Factory Voltage Gauge Question.

[2010 Bumblebee]

My camaro's voltage gauge goes down to just over 12v like a tiny hair over. It will stay there for any amount of time like a half hour for example. Then it will move up to about 14v. I don't know if it is 14v because I have to guess.

Anyway I got it to do it and put a voltage meter on it because I don't know how accurate the factory gauge is. The hand helds meter said 12.9 volts. I've seen my factory gauge actually get a little closer to 12v but not under it. It fluctuates.

I was thinking maybe the computer controls the charging and that this may be normal. Like it is charging and resting, charging and resting.

Have any of you noticed this with your camaro? Take a look at yours before you reply.

[scott53]

I've noticed the same thing on my 1LT/RS. No idea why.

[2010 Bumblebee]

Originally Posted by scott53

I've noticed the same thing on my 1LT/RS. No idea why.

I'm thinking the computer controls the voltage regulator to either give the alternator a rest or to get slightly better gas milage (everything counts).

So, I'm thinking the computer lets the battery drain for a while then kicks in and charges it back up. Just a theory.

[TeH BawNeY]

Yeah it'll be at 14v on mine sometimes then as low as 12.2. Not really sure why at all either..

[The_Blur]

This is a great question. I'd love to have a GM engineer come in here and answer it for us.

[oachalon]

If i remember, in newer cars they are shutting off the alternators to try and gain gas mileage. They are letting the batteries drain more before kicking the alternator back on. My guess long term your battery wont last as long.

[clg_98ta]

Originally Posted by 2010 Bumblebee

I'm thinking the computer controls the voltage regulator to either give the alternator a rest or to get slightly better gas milage (everything counts).

So, I'm thinking the computer lets the battery drain for a while then kicks in and charges it back up. Just a theory.

I haven't heard of this before, but it would make sense. I'll try to start watching my gauge and see if it does the same thing.

[Sully]

yep, noticed it on mine too, i thought it maybe had to do with my radar detector, lights, stereo volume or my phone charger so i played around with all of them while parked and while driving and nothing seemed to make a difference so my first theories were dead wrong haha

[Optimus]

Interesting - i was gonna call my dealer tomorrow as my voltage gauge stays just above 9. Haven't seen it at 12 yet...

[HIGHOCTANE]

Originally Posted by Optimus

Interesting - i was gonna call my dealer tomorrow as my voltage gauge stays just above 9. Haven't seen it at 12 yet...

That definitely isn't right...my guess is the gauge is bad..if your voltage was that low you should have other symptons...

[firestone_ss]

you hit the nail on the head the pcm modulates voltages as needed,why would you need 14.6 volts all the time it makes sense,hell some makes are actually putting clutches on the alt.pulleys,look at new dodges its all about adding hp and lowering emissions

[lwlkr92]

From Owner's manual:
Battery Load
Management
The vehicle has Electric Power
Management (EPM) that estimates
the battery’s temperature and
state of charge. It then adjusts the
voltage for best performance
and extended life of the battery.
When the battery’s state of charge is
low, the voltage is raised slightly to
quickly bring the charge back up.
When the state of charge is high, the
voltage is lowered slightly to prevent
overcharging. If the vehicle has a
voltmeter gage or a voltage display
on the Driver Information Center
(DIC), you may see the voltage move
up or down. This is normal. If there is
a problem, an alert will be displayed.
The battery can be discharged at
idle if the electrical loads are
very high. This is true for all
vehicles. This is because the
generator (alternator) may not be
spinning fast enough at idle to
produce all the power that is needed
for very high electrical loads.A high electrical load occurs when
several of the following are on, such
as: headlamps, high beams, fog
lamps, rear window defogger,
climate control fan at high speed,
heated seats, engine cooling fans,
trailer loads, and loads plugged into
accessory power outlets.
EPM works to prevent excessive
discharge of the battery. It does
this by balancing the generator’s
output and the vehicle’s electrical
needs. It can increase engine
idle speed to generate more power,
whenever needed. It can temporarily
reduce the power demands of
some accessories.
Normally, these actions occur in
steps or levels, without being
noticeable. In rare cases at the
highest levels of corrective action,
this action may be noticeable to the
driver. If so, a Driver Information
Center (DIC) message might be
displayed, such as BATTERY
SAVER ACTIVE, BATTERY
VOLTAGE LOW, or LOW BATTERY.
If one of these messages display, it
is recommended that the driver
reduce the electrical loads as much
as possible. See Driver Information
Center (DIC) on page 4-27

[Stex]

+1, normal, same issue on the new GM trucks,,,see post # 3, similar system to that covered above...
http://www.gm-trucks.com/forums/inde...ator+fluxuates

[aldaran]

Originally Posted by lwlkr92

From Owner's manual:
Battery Load
Management
The vehicle has Electric Power
Management (EPM) that estimates
the battery’s temperature and
state of charge. It then adjusts the
voltage for best performance
and extended life of the battery.
When the battery’s state of charge is
low, the voltage is raised slightly to
quickly bring the charge back up.
When the state of charge is high, the
voltage is lowered slightly to prevent
overcharging. If the vehicle has a
voltmeter gage or a voltage display
on the Driver Information Center
(DIC), you may see the voltage move
up or down. This is normal. If there is
a problem, an alert will be displayed.
The battery can be discharged at
idle if the electrical loads are
very high. This is true for all
vehicles. This is because the
generator (alternator) may not be
spinning fast enough at idle to
produce all the power that is needed
for very high electrical loads.A high electrical load occurs when
several of the following are on, such
as: headlamps, high beams, fog
lamps, rear window defogger,
climate control fan at high speed,
heated seats, engine cooling fans,
trailer loads, and loads plugged into
accessory power outlets.
EPM works to prevent excessive
discharge of the battery. It does
this by balancing the generator’s
output and the vehicle’s electrical
needs. It can increase engine
idle speed to generate more power,
whenever needed. It can temporarily
reduce the power demands of
some accessories.
Normally, these actions occur in
steps or levels, without being
noticeable. In rare cases at the
highest levels of corrective action,
this action may be noticeable to the
driver. If so, a Driver Information
Center (DIC) message might be
displayed, such as BATTERY
SAVER ACTIVE, BATTERY
VOLTAGE LOW, or LOW BATTERY.
If one of these messages display, it
is recommended that the driver
reduce the electrical loads as much
as possible. See Driver Information
Center (DIC) on page 4-27

That is correct. My 2005 Silverado has the same system, but my 2000 Camaro does not.