Battery saver mode

[Nato123]

Hey all,
Purchased an 07 ve Calais around 3 weeks ago. Turned it on today to drive home from work and had a ‘battery saver mode on’ message appear on the dash and then a few minutes later had a check engine light appear on the dash and stay there.

Is it common for these 2 messages to appear together?
would I be right in thinking the alternator or battery is on its way out? Or do I need to get the car scanned to know for sure?

Thanks in advance for any help

 

[shane_3800]

I've never come across this issue in the 12 years in the trade but I would first start by load testing the battery.
I would assume the PCM lost input from the alt and it was either puting out 8v or 0v.

 

[Nato123]

I've never come across this issue in the 12 years in the trade but I would first start by load testing the battery.
I would assume the PCM lost input from the alt and it was either puting out 8v or 0v.

Hey mate, just checked to see if the alternator is charging and it is no worries. Battery is at 10.7 volts on a load test. Is that getting low or around normal? Thanks

 

[shane_3800]

Hey mate, just checked to see if the alternator is charging and it is no worries. Battery is at 10.7 volts on a load test. Is that getting low or around normal? Thanks

How did you load test it? If yoi used a carbon pile load tester it should have the CCA reading on the gauge and it should hold 80% of that. If you used an electronic one it should give you a equasised read out in % of battery CCA.
The higher the CCA the less voltage drop will occur. So 10.8v is not relevant but from memory at about 600cca 10.8v is fairly healthy on a carbon pile load tester.

 

[Nato123]

How did you load test it? If yoi used a carbon pile load tester it should have the CCA reading on the gauge and it should hold 80% of that. If you used an electronic one it should give you a equasised read out in % of battery CCA.
The higher the CCA the less voltage drop will occur. So 10.8v is not relevant but from memory at about 600cca 10.8v is fairly healthy on a carbon pile load tester.

just ran a voltmeter off the alternator, not the best way but just was trying to get a quick reading.
Disconnected the battery and drained the power and reconnected it. The check engine light is now gone and showing no signs of a problem now

 

[shane_3800]

just ran a voltmeter off the alternator, not the best way but just was trying to get a quick reading.
Disconnected the battery and drained the power and reconnected it. The check engine light is now gone and showing no signs of a problem now

It could be PCM or the alt then. But go to a battery shop and get a propper load test done to ruel out a dead battery cell.

 

[Nato123]

Thanks for the help mate, will get that checked out.

Should I be concerned with the car completely dying on me with the battery saver mode coming on? Have read that people have lost all power when that has shown

 

[shane_3800]

Thanks for the help mate, will get that checked out.

Should I be concerned with the car completely dying on me with the battery saver mode coming on? Have read that people have lost all power when that has shown

It is a possibility.
The PCM regulates the alternator when computer moduels get below a certain voltage the IC can get very low volts causing all sorts of issues. While the car is operating ideally you want 14.4v this keeps the IC's happy. Dead batteries can sometimes show 14.4v on a volt meter but there can be very short dips in the milliseconds to very low volts that again IC's hate.
I'm not 100% on the IC's used in automotive but they should be around 200mhz to 400mhz.

So a 1 millisecond drop could cause issues. Only a scope will pick that sort of thing up.
It's better to just put a good battery in no scopes needed.

 

[lout]

the charging system on the ve commodores is controlled by the pcm
charging voltage can be anywhere from 12.6v up to 14.9v
battery saver mode is a progressive drop in non critical operations eg rear demister, air con etc
it is designed to get the battery charged at the soonest
if you cannot account why the battery would be low, eg listening to the footy with engine off, multiple short trips then i would be concerned
if the alternator is on the way out you will be running off of the battery voltage until the voltage gets too low and you stop.
as mentioned best to have battery tested and take it from there
if you measured 10 volts with engine running i would be very concerned

 

[Nato123]

the charging system on the ve commodores is controlled by the pcm
charging voltage can be anywhere from 12.6v up to 14.9v
battery saver mode is a progressive drop in non critical operations eg rear demister, air con etc
it is designed to get the battery charged at the soonest
if you cannot account why the battery would be low, eg listening to the footy with engine off, multiple short trips then i would be concerned
if the alternator is on the way out you will be running off of the battery voltage until the voltage gets too low and you stop.
as mentioned best to have battery tested and take it from there
if you measured 10 volts with engine running i would be very concerned

Thanks for the info, i do listen to the radio for 10-25 minutes with the engine off before work. Unsure if that would be a long enough time to drain the battery

The 10 volt measurement was when the engine was turning over on start up, I will try and get the car to a battery shop tomorrow to have a test