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Service Battery Charging System...one thing after another
Tahoe & SuburbanThe power, space, and brutal towing ability make the Tahoe and its longer sibling, the Suburban, arguably the best full size SUV's on the market today.
Platform: GMT 400, 800, 900
Service Battery Charging System...one thing after another
Service Battery Charging System...one thing after another
EDIT: 2007 Tahoe LTZ; 5.3L; 4WD; Flex-fuel; ~262k miles
Ok, so I just recently resolved my oil leak...and not even two weeks later, I get the Service Battery Charging System message in the DIC!! AAARRRGHH!
So I got my little battery tester do-hickey out and it tells me that the charging system voltage is too low, it's putting out about 11.88V. Car is running fine right now, no other issues, drives just fine. The charging system gauge in the vehicle shows ~12V, which matches my battery tester.
I'm ready to just buy a GM OEM alternator on ebay for ~250.00 and call it a day. The dealership wants ~570.00 just for the part, LOL!
But my questions are, can I continue to drive the car until the new alternator arrives? And could there be any other cause other than the alternator for the Service Battery Charging System message?
Thanks! Charging voltage from my 07 Tahoe. Charging voltage from my 98 Acura Integra, I just wanted to make sure my battery tester was being helpful, lol!
Last edited by Typerod; Jan 12, 2019 at 12:39 PM.
Reason: added vehicle info
no for driving. you battery is supporting all the electrical needs to operate the car...without the charging to recharge the battery...it will eventually die on the road or no start.
most batteries have a reserve capacity rating....the amount of time it can put out a set voltage....that is what is keeping the truck going...when its discharged it will freeze and destroy the battery. charge up the battery now
no for driving. you battery is supporting all the electrical needs to operate the car...without the charging to recharge the battery...it will eventually die on the road or no start.
most batteries have a reserve capacity rating....the amount of time it can put out a set voltage....that is what is keeping the truck going...when its discharged it will freeze and destroy the battery. charge up the battery now
Thanks tech2! I will heed to your advice. Do you think this is most likely an alternator issue? Or can there be another issue that will cause the alternator to have such a low output?
My $.02 worth, have the alternator tested. If you are just reading battery voltage with the engine running, as Tech2 says probably the alternator. I believe the pcm controls the field voltage to the alternator instead of the "good ole" external voltage regulator, but again if it's not charging, have it tested, and be prepared to replace the alternator.
I didn't see what year or model you have, definitely charging system is not working. Make sure yours does not have a blown fuse or fusible link protecting it, that's a lot of bucks for a replacement alternator. Also make sure the connections are clean and tight.
Try hitting the alternator with a hammer.
The best would be a rubber hammer so it’s not metal in metal. And see if that causes a spike.
In my 1990 f150 I had an battery warning light and the alt was only putting out about 8v. I hit it with a hammer a few times and it came back to normal.
That was about bout a month ago. I should order a new alternator because it’s clearly going bad. But, I’m going to roll the dice. The truck isn’t used daily. Mostly to run to the hardware store.
if I had to guess I would say a bad alternator. there will be a dtc set so you could retrieve it and we could test stuff.
I will scan it with my OBD2 tool, thx! Pls see my update below as well...
Originally Posted by kevinkpk
My $.02 worth, have the alternator tested. If you are just reading battery voltage with the engine running, as Tech2 says probably the alternator. I believe the pcm controls the field voltage to the alternator instead of the "good ole" external voltage regulator, but again if it's not charging, have it tested, and be prepared to replace the alternator.
Thx!
Originally Posted by Cusser
I didn't see what year or model you have, definitely charging system is not working. Make sure yours does not have a blown fuse or fusible link protecting it, that's a lot of bucks for a replacement alternator. Also make sure the connections are clean and tight.
Sorry! 07 Tahoe LTZ 5.3L Flex fuel 4WD, ~262K miles on the motor, alternator is the original one. I will check the mega fuse, but if that was blown, I believe I wouldn't see any charging voltage on the battery. I should also mention I dual Odyssey AGM batteries, but that shouldn't have any affect on the diagnosis. I triple checked all battery and ground connections, so I'm good there.
Originally Posted by Collkid
Old trick.
Try hitting the alternator with a hammer.
The best would be a rubber hammer so it’s not metal in metal. And see if that causes a spike.
In my 1990 f150 I had an battery warning light and the alt was only putting out about 8v. I hit it with a hammer a few times and it came back to normal.
That was about bout a month ago. I should order a new alternator because it’s clearly going bad. But, I’m going to roll the dice. The truck isn’t used daily. Mostly to run to the hardware store.
Tthanks for the suggestion, but I think I will pass on banging on it, lol!
So just an update...I went ahead and checked the vehicle again today, battery light is out and the Service battery charging system message is gone, BUT I checked the alternator charging voltage and the tester now tells me it is HIGH, its charging anywhere from 14.8V to over 15.2V.
I couldn't get to the dealership with the best deal on the alternator on time, b/c its an hour away. I'm just gonna order it from amazon and hopefully the snow tomorrow won't affect its arrival on Monday, lol!
Could the charging voltage be high b/c the car's computer saw that the batteries needed charging and kicked up the charging voltage?
I'm currently charging the batteries I'll recheck the charging voltage again and will report back
the pcm has 10 charging modes but none should drop below 12.6volts. you could do voltage drops test of the insulated and grd circuits and check the field circuit control wire from the pcm to the alternator. the voltage drop tests will confirm you don't have a loose connection or high resistance in a wire.
the pcm has 10 charging modes but none should drop below 12.6volts. you could do voltage drops test of the insulated and grd circuits and check the field circuit control wire from the pcm to the alternator. the voltage drop tests will confirm you don't have a loose connection or high resistance in a wire.
Thanks tech2.
Does the pcm have a charging mode that will allow the alternator to output more than 15V?
The voltage drop testing you describe is a bit out if my wheelhouse, lol! If I had a step by step procedure, and pictures of the locations of the circuitry, I may give it a shot, lol.
Another update from last night, I moved the vehicle to charge the batteries, and it seems that the situation changes with the wind, the battery light is on again and service battery charging system message is on. Hopefully the part will arrive tomorrow, but the snow today in Northern VA may delay that. I will update once I get it installed.
Service Battery Charging System...one thing after another
