Onstar Box Location 2004 Yukon

stuffs2936 · October 6, 2011

When I purchased my 2004 Yukon (used in 2007) they upgraded the Onstar box to digital.

Recently I noticed the Onstar unlock (locked my keys in the truck) or even connecting to Onstar will not work with the Key out and engine stopped.

It works fine with engine running.

I suspect the new unit had a battery backup but my Alldata subscription does not show me where the box is.

I got a hint it might be back of the glove compartment but not sure.

Thank you in advance many times for your help.

govtech · October 6, 2011

the VCIM

"vehicle comunication interface module"

is located under your dash pad .

its easy but i cant explain it to you how to remove it ,let me see....

cluster trim,

open gove box

passenger grab bar (cant explain it )

remove side dash fuse/elect ctr covers

remove A pillar covers

remove all screws that retain cover,

pull rearward slightly,lift up,remove light sensor

remove fully,

VCIM is pass side

enjoy putting back ..be carefull ,use lots of lighting,

am i rite guys ?? lol

stuffs2936 · October 7, 2011

Don't waste your time, your truck does not have a BUB 9back up battery) and even if it did the BUB is not used for unlocking the doors. A BUB is only used when battery power is lost such as in a crash when the battery cable is severed or the battery is smashed to call for emergency help. Your VCIM is hot at all times the data line turns it on and off

Onstar could not unlock my doors remotely when the ignition was off, yet they could if the engine was running. I thought Maybe the VCIM was not wired hot? What do you mean by "data line". If I press the blue onstar button with the ignition off i get nothing but with the truck running it calls Onstar.

Any ideas?

Thank you in advance

stuffs2936 · October 6, 2011

the VCIM

"vehicle comunication interface module"

is located under your dash pad .

its easy but i cant explain it to you how to remove it ,let me see....

cluster trim,

open gove box

passenger grab bar (cant explain it )

remove side dash fuse/elect ctr covers

remove A pillar covers

remove all screws that retain cover,

pull rearward slightly,lift up,remove light sensor

remove fully,

VCIM is pass side

enjoy putting back ..be carefull ,use lots of lighting,

am i rite guys ?? lol

I appreciate the reply. Now I at least know the correct name for it. It may be over my courage level, but I will also look in the AllData now that I have the correct name.

I will dream tonight of getting wacked in the head as I set off the passenger side air bag! lol

Seriously I do thank you, many times! I do subscribe to Clint Eastwood's words of wisdom, " A man must know his limitations" It can be expensive and embarrassing when you show up at the dealer with left over parts.

govtech · October 6, 2011

passenger air bag is not removed/touched/felt/instructed to remove/etc ,,,...

but if you have limited experience ,then by all means ,please take it in ,,,, picking battles is a wise decision.

smart man

clint Eastwood ......awesome guy / movies

grand torino is the best !!!!! love that line about "gonna get ugly!! " love it !!

txab · October 6, 2011

This thread should show you how to remove the dash that Robert was trying to describe

stuffs2936 · October 6, 2011

passenger air bag is not removed/touched/felt/instructed to remove/etc ,,,...

but if you have limited experience ,then by all means ,please take it in ,,,, picking battles is a wise decision.

smart man

clint Eastwood ......awesome guy / movies

grand torino is the best !!!!! love that line about "gonna get ugly!! " love it !!

thanks smart man, the last dash I pulled was on a 69 Camaro back in the early 70's. It was that last dag gone screw I could not find until I destroyed the dash hoping it was just a stubborn clip. Those were the days.

Actually that is a great quote, "gonna get ugly" and very applicable to some of the madness involved in pulling these later models apart. I will be laughing about that for days! Thanks I needed some humor today!

stuffs2936 · October 6, 2011

This thread should show you how to remove the dash that Robert was trying to describe

Thanks a million txab! I appreciate all the help I can get!

txab · October 7, 2011

So, the unit worked correctly up until now? It suddenly quit operating with the key off?

stuffs2936 · October 7, 2011

So, the unit worked correctly up until now? It suddenly quit operating with the key off?

The truth is I never really tried to use it with the engine off, until recently. When the dealer upgraded it to digital when I bought the Truck in 07 I assumed it was wired correctly. From the surface it would appear it could being get power from the ignition circuit instead of battery power(always on). I have been going on the assumption it was wired correctly. I have used onstar but never in a engine off scenario. It does operate for about 2 minutes after the key is removed and then goes completely dead.

NitroCherokee · October 7, 2011

Don't waste your time, your truck does not have a BUB 9back up battery) and even if it did the BUB is not used for unlocking the doors. A BUB is only used when battery power is lost such as in a crash when the battery cable is severed or the battery is smashed to call for emergency help. Your VCIM is hot at all times the data line turns it on and off

Onstar could not unlock my doors remotely when the ignition was off, yet they could if the engine was running. I thought Maybe the VCIM was not wired hot? What do you mean by "data line". If I press the blue onstar button with the ignition off i get nothing but with the truck running it calls Onstar.

Any ideas?

Thank you in advance

The VCIM is hot all times, it goes into a low power mode for 48 hours on a GEN 6 VCIM. It will not work by a button press with the ignition off but should be able to receive a data call (unlock request from OnStar) which would "wake up" the VCIM and also the data line to which the VCIM sends a message to the BCM to unlock the doors. Most likely the VCIM is "bad" and not waking up for a data call

NitroCherokee · October 6, 2011

Don't waste your time, your truck does not have a BUB 9back up battery) and even if it did the BUB is not used for unlocking the doors. A BUB is only used when battery power is lost such as in a crash when the battery cable is severed or the battery is smashed to call for emergency help. Your VCIM is hot at all times the data line turns it on and off

govtech · October 6, 2011

This thread should show you how to remove the dash that Robert was trying to describe

trying ???? lol

i thought i did a good job !!!!

and i wont look at that thread ...lmao

stuffs2936 · October 8, 2011

Don't waste your time, your truck does not have a BUB 9back up battery) and even if it did the BUB is not used for unlocking the doors. A BUB is only used when battery power is lost such as in a crash when the battery cable is severed or the battery is smashed to call for emergency help. Your VCIM is hot at all times the data line turns it on and off

Onstar could not unlock my doors remotely when the ignition was off, yet they could if the engine was running. I thought Maybe the VCIM was not wired hot? What do you mean by "data line". If I press the blue onstar button with the ignition off i get nothing but with the truck running it calls Onstar.

Any ideas?

Thank you in advance

The VCIM is hot all times, it goes into a low power mode for 48 hours on a GEN 6 VCIM. It will not work by a button press with the ignition off but should be able to receive a data call (unlock request from OnStar) which would "wake up" the VCIM and also the data line to which the VCIM sends a message to the BCM to unlock the doors. Most likely the VCIM is "bad" and not waking up for a data call

stuffs2936 · October 8, 2011

Don't waste your time, your truck does not have a BUB 9back up battery) and even if it did the BUB is not used for unlocking the doors. A BUB is only used when battery power is lost such as in a crash when the battery cable is severed or the battery is smashed to call for emergency help. Your VCIM is hot at all times the data line turns it on and off

Onstar could not unlock my doors remotely when the ignition was off, yet they could if the engine was running. I thought Maybe the VCIM was not wired hot? What do you mean by "data line". If I press the blue onstar button with the ignition off i get nothing but with the truck running it calls Onstar.

Any ideas?

Thank you in advance

The VCIM is hot all times, it goes into a low power mode for 48 hours on a GEN 6 VCIM. It will not work by a button press with the ignition off but should be able to receive a data call (unlock request from OnStar) which would "wake up" the VCIM and also the data line to which the VCIM sends a message to the BCM to unlock the doors. Most likely the VCIM is "bad" and not waking up for a data call

Thanks for that input. I was under the "impression" that if someone was in an accident and the ignition was killed, they could push the blue onstar or redcross button to summon help regardless of status of the ignition switch. If the only thing I am losing is the ability to unlock my truck if I lock the keys in it, then I really don't need a new VCIM, I just need a half a brain. I felt like an idiot,,,, In this case my elbow must have hit the power lock button when I reached in the truck to get my glasses and that started all this mess. I think all of us just like stuff to work the way it should. It is like pulling teeth to get any information from Onstar.