Why is my new GMC Yukon Voltmeter gauge acting this way?

[KenK]

I have a new 2011 Yukon with only 1300 miles. It has the 5.3 engine. The voltmeter gauge sometimes is at 14-15 volts and after awhile drops to less than 14, say 12-13. My ford always seems to be at 14.2 or 14 vots. The GMC has the tow package and HD alternator. Is this an artifact of that package? The oil prssure gauge runs a lot lower than normal also but there was another thread on this. I think this is normal.

Ken

 

[gnarpow]

In the NNBS trucks (2007-current) the volts do fluctuate as you mentioned. Its due to an on demand type charging system to increase efficiency.

---------- Post added at 04:05 PM ---------- Previous post was at 04:01 PM ----------

Here is some more information on it, evidently it is right out of the manual:

Battery Voltage Gauge Operation
The IPC displays the system voltage as received from the BCM over the GMLAN serial data circuit. If there is no communication with the BCM then the gauge will indicate minimum.

Utilities and light duty full size pickups are equipped with a new regulated voltage control (RVC) system. This system turns off the alternator when it is not required in order to improve fuel economy. The generator will turn back on when 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.

 

[KenK]

Thanks! These new GM cars are a little confusing.

 

[edgaranah1]

yeah dont worry its normal. I hadnt noticed til my dad drove it a couple of days after I bought it and told me. took it to the dealer and they explained it to me.


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