want to send a wrecker to you to carry your car to the dealer. Let them know you are out of town and just want the code reading.

02-25-10, 05:28 PM
I agree---on a trip with my EXT i got the check engine light and at first they tell you "where" in the car system the failure occured, but if you tell them you need the actual failure--they can tell you--mine turned out with the EXT to be a gas cap that was loose (my fault).Plus,if the dealer dignoses it for you,your talking $100!!With On Star you can tell the dealer what it is