GMC Terrain, Equinox, and SRX Forum banner

Service battery charging system and batt light on

119K views 21 replies 10 participants last post by  HP11 
#1 ·
I got a 2011 chevy equinox 2.4 has a new alternator and battery it's charging right but service battery charging system message come on and batt light on . Please help already tried what I could and still on . Thanks
 
#2 · (Edited by Moderator)
Chito_Lp said:
I got a 2011 chevy equinox 2.4 has a new alternator and battery it's charging right but service battery charging system message come on and batt light on . Please help already tried what I could and still on . Thanks
If you have a new battery and alternator and clean cables, check with a volt meter. You should read about 14.4 to 14.8 volts at idle.

As far as the battery light you might still have a previous trouble code in memory that was not cleared after the work you did. Have you tried to jump start another vehicle?
 
#4 · (Edited by Moderator)
Your alternator is charging but I think that is low. It depends on the state of charge of the battery.

Give the alternator a load, turn on the high beam headlights, A/C fan on high, etc. and rev up engine to approx. 1,500 RPM's. Check the voltage again.

Next I would go to the belt, two fuses, tensioner, and check for trouble codes.
 
#6 ·
No, I'm trying to see if your alternator will put out more with a load.
 
#8 · (Edited by Moderator)
the I4 should be the same.

but on the 3.6 (Traverse/ACadia with a voltmeter on the dash) and the 3.6 Equinox(with no voltmeter), the alternator is controlled by the computer. If the batt. is fully charged, and no load- the alternator output is lowered. If there is load (AC, defroster, seat heater) the voltage is ramped up.

Folks on the Traverse/Lambda forums always ask-- why is my voltage gauge showing around 13V sometimes---- other times its 15 V.

Well - its the computer doing its thing - based on batt charge and electrical load - that will result in what the alternator puts out.

Just an fyi- as to why he's asking for you to turn on loads.
 
#11 · (Edited by Moderator)
Chito_Lp said:
So I did put a load last night and it stays at a constant 13.5 volts I put the battery charger on the battery all night and this morning checked it again and still same situation . Any idea ?
I think 13.5 volts during charging, with a load, is too low.

From the 2014 GM Repair Manual:
There are six discrete programs (modes) that the BCM can run for the alt.

The most used is the Charge Mode:
"The system will set targeted alt. output voltage to a charging voltage between 13.9 to 15.5 volts depending on the battery state of charge and estimated battery temperature".

This charging voltage is set by the BCM:
Is the BCM setting the voltage too low or is the alt defective and cannot put out more than 13.5 volts? What is your battery voltage with the engine off and sitting overnight with no charger.

Did this problem just start or after a jump start, plugging in a device, or changing any electrical item? Did you check for trouble codes?

You may have to take your vehicle for a battery load test and alt/diode test just to rule out a bad one, even if they are new. The three major players here are the battery, alternator, and the BCM/ECM.
 
#12 · (Edited by Moderator)
My battery went bad so dealership swapped it out. I upgraded the power wire and grounds to 0 gauge due to audio system but light kept coming on and my alternator was throwing low voltage so I replaced alternator and put all original cables back on and ever since then service charging system has been on it's my daily driver and it hasn't left me stranded .
 
#14 ·
Chito,
The BCM and the ECM will send a signal to the DIC for the SERVICE BATTERY CHARGING SYSTEM message to be displayed. It is turned on when a charging system DTC is current. The message will turn OFF when the conditions for clearing the DTC have been met.
Have you checked for codes?
 
#16 · (Edited by Moderator)
Chito_Lp said:
I have a simple code scanner and nothing come out I guess I'll have to take it to dealership so they can hook up there computer ?
You have already changed out the battery and alternator/voltage regulator which are two likely causes of your problem. If you are confident that the two new components are working as they should, on to the next step

That leaves the BCM/ECM setting a DTC, and light on the dash with warning, for whatever reason. Probably time to get it professionally diagnosed.

Let us know what you come up with.
 
#17 · (Edited by Moderator)
I know that this may sound stupid, but could it be possible that the battery they put in was bad too? It happens. Battery can only get up to 13.5v no matter what the alternator tries to do? Just trying to look for the most simple answer.😊

I know that when I am charging a 6v battery at work, the charge will show it's max capacity of 6.55 v while charging but remove the charger, it goes back down to it's real capacity of let's say 6.08 v.

Wondering if that is how the alternator and battery works here too.
 
#19 ·
MY 2012 had the message service electrical system along with the battery light............put a meter on it while it was running and only like 11 volts............charged the battery while I installed the new alternator and started it up......no more message no light


my alternator had about 225 k on it when it wanted a vacation. I have put 30k on it since then with no issues.


I don't know if it will set a code for a non charging alternator other than the dashboard message.
 
#22 ·
I know this is an old thread. It kind of scared me because my granddaughters 2010 Terrain developed this same problem. I changed the alternator and the problem appears to be gone. I guess we'll see.
 
Top