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Discussion Starter · #1 ·
Call me paranoid if you will however I just replaced a lot of my BCM (Body Control Module) circuitry due to a fuse failing to blow costing me $450. Since I got my car back I've noticed a few issues only getting worse, my front passenger side window has been very slow and loud, especially going down. My headlights make a weird humming/buzzing noise.

Just now I noticed after parking my car a weird rough idled low noise the motor made, so I played. And when rolling windows down, playing with heat fan speeds, rear/side view mirror defrost that when turning on the flux of electrical load would seem to drop the RPMs to go from td normal idle of 800-850 RPMs to roughly 600-650 RPMs.

I've read a lot on here about a "negative batter cable" causing issues for others, is this my problem? Battery on its last leg? Should I read the OBDi (I think that's what it's called) monitor


2011 Chevy Cruze LTZ 1.4L Turbo
 

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What blew out that took out the BCM? When the headlights buzz, is that in DRL mode or normal headlight on mode?
 

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Discussion Starter · #3 ·
What blew out that took out the BCM? When the headlights buzz, is that in DRL mode or normal headlight on mode?
The subwoofer wiring shorted to ground, didn't blow the specific fuse dedicated to that, and I'm running LED headlamps, same bulb and it never mad sounds or gave issue before recent


2011 Chevy Cruze LTZ 1.4L Turbo
 

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Knowing if the system has stored codes would be a first step to identifying what's amiss. If you don't have a code reader, most auto parts stores will read them for you. If it were my car, I'd also return the headlights to OEM also. I assume the sub is disconnected at this point?
 

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Put your OEM headlights back in while you work out the electrical issues. It's easier to troubleshoot with a "standard" configuration. Once you're back to stock and your electrical issues are resolved then you can start adding one modification at a time back to the system.
 

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Discussion Starter · #6 ·
Put your OEM headlights back in while you work out the electrical issues. It's easier to troubleshoot with a "standard" configuration. Once you're back to stock and your electrical issues are resolved then you can start adding one modification at a time back to the system.
The head lights don't set off a code, I took license plate lamps out cause those were though, I don't have the OEM bulbs and wiring anymore


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Dangers of messing with wiring in modern cars. That one short to ground could have partially fried dozens of circuits.
 
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Discussion Starter · #8 ·
I had the whole ecu pulled out and worked on for over a week and have a report of a circuit replaced and codes that are still on are only for the LED done, tail lights trunk and glove box lights so I don't think it's that, what problems does the negative battery cable cause? Anything similar?


2011 Chevy Cruze LTZ 1.4L Turbo
 

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What are the codes?

And I'm trying to figure out how a short to ground in a sub would cause a problem with the BCM. How was the amp powered and grounded? Or did it short to something else and not ground?
 

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What are the codes?

And I'm trying to figure out how a short to ground in a sub would cause a problem with the BCM. How was the amp powered and grounded? Or did it short to something else and not ground?
With it being a floating ground, I thought anything that surged along the "ground" would instantly be able to travel backwards into all other devices sharing that same point.

Then again it's been 20 years since I was in electrical school, and I'm in software now so I'm quite likely incorrect. So from a common sense position, I'm going with "arcing is bad"...lol
 

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With it being a floating ground, I thought anything that surged along the "ground" would instantly be able to travel backwards into all other devices sharing that same point.
If it shorted to the frame, I'd expect it to either go back to the battery or to the amp - in which case I'd ask how the amp was grounded. Same for the power lead.

While electricity does generally follow the path of least resistance, put enough amps into it and it will take some side-streets to avoid the congestion on the main route.
 

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Without any stored codes, wecan't offer much help other than conjecture. The negative battery cable can be the source of many electircal problems in the Cruze and it's a well documented issue. Who did the work on your car?. I'm guessing you've entered into the YOYO zone. You're On Your Own.
 
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