Electrical "Power Save"

[Okla-by God-homa]

My 07 Yukon XL has done a strange thing a few times. With everything running on high (A/C and Aux A/C) I'll come to a stop light and brake. While sitting there I will have the chimes come on several times and then the T/C (traction control) and ABS (braking system) will come on. When I start out from the light or stop sign everything goes off. The voltage gauge is reading somewhere around 12.5 but with that guage who knows.

I talked to the Service Writer at my dealership and he said "Oh yea, the '07's have a "Power Save" mode that will make it do that". Really????? :smilielol: That sounds like the biggest bunch of B.S. I've heard since an old girl friend said lots and lots of years ago......"it's only a cold sore".
Why in the hell would a vehicle have a power save mode for electrical? It's not like we can share the power. :mad2:

Personally I think I have a bad alternator, voltage regulator or battery.....anyone seen this before or have any ideas?

 

[73shark]

The "Power Save" feature basically just shuts down the alternator when it's not needed. Sounds like you have another problem.

 

[Getwired]

Find another dealer!

The person you talked to is full of crap. Try disconnecting the negative battery lead for a couple of hours to clear the trouble codes. If that doesn't do anything, take it in and make them fix it. NOT NORMAL.

 

[slvrbrchyukon]

my truck had to be towed 3 times after just sitting in my parking lot in a span of 3 months after i first got it. i don' t know what happend but the dealer had no clue either. i think your battery might be bad or it's old. they replaced my battery and it never happend again after that.

 

[gmcul8r]

This may or may not be related to a recall that went out on the new Tahoes/Yukons. I brought the letter I received to the dealership and was told they needed to reprogram the computer (didn't do it at the time b/c I had the Superchip in) because something was making the batteries drain abnormally. He said it was more for vehicles that sat for an extended period of time, like the ones on the lot. Could be related.

 

[Bugsy68]

I had a similar problem, though no chimes, just dropping voltmeter. Copied from another post:


Document ID# 2000522
2007 GMC Truck Yukon XL Denali


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Subject: Voltmeter Gage Fluctuation - keywords battery charge camper cluster electrical excessive fluctuation gage gauge generator intermittent ipc lamp light low operation trailer towing tow volt voltage wire #PIT3331D - (07/27/2007)



Models: 2005-2008 Cadillac Escalade, ESV, EXT

2005-2008 Chevrolet Avalanche, Silverado, Silverado Classic, Suburban, Tahoe

2005-2008 GMC Sierra, Sierra Classic, Yukon, Yukon XL, Yukon Denali, Yukon Denali XL

with Regulated Voltage Control (RVC)




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

Condition/Concern:
Some customers may comment that their volt gauge is fluctuating between 12 and 14 volts on their full size pickup / utility vehicle. Starting with the 2005 model year, light duty full size pickups and utilities, are equipped with a new Regulated Voltage Control (RVC) system. This system reduces the targeted output voltage to 12.6-13.1 volts when in "Fuel Economy Mode" to improve fuel economy. The alternator may exit "Fuel Economy Mode" if additional voltage is required. This will cause the voltmeter to fluctuate between 12 and 14 volts as opposed to non-regulated systems which usually maintain a more consistent reading of 14 volts. This fluctuation with the RVC system is normal system operation and NO repairs should be attempted. See picture below for the normal operating range of the voltage gauge. Review PIT4426 if having concerns with keeping a camper/trailer battery properly charged.





Recommendation/Instructions:
No repairs should be attempted and please reference the owners manual under Section 3 (Instrument Panel) "Voltmeter Gage" for more information.

Please follow this diagnostic or repair 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.
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© Copyright General Motors Corporation. All Rights Reserved.


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Document ID# 2000522
2007 GMC Truck Yukon XL Denali