low voltage

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Sep 10, 2022 | 10:42 AM

Mikedoc

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Joined: Aug 2003

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From: Sayreville, NJ

low voltage

I need some help, I have an issue with a "low voltage" message and reading. I have checked the battery and changed it and have had the alternator checked and tested. This "low voltage" message comes up out of nowhere, even without the car running. When it does come up I also get the oil temp flickering from hot to cold to nothing and get the codes B1542, and B1543. I have changed the sensor and it still happened. It does rectify itself but then comes back. Sometimes with the car hot sometimes with the car cold. No issues starting it up at all. Can someone help me with a procedure to test and check this out. Thanks.

Sep 10, 2022 | 10:54 AM

C5 Diag

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From: Cape Coral, Florida

When you turn the key on and select battery volts through the DIC what do you read ??...if IPC sees less than 10 volts for 5 seconds the message appears... the DTC's are for your temp sensor...do you own a DVOM ??...if you would have caught me 2 years ago I was in Union Beach !!

Last edited by C5 Diag; Sep 10, 2022 at 11:07 AM.

Sep 10, 2022 | 12:44 PM

Mikedoc

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From: Sayreville, NJ

Quote:

Originally Posted by C5 Diag

I have a volt meter in the lighter and it is always around 12.7. I have a tender on the car when I'm not driving it, it is not my daily. The problem started a while ago where the voltage gauge drops all the way to 0 but the lighter voltage stays at 12.7 when the car is off and around 13.5 when the car is running. I did some reading on the forum and saw the oil temp sensor come up in conversations. So I started driving around with the oil temp selected on the dash. And there it was the oil temp started blinking high and low and the voltage gauge dropped to 0. So I thought the sensor was bad and changed it, but it didn't fix the issue. I do have headers on the car, no sure if I have a spot that shorts every once in a while. I have read alot of your posts and figured you might be the right person to talk to about troubleshooting this. I appreciate your help, wish you were still in Union Beach LOL.

Sep 10, 2022 | 02:38 PM

C5 Diag

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From: Cape Coral, Florida

We are looking at the IP circuit so don't worry about measuring voltage at the lighter...does this low voltage message happen frequently ??...do you have a multimeter ??

Sep 10, 2022 | 03:24 PM

TheBac

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From: Mid-Michigan

I would still look at the ignition switch, at least pull it and check the terminals in it. Could be one set is burnt. Doesnt cost anything to check it, just time.

Sep 11, 2022 | 08:46 AM

Mikedoc

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From: Sayreville, NJ

Ok, yes I have a multimeter, where should I test.

Sep 11, 2022 | 09:30 AM

Mikedoc

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From: Sayreville, NJ

Also the "low voltage" message and voltage gauge on the cluster drop to 0 is totally random. Sometimes it happens alot, other times it would be fine for a few days. It happens when the car is running and when the car is sitting in accessory mode. Very frustrating.

Sep 11, 2022 | 10:26 AM

C5 Diag

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From: Cape Coral, Florida

When the Low Voltage message appears place one lead of the DVOM on battery POSITIVE and the other lead if your DVOM lead is long enough on one of the 2 metal test points on top of Fuse 25 (BCM1 and IPC) located in the IP fuse box by the passenger side footwell...don't worry is the DVOM reads a negative voltage just read the voltage.