What is the Charging voltage for the 1.4?

[mvautodunn]

I've been having weird issues that I haven't been able to pin down. Sitting at a light at night I have a very noticeable what I would call a flicker where I see the headlights dim very noticeable then go bright. When I start the car the interior light takes 3-5 seconds before it goes full brightness.

I have been seeing on my ODBII reader live data its been charging at 14.8-15.2V all the time.

I took it in to the local parts store which had a digital tester and it said the battery and charging was fine but even he said it seemed a bit high.

I have been having issues for some time at even getting 29mpg. Doesn't matter how I drive it.

I got a odbII bluetooth adapter coming so I can use torque to get more daily driving readings.

Just curious if anyone has had this issue.

 

[kevjam79]

The alternator is undersized on the 1.4 to save on peristaltic drag, which improves power output and MPGs.

What is year, tranny and miles?


14 Sonic LT 1.8A MBM

 

[Chevrolet Customer Care]

I've been having weird issues that I haven't been able to pin down. Sitting at a light at night I have a very noticeable what I would call a flicker where I see the headlights dim very noticeable then go bright. When I start the car the interior light takes 3-5 seconds before it goes full brightness.

I have been seeing on my ODBII reader live data its been charging at 14.8-15.2V all the time.

I took it in to the local parts store which had a digital tester and it said the battery and charging was fine but even he said it seemed a bit high.

I have been having issues for some time at even getting 29mpg. Doesn't matter how I drive it.

I got a odbII bluetooth adapter coming so I can use torque to get more daily driving readings.

Just curious if anyone has had this issue.

Have you made your servicing dealership aware of this, mvautodunn? If you’re interested in working with them, we’d be glad to get that process started. Just send your VIN, mileage, contact information, and preferred dealership in a direct message.

Let us know!

Jasmine
Chevrolet Customer Care

 

[laborsmith]

I did not have those specific problems, but after doing a battery rundown test it appeared to me the alternator was the source. There being no high output alternator available, I did the Big Three upgrade, figuring I would need to do it anyways when a HO Alternator could be found. The upgrade did the trick and a year and two months later no problems.

The alternator is rated at 100 amps, but the cable to the battery carries 80 amps. Testing the alternator determined it could put out 110 amps, so you can see how the Big Three would be effective.

Yes, I have a bunch of aftermarket items that draw power.

Laborsmith

 

[Papasonic]

I have noticed variations in charging voltage after installing a digital monitor that function whenever the vehicle is operating. Always in the past, alternator output voltage was considered normal when around 13.2 to 14.6 volts; not an exact range, but thereabout. The older generation vehicles originally used mechanical regulators externally mounted from the alternator or generator. Later solid state regulators were located inside of the alternator. These days, the alternator doesn't contain a separate voltage regulating device, but uses a control module/computer to regulate output voltage. I've witnessed my particular Sonic voltage to be all over the place. One evening while driving, I looked at the monitor, and was alarmed that the voltage was 12.2 volts while at highway speed; turning accessories on or off didn't change the output. I thought at first that the alternator had failed, but it held the voltage no matter what load I put to it. I momentarily turned off the engine, then restarted; the voltage then read around 14.3 volts. Most recently, during cold ambient conditions, I have noticed the voltage stay around 15.2 volts, sometimes for two or three days at a time; then the next drive may show a more normal output of 14.3 volts.
A friend that has a 2012 Yukon Denali said that he too noticed wild variations in his alternator voltage output. He said that some research he had done on the topic led him to discover that GM had an unacceptable amount of premature Delco battery warranty claims and failures. His research showed that the batteries were deteriorating because of the way they were being charged by the vehicle. He went on to say that the voltage variations are built into the control module firmware to rejuvenate and attempt to prolong battery life.

Back to the topic: The Sonic's alternator output voltage is wildly variable, probably part of the reason why there is no amp or volt gauge included in our instrumentation. I've seen occasions where charging voltage is just above static battery voltage, all the way to 15.2 volts.

 

[laborsmith]

That was my experience using the UG. My memory is not perfect and I now recall the flickering etc. described above before doing the Big Three. The biggest problem I had was I would turn the engine off and have no electrical power, even after idling for a while before turning the key to off, which is why I started looking for a high output alternator.

Laborsmith

 

[carsNskis]

That was my experience using the UG. My memory is not perfect and I now recall the flickering etc. described above before doing the Big Three. The biggest problem I had was I would turn the engine off and have no electrical power, even after idling for a while before turning the key to off, which is why I started looking for a high output alternator.

Laborsmith

"Big three" referring to the power cable and engine + chassis ground?

.....drive it like you still owe the bank money

 

[laborsmith]

Yes

Laborsmith

 

[mvautodunn]

Its a 2012 Hatchback LTZ with the 1.4L with the 6 speed. About 46K miles. Completely stock.

As far as speaking to the dealership I told them about it twice about the fuel economy while it was still under 36K warranty but could find no issues with it. They could only recommend me to use "Select Brand Fuel" which I had but didn't help the mileage. Its also not throwing any codes.

I have been noticing very strong fuel odor in the oil recently making me suspicious I may have a compression or turbo issue. Both I will need to check that out more before taking it to the dealership.

I have been also having a periodic high idle where it pulls the idle to 1000-1100rpm but its something I haven't determined what causes it but if I stop and restart the car it quits. When it does it is completely random and inconsistent when and where it does it.

I've added an extra ground strap from the battery to the body and that body point to the engine. Which hasn't done anything ether way. If I can get some time on a decent day I need to do some probing with a multi-meter to see if something shows up and what the resistance is between wires.

I thought maybe the flickering and high charge voltage might be a weak battery but it load tested fine.

If anyone has anything that might point me in the right direction I would appreciate it.

 

[Fry]

When I experienced high voltage readings, flickering lights (sometimes while driving), and my radio resetting, a dealer told me that I should stop using heated seats and buy a battery maintainer to hook onto my car every night.

Naturally, I never went back to them and instead went to another dealer. Within about an hour, they found a loose ground connection somewhere under the battery was causing the battery not to charge very well. Cold weather made the problem worse. The high voltage was from the alternator trying to keep the battery charged. When the voltage would peak on my UG, that's when the radio and lights would flicker.

I'm not sure it fits exactly what's happening to you, but it might give some perspective.

 

[mvautodunn]

Thank you Fry, I am going to check that over real close and let everyone know what I find. It gives a good place to start. I got my ODB bluetooth adapter and have been running Torque app and sometimes its 13.8-14.2v and sometimes its 14.8-15.3v. I had the high idle happen again today and I got to reconfigure Torque to show different info but the only thing that I saw was the throttle was showing 20%ish (1000-1100rpm) vs 18%ish I see when its normal 750-900rpm.

 

[sonic boom 222]

Charging voltage

Just got my 2015 Sonic back from dealer with a fluctuating voltage problem (13.8 to 15.2) :banana: and flickering headlights at night.. They had it for 3 days before they decided to put a new alternator on it. Problem seems to be solved but I hooked up a digital volt meter to it plugged into the accessory socket (also formerly known as lighter socket) and the voltage stays pretty constant at 14.8 volts while driving during the day. Haven't drove it at night yet. So I am assuming everything is ok for now.

 

[sonic boom 222]

Dealers don't want to do anything if they can't find it in the computer hookup. Took my 2015 Sonic with flickering headlights to them and they said they could find nothing wrong. Went home took video with my iPhone and made up a digital volt meter that I could plug into the accessory receptacle. 13.8 to 15.2 volts continuous fluctuation. Went back with my package and they finally found it was the alternator. Got it back 3 days later.

 

[Lanos2001]

14.8 volts is good. enough to run the vehicle and basically trickle charge the battery.