[BANSH1]

We have a 2010 Chevy Malibu 4 cylinder that has an electrical issue i'm tired of throwing parts at. Anytime your driving the vehicle around and decide to turn on the A/C it will eventually throw a p1682 code forcing the car into engine reduced power mode, making the vehicle run terrible so you have to pull off to the side. If you clear the code and start the car back up it will run just fine. Also if you never turn on the A/C it wont throw that code again. I've also noticed if you turn on the A/C that cooling fans will turn on as they should, but once you turn off the A/C the fans will continue to run and after a little while it will throw the p1682 code. So that rules out the idea that maybe my A/C compressor is bad, forcing the serpentine belt to slip, causing my alternator to not charge properly, making the computer see the voltage drop between the two ignition wires its monitoring. I'm stumped on this one.

So one more time, p1682 only activates when the A/C cooling fans are running (not immediately, but it eventually will, its mostly a guessing game). We've already replaced the cooling fans even though the code is related to a voltage difference between to ignition wires.


Any suggestions or comments are greatly appreciated.

 

[repairman54]

Engine-codes.com will give a little more info. . Did you read the fretting corrosion sticky at the top? BCM connector is a source of a lot of weird codes. Connections both power and ground would be a starting point after cleaning BCM connectors. DeOxit is always in my garage for connectors.

 

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Did you ever find a fix to this problem?

 

[BANSH1]

Yes I did, turned out to be the fuse box, I didn’t do a good job of diagnosing and just started throwing parts at the car so I couldn’t give you a good direction on what to test to make sure it is that. I purchased a used one off of eBay and it made the issue go away.

 

[[email protected]]

Ok I’ll check into replacing mine the problem seemed to go away since I drove last night and this morning just gonna keep monitoring mine until I’m sure

 

[BANSH1]

I noticed that when I drove the car on a cool day it wouldn’t trigger the code, but as soon as the days temperature started to heat up, coupled with driving around for a few hours the code would set. I believe that one of the fuse boxes internal copper wires would disconnect due to the heat expanding it. There were signs of burnt connections underneath on the female wire harness ( the connector in the photo was the very bottom harness on the fuse box.) hopefully the photo included is viewable.

 

[DrivenDaily]

Oh, wow, yeah I can see it, and it doesn't look good. As I'm sure you're aware, discoloration like that is most likely caused by extended periods of high amperage use, but not high enough to blow the fuse.

A junkyard donor fuse box might be a good place for another housing as well as undamaged terminals. If you go that route, clip the wires back a few inches (or as far back as you want), then solder and heat-shrink.

You may also want to consider finding out what all is on those circuits and seeing if there is something aftermarket that has been added, or if something stock is starting to fail but hasn't completely died yet.

 

[[email protected]]

I noticed that when I drove the car on a cool day it wouldn’t trigger the code, but as soon as the days temperature started to heat up, coupled with driving around for a few hours the code would set. I believe that one of the fuse boxes internal copper wires would disconnect due to the heat expanding it. There were signs of burnt connections underneath on the female wire harness ( the connector in the photo was the very bottom harness on the fuse box.) hopefully the photo included is viewable. View attachment 67185

Yea I see the burnt connections. So would you recommend me gettin a new fuse box from eBay or something or a used one from the junkyard? Also was replacing it a complicated task? Or should I have a mechanic do it for me?

 

[[email protected]]

Btw do I replace the one under the hood, near the passenger side, or in the trunk?

 

[BANSH1]

Under the hood

 

[[email protected]]

Ok at my local junkyard now bouta replace it.. hopefully It works

 

[[email protected]]

It’s been about a week since the fuse box replacement and everything works fine.. I really appreciate the help.. I also realized the bolt holding the rear fuse housing was really loose..that could have been the problem but I already bought a non refundable fuse box from the junkyard

 

[DrivenDaily]

Probably best that you replaced it anyhow, since that bolt holding things together may have allowed certain connections to become loose enough to cause overheating of the connectors. The damage may also have prevented a repair from lasting long enough, failing again in too short a time.

Glad you got it fixed, and thanks for coming back to share the solution!

 

[[email protected]]

Yeah and I appreciate the forum because I took it to professional mechanics and no one could find a solution everyone wanted to replace parts that weren’t even an issue. So I’m the long run I saved a lot of money and time here.

 

[Avidsky]

I noticed that when I drove the car on a cool day it wouldn’t trigger the code, but as soon as the days temperature started to heat up, coupled with driving around for a few hours the code would set. I believe that one of the fuse boxes internal copper wires would disconnect due to the heat expanding it. There were signs of burnt connections underneath on the female wire harness ( the connector in the photo was the very bottom harness on the fuse box.) hopefully the photo included is viewable. View attachment 67185

Everything you described is exactly what’s happening with my car. Except that it only takes about 20-30 minutes on a day over 75° to shut off on me. Also, we didn’t see any burnt connections when we were looking at the fuse box. Has this fix still held up? Wondering if we should go through the trouble or just say forget it with this car.

 

[Avidsky]

Yeah and I appreciate the forum because I took it to professional mechanics and no one could find a solution everyone wanted to replace parts that weren’t even an issue. So I’m the long run I saved a lot of money and time here.

Did this fix hold up for you or did it happen again?

 

[American Made Chevy89]

This is happening with my vehicle as well. It started when i was in idle, on park and a/c on. The car was wanting to go like i had the throttle open a little bit. At first i cleaned the throttle body and reset the battery, started up and drove it home. Then i got a knock sensor code so i replaced the sensor. Now when it goes into "limp" mode the engine doesnt shake violently like it was but engine reduce power is definitely still the issue.

 

[American Made Chevy89]

I have tried to get the wiring diagrams but all i can get is a screw shot from a video on YouTube. I have a 2012 2.4L. My 2 power wires running from ignition switch to pcm are white and pink. Need to check those circuit voltages, as well as power going to the ecm through both circuits ( fuse 2 and 16). Fuse 16 is connected to the run/crank relay which is the secondary circuit provided to the pcm. I need to check the fusebox for signs of wear/ damage and possibly apply the pcm/ecu comnectors with dielectric grease. I will let you know my status and what i find. Btw i appreciate the tip about resetting the code that allowed me to get home after driving around and getting stuck waiting for my engine to cool down.

 

[repairman54]

Subscription for your car on Alldatadiy.com will give you every diagram and then some. It's the shop manual.
Very few free ones online that are worth a darn.

 

[American Made Chevy89]

Thank you might just need it. Bought my car a year ago and still paying on it, however it's past warranty so I'll have to work on it myself. I don't trust the dealer unless I'm bringing in for maintenance on something specific.

And by the way just wanted to add in that I've had to bypass the wire for my fuel pump on my 06 malibu when it wasn't starting and had similar issues but wasn't the same code. The wire and connector kept getting hot and burning causing poor connection, stalling, no start, rough idle,then run fine for a while and stall out. bypassing the fuse box with a fuse, wires and its own ground circuit made a perfect fix. Of course you can't to keep your circuit in line with the fuel pump relay if you are having this issue. Another thing to check.