OnStar Fuse

brufener · August 2, 2005

I have a 2001 Suburban 5.3 LT. It has the factory installed onstar, but it is not activated (i.e. I don't pay for the service). The green light next to the onstar buttons is on. The onstar speaker (in the headliner, right above the driver) buzzes sometimes, like I have a loose wire grounding or something. It will do it while turning, cruising at low speeds, stopping, with the engine on or off (but the key in the on position). As soon as the key is in the off position it stops. I'm 99% sure that the buzzing is coming from the onstar speaker.

I don't want to rip apart my headliner looking for the loose wire, so I was thinking I could just pull the onstar fuse. The problem is that I don't know which fuse is the onstar fuse. I have looked at both the interior and underhood fuses, and none are labeled onstar or anything similar. Any ideas on which fuse to pull? Any ideas on how to get the buzzing to stop besides pulling the fuse?

One other question - in my underhood fuses I am missing a large 30A fuse labeled "AIR". It is in the row of fuses that is closest to the engine block, and I think the 3rd or 4th fuse in from the front of the vehicle. I bought the vehicle used, so I'm not sure if it was ever there. Should I have a fuse there? What could this fuse go to? There is a fuse in the interior for the airbags, could there be two fuses for the airbags? Could it be some sort of air suspension option?

thanks,

Bryce

71GMC_3/4T · August 2, 2005

I don't think that's a speaker. I believe it's a fan for sensing the air temp for the auto climate control.

Taaaaaaahoe? · August 2, 2005

I don't think that's a speaker. I believe it's a fan for sensing the air temp for the auto climate control.

<{POST_SNAPBACK}>

Correct. Onstar comes through your radio. thats for your HVAC.

The AIR fuse may be for rear air option, or something you don't have by chance?

brufener · August 2, 2005

I thought it was a speaker because it makes the noise whether the HVAC is on or off. I've never heard the onstar because it isn't hooked up. That makes sense though, because when I first heard the noise it sounded like a fan hitting something.

I do have rear air in the suburban, and it works fine. If it was an airbag fuse and it was pulled, would an airbag light come on?

Anyone know how hard it is to get to this fan to fix the annoying buzzing noise? Any ideas?

Thanks

Taaaaaaahoe? · August 2, 2005

I do have rear air in the suburban, and it works fine. If it was an airbag fuse and it was pulled, would an airbag light come on?

Thanks

<{POST_SNAPBACK}>

Yes, and odds are other stuff would not work either. Maybe for the auto ride option?

Cant help on the noise, sorry...But can assure you its not an speaker.

Mike

GM-Tech · August 2, 2005

Buzz Noise From Headliner Above Driver - keywords ac air aspirator cover fan grille HVAC interior microphone sensor speaker temperature vent vibration #PIT3511 - (Mar 29, 2005)

2000-05 Cadillac Escalade

2002-05 Chevrolet Avalanche

2000-05 Chevrolet Silverado, Suburban, Tahoe

2000-05 GMC Sierra, Yukon, Yukon XL, Yukon Denali

The following diagnosis might be helpful if the vehicle exhibits the symptom(s) described in the PI.

Condition/Concern:

Dealer or customer may comment that they have a buzz or vibration noise emanating from the headliner in an area that looks like microphone or a speaker.

Recommendation/Instructions:

The plastic escutcheon grill, which is round and about the size of a half dollar and located just above the driver to the left, is the interior ambient temperature sensor. The sensor is used in conjunction with the automatic HVAC (C68). On occasions, this sensor has been known to make a buzz or rattle sound. The sensor uses a small fan to pull air over the sensor. This buzz noise may be intermittent.

Although it may not be possible to alleviate all of the buzz or noise from this sensor, Engineering has found that if the sensor is installed incorrectly that it may bind and cause the fan to make a buzz noise. Remove the sensor and while doing so check for any binding. Reinstall the sensor and re-test. If the noise is still present, the sensor itself may be noisy and require replacement.

Please follow this diagnosis process thoroughly and complete each step. If the condition exhibited is resolved without completing every step, the remaining steps do not need to be performed.

GM bulletins are intended for use by professional technicians, NOT a "do-it-yourselfer". They are written to inform these technicians of conditions that may occur on some vehicles, or to provide information that could assist in the proper service of a vehicle. Properly trained technicians have the equipment, tools, safety instructions, and know-how to do a job properly and safely. If a condition is described, DO NOT assume that the bulletin applies to your vehicle, or that your vehicle will have that condition. See your GM dealer for information on whether your vehicle may benefit from the information.

WE SUPPORT VOLUNTARY TECHNICIAN CERTIFICATION

willieboy · August 2, 2005

Sounds like the fan for the Stereo to me. Mine was doing that until I got it replaced.

brufener · August 2, 2005

Sounds like the tech bulletin is exactly what my problem is. I'll have to take a look at the sensor. Has anyone ever pulled the sensor before? Any tricks to taking it out? Do you just pry it out or do you twist it out. Anyone know how much a new sensor runs? I suppose I'll have a look at it tonight. Thanks again.

Bryce

Taaaaaaahoe? · August 2, 2005

got to love it here

bdeboer · August 2, 2005

Sounds like the tech bulletin is exactly what my problem is. I'll have to take a look at the sensor. Has anyone ever pulled the sensor before? Any tricks to taking it out? Do you just pry it out or do you twist it out. Anyone know how much a new sensor runs? I suppose I'll have a look at it tonight. Thanks again.

Bryce

<{POST_SNAPBACK}>

My 2002 Suburban was fixed for the sound in the technote by the dealer when I purchased it in February. The dealer fixed it as part of the purchase agreement, and I cannot remember what the cost would have been. The sound in mine would go away as the vehicle warmed up. They also said this was fairly common.