Battery Light + BRAKE Light followed by P0030

[BL5BO]

2006 Legacy GT

 

I usually drive my car on the weekends, but i went away for a few weeks and the car was sitting.

 

Day 1: Lights and Codes

When i got back and started the car i noticed the Battery Light illuminated and the "BRAKE" light which is for the E-Brake im guessing. I took the car for a drive after starting the car, and then i get a CEL for "P0030" code as well. Cleared the code, and continued to drive. Everything seemed fine and ran good. One thing i did notice was the wiper blade was moving alot slower than normal.

 

Towards the end of my first test drive, i gave it a little gas up to 4k and the Battery Light/Brake lights went away!

 

Day 2: Troubleshooting (Voltmeter Test/CTEK Battery Charger)

So I start watching videos on how to test your batter/alternator. I had a voltmeter and ran some tests. My battery was about 4 months old (Interstate Megatron Plus).

 

The normal volts in (DCV) should read:

Battery (Car Not Running) 12.4/12.6

Battery (Car Running) 14.2/14.4

Battery (Cranking Car) Should not dip under 10 volts.

 

My Readings were:

Car Not Running 11.7

Car Running 11.2

Cranking Car 9.99

 

After this test it was leading towards the alternator not charging and maintaining the battery level at 14 volts.

 

The second Test i did was to make sure the Battery was fine and could hold a charge. I used the CTEK 4.3 Battery Charger. This basically runs your battery through various stages. Basically it doesnt go past stage 5. The battery cant hold a charge. So i charge up the battery, everything checks out, and battery is in good optimal shape!

 

Day 3: Test Drive 2

After making sure the battery was good, i started up the car again. Still got the Battery Light+Brake Light. Gave it a little rev, and the lights went away (Like before). Then i started driving. After about 2 min, i get the CEL again, same P0030 Code. Cleared the code, drove with the AP. DAM was fine, and car drove fine. No dimming in headlights or anything. Still same issue with wiper blade being slower than usual.

 

Resolution Attempt 1:

After testing and ruling out the battery, my last conclusion came back to the alternator. Luckily alternators are only like $120 for these cars, so i bought one from DB electric. Also bought new belt as well. Make sure the output is 110amps, and also my car had the wrong belt on it. it had the 5PK875, but the oem part is suppose to be 5PK874.

 

Removal/Installation was a breeze! 2 bolts and pry the alternator out. The new DB Alternator fit perfectly and everything bolted up. No Issues. Just make sure to feel the tension of the belt before removing. This way when you install the new belt you remember what the tension was before removing. Remember you wanna be more on the flex side than too tight. Too tight is not good.

 

Moment of Truth:

Connected the Battery after installing the new alternator. Got in the car, turned the key, and cranked the car. Started right up, and BAM! NO BATTERY or BRAKE Light! Adios! I let the car run for about 5 minutes inspecting the new belt/alternator for any noises. Everything is good! While the car was running i did run the volt tests as well and was much better!

 

Car Sitting 13

Car Running 14.6

Cranking-Didnt check

 

Test Drive 3: First Test Drive with New Alternator

Did the wiper blade test. much faster now. No CEL. Drove the car with issues! So far so good!

 

Just wanted to share this in case anyone else comes across this type of Issue!

 

Quick Recap:

Problem. Battery+Brake Light On/P0030 Code

Troubleshoot: Voltmeter. Test Battery Volts. Battery volts were much lower than normal. Alternator was not charging the battery while running.

Resolution: Replaced Alternator

[amm203]

Thanks for this. Currently getting intermittent E-Brake/Battery lights at start up that go away within driving about 50 feet.

 

Just today I start my car and get P0700 & P1718 and notice battery voltage is around 13.4 volts while running (via AP) - guessing this is the issue.

 

Edit: Confirmed with Advanced Auto test that I have a bad alternator.

Edited July 19, 2019 by amm203