Multiple Fault Codes

[lmoengnr]

Alternator is running from 14.9-15v while driving isn’t this a bit high?

It's trying to work out the characteristics of the new battery.

 

[MaxCommie689]

Alternator is running from 14.9-15v while driving isn’t this a bit high?

Not really. My car runs between 14.2 and 15.0 volts in normal driving. This is with a 5 year old OE battery.

 

[HDJ]

Doesn’t end there for me honestly thinking of selling this car now as much as I love the VF LS3 I can’t keep going back and fourth with issues.
so this morning whilst driving my car battery showed 12.3-12.4 on the display even measured it at idle using multimeter it showed 12.4. so I’m thinking my alternator is cooked as well. Soon as I turn headlights on volts slowly climb up to 14.4v however with lights off it goes back down to 12.3-12.4v during driving as well is this normal? Or is my alternator dying?

 

[dassaur]

Doesn’t end there for me honestly thinking of selling this car now as much as I love the VF LS3 I can’t keep going back and fourth with issues.
so this morning whilst driving my car battery showed 12.3-12.4 on the display even measured it at idle using multimeter it showed 12.4. so I’m thinking my alternator is cooked as well. Soon as I turn headlights on volts slowly climb up to 14.4v however with lights off it goes back down to 12.3-12.4v during driving as well is this normal? Or is my alternator dying?

absolutely normal, dont stress

 

[HDJ]

absolutely normal, dont stress

absolutely normal, dont stress

to say I’m stressed would be an understatement haha.

absolutely normal, dont stress

hope you’re right as just yesterday it was at 14.9-15v while driving and today it’s 12.3-12.4v

 

[Skylarking]

@HDJ, suffice to say, the way the BCM charges the battery isn’t like alternators of old and can leave one feeling that some gremlins are in charge

So it may be worth reading the whole BMC charging thread though I’ll drop you in the middle of it here …

The workshop manual may be a good read in itself…

 

[dassaur]

to say I’m stressed would be an understatement haha.

hope you’re right as just yesterday it was at 14.9-15v while driving and today it’s 12.3-12.4v

As Skylarking has indicated it is part of the normal charging system.
My advice is to navigate away from the voltage display and relax. I am speaking from experience, especially given the auto electrician advice and new battery.

 

[LS3SS-Ute]

@HDJ Any updates on this? I'm having a battery problem that sounds similar - fully charged battery will last a week or two before going flat and shows 12.3 to 12.4 on dash when normal driving. Cheers

 

[Skylarking]

@HDJ Any updates on this? I'm having a battery problem that sounds similar - fully charged battery will last a week or two before going flat and shows 12.3 to 12.4 on dash when normal driving. Cheers

TLDR; get your battery load tested and check for a high parasitic load when the car is parked.

Long story…

A fully charged battery will generally be sitting at an open circuit 12.8V or more. One that’s placed on a shelf in storage should last 6 month before a maintenance charge is needed.

Holden recommends an in vehicle battery be maintenance charged every 6 weeks if the vehicle isn’t being used.

Maintenance charge should be done at 12.3V (open circuit voltage) else battery sulfation will begin.

Charging lead acid batteries is a complex task because battery chemistry is complex.. Todays vehicle smart chargers aren’t the be all and end probably because of compromises in the charge logic because of patent issues. VE & VF use smart charger logic but unlike some makes doesn’t require programming when a new battery is added (the system learns that by itself if the drive habits are appropriate)…

If your battery is needing a maintenance charge after one week or two, presumably with the car being garaged during that time, I’d suggest that the battery either has some internal self discharge (due to sulfation) or the vehicle has some parasitic loss (where some rogue circuit is sucking the juice out of your battery).

If your car is being driven during the week or two it takes to drain the battery, then it can still be similar causes as above or it could be the alternator isn’t being commanded to charge at an appropriate rate (in which case check the battery current sensor and other parts of the charge logic as something may be amiss, check for any charge related DTC’s).

Below is some battery charge info

BU-403: Charging Lead Acid

BU meta description needed...

batteryuniversity.com

What’s missing from the equation is detail about the algorithm that the BCM uses which Holden doesn’t disclose within the workshop manual (which makes it harder to fault find that smart charger function).

PS: welcome to the forum.

 

[LS3SS-Ute]

Thanks mate, good post, funny enough I only bought the car a few weeks ago from dealer as well so hoping they can help fix it. Car is driven about 50kms a day so doesnt sit around much. I suspect this is the case "it could be the alternator isn’t being commanded to charge at an appropriate rate" but after reading this 7 page thread I was hoping HDJ could post the end resolution of what fixed his problem....even if it was selling the car