Hey everyone, I've been stuck on my G for about a month, trying to figure out why the motor turns off. It’s showing no lights at all and no codes, and I’m at a loss. About a month ago, on my way home from work, my car started to hesitate during acceleration. Around 10 minutes into my drive, the acceleration felt completely off, and then the motor turned off, but all the electronics kept running. I immediately checked for codes, but none appeared. Two days later, a code finally showed up: P0605. I took my car to my mechanic, who checked it and noticed my battery terminal was loose. He tightened it, which cleared the code, and the car drove well for a week. After a week without issues, the car began to show signs of turning off again, with poor acceleration and difficult start-ups. I checked for codes again, but none appeared. The terminals looked tight, so I suspected it might be the battery. I took it to AutoZone, and their machine indicated the battery was bad, so I replaced it. The car ran well again for a while, but the issue has returned. Now, a new code has appeared: P1550. I’m starting to think it might be a bad ECM, but this new code has me questioning that. Any help would be greatly appreciated. Thanks!

 

P1550 is the battery current sensor fail code.
The battery current sensor is a ring that the battery ground wire runs through. It senses the current going to ground and along with the ECU controls the output of the alternator. Primary purpose is to run the alternator at as low of a load as possible to increase fuel mileage.
I am not an expert on this, but if it failed, it might cause a condition that makes the ECU run the alternator at a low output, thus causing your battery to drain.
Some bsaic apps like tourque pro coupled with an OBD adaptor allow you to monitor charging output. I imagine there are other methods as well, i just havent explored the charging system in any depth or detail.

 

I'd suggest getting out a wire brush and cleaning all the battery terminals and the grounds on the car. This includes the chassis grounds and use some dielectric grease when you bolt it up again.