# Cruze Power Window Issue



## jderry93 (Sep 17, 2020)

Hello,

One of the big things on my "to-do" list on my 2012 Cruze LT is get the power windows working as they should.

The drivers "master" switch will only control the drivers front window currently. This car has express up and down.
The other 3 switches control their respective windows as they should.

I am thinking this must be something to do with the BCM communication between the switches, but wasn't sure if this was a common issue Cruze owners see.

Any help is appreciated!


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## plano-doug (Jul 1, 2015)

jderry93 said:


> The drivers "master" switch will only control the drivers front window currently. This car has express up and down.
> 
> The other 3 switches control their respective windows as they should.


I think you're on the right track with BCM communications. I've attached some drawings for the windows.

In the drawings, note that RPO AXG refers to driver's window express up/down. AEC is driver's window express down.

My first thought was wiring. But for both the passenger and rear windows to not be working, two different wires would need to be broken, 6134 and 6135.

The wires in the driver's door jamb are the most likely to fail, since those wires get flexed the most, but I doubt two are broken.

Other than inspecting the wires at the driver's switch and at the BCM, I'm not sure what else can be done without specialized test equipment. 

You would like to see if the BCM is receiving and recognizing the messages from the driver's switch. 

I think an app running on a smart phone with a cable to the data link connector (X84) in the dash can do that. (I need to get that going on my phone, too.)

Hopefully, others here will chime in. 

I've been studying the communications networks in the Cruze, but am far from being an expert. The windows use the Linear Interconnect Network (LIN) bus. It is a one-wire, multi-drop, bi-directional bus, running at ~10.4 kbps. There are 6 separate instances of it in the 2012 (and 2013), but only 2 are used by the windows, 6134 (LIN bus 3) and 6135 (LIN bus 4). 

The basic flow is that the driver's switch talks to the BCM on 6134. The BCM then talks to the passenger window motor on 6134, and to the rear window motors on 6135.

HTH.
Doug

.


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## jderry93 (Sep 17, 2020)

plano-doug said:


> I think you're on the right track with BCM communications. I've attached some drawings for the windows.
> 
> In the drawings, note that RPO AXG refers to driver's window express up/down. AEC is driver's window express down.
> 
> ...



Doug,

I will print these off and take a look after work today.
I really appreciate the additional information and drawings!


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## JLL (Sep 12, 2017)

I'd take the switch out and test it before I'd go through all the wiring.


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## jderry93 (Sep 17, 2020)

JLL said:


> I'd take the switch out and test it before I'd go through all the wiring.


I have a new switch from the dealer, same issue with both.

My lockout is not illuminating also.


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## jderry93 (Sep 17, 2020)

I have power where I should and the ground wire has continuity to the chassis ground. 

The lack of window lock illumination on both switches as well as this make me think it's BCM / Communion line related. 

I am not sure how to troubleshoot this without a dealer scan tool.


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## jderry93 (Sep 17, 2020)

I am not a big fan of throwing parts at an issue, however, I decided to swap out the negative battery cable for the newer style as well as replace the under-hood fuse box that seems to be a common point of concern.

If I do not see any results from these two I will probably have to get access to a higher end scan tool that can communicate with the BCM.


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## plano-doug (Jul 1, 2015)

jderry93 said:


> If I do not see any results from these two I will probably have to get access to a higher end scan tool that can communicate with the BCM.


Sorry I'm late to respond. I lost track of this thread.

Looking at the drawings, I don't see much else you can do without a scan tool, like you mentioned.

About the only other thing I might try would be to put an oscilloscope on the bus wire from the switch to the BCM. I'm not suggesting you manually decode the messages, but, if you have a scope, you might be able to see whether there's a nice, rectangular waveform on the bus when you hit the switch, or if instead there's a bunch of noise, or maybe nothing at all.

There's a remote possibility the switch is sending a good waveform with the wrong message, but that would be very unlikely. That would certainly be a very unusual failure mode.

So poking around with a scope might help you rule out the switch, or pinpoint it as the likely culprit. Otherwise, some sort of scan tool is needed to determine where the messages are _not _getting thru.

Doug

.


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## jderry93 (Sep 17, 2020)

plano-doug said:


> Sorry I'm late to respond. I lost track of this thread.
> 
> Looking at the drawings, I don't see much else you can do without a scan tool, like you mentioned.
> 
> ...



Hello Doug,

I appreciate the response. I got a scan tool that can read BCM codes.
It says it lost communication with device 8 (passenger window switch).

After checking for continuity to with ground, it does appear my com line from the passenger window switch is shorted to ground.

I removed the door harness from the body. The body side is shorted to ground.
I do not have a short to ground at the BCM side of the wire, so I am thinking it may be near J314 on the drawing you provided. I am looking into where that junction is now.


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## plano-doug (Jul 1, 2015)

jderry93 said:


> Hello Doug,
> 
> I appreciate the response. I got a scan tool that can read BCM codes.
> It says it lost communication with device 8 (passenger window switch).
> ...


I will agree, there's something wonky around J314. If it's shorted to ground, I would expect it to interfere with driver control of the passenger window, and maybe also interfere with driver control of the driver's window, too.

Can you look on the RPO sticker in the glove box and see whether AXG or AEC is there? That affects which schematic applies for the driver's door.

To be clear, you said the driver's switch does not work on the rear windows, either, right?

Doug

.


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## jderry93 (Sep 17, 2020)

Doug, 

I will check the RPO code tomorrow morning. 

Nothing but the drivers window works from that switch currently, including the lock out.


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## jderry93 (Sep 17, 2020)

It has the AXG RPO


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## plano-doug (Jul 1, 2015)

.


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## jderry93 (Sep 17, 2020)

I found the junction, it is pretty close to the drivers rocker panel.
It appears to be a soldered connection in heat shrink. I will disassemble it and repair it after work today.

I know I can't be sure, but it does not seem like it could be shorted to ground inside of the heat shrink.


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## jderry93 (Sep 17, 2020)

Well after all of this I found the issue.
This was inside the drivers door. When I measured voltage without a switch plugged in it was ~12.5V.

Plugged the switch in and it would drop to ~2.5V. Plugged another switch in, same deal.

Jumpered 12V from the fuse panel in the dash to the switch and it worked as expected.
The master had insufficient voltage to communicate with the slaves and bcm properly.


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## plano-doug (Jul 1, 2015)

jderry93 said:


> Well after all of this I found the issue.
> This was inside the drivers door. When I measured voltage without a switch plugged in it was ~12.5V.
> 
> Plugged the switch in and it would drop to ~2.5V. Plugged another switch in, same deal.
> ...


Kudos on solving the problem !

So you found the wires twisted together like that? (Or that's part of the diagnostic setup?) For sure, the wires aren't well connected, so I can see the voltage dropping as soon as current tries to flow to the window motor.

Is that the RD/D-GN wire (#1540) supplying +12V to the window switch? 

Glad you got it resolved.

Doug

.


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## jderry93 (Sep 17, 2020)

Doug, 

That is as I found in. Barely twisted together and not even taped separately! 

Yes it's the 12V to the switch.


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## plano-doug (Jul 1, 2015)

jderry93 said:


> Yes it's the 12V to the switch.


I can see the bad wiring affecting driver control of the other three windows. That makes sense. I'm surprised it didn't affect control of the driver's window, too.

Doug

.


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## pilbeam100 (Jun 4, 2021)

Hello, I have a similar issue. My 2012 Cruze w Express up and down , the Driver window has just stopped the other 3 still work. New regulator Assy, New Switch, same thing Any ideas here? I do have 12v to the motor


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## Blasirl (Mar 31, 2015)

pilbeam100 said:


> Hello, I have a similar issue. My 2012 Cruze w Express up and down , the Driver window has just stopped the other 3 still work. New regulator Assy, New Switch, same thing Any ideas here? I do have 12v to the motor


Welcome Aboard!

Has any damage occurred or work been done to the door or under the dash ? 

Don't forget to introduce yourself and your Cruze here.


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## pilbeam100 (Jun 4, 2021)

Blasirl said:


> Welcome Aboard!
> 
> Has any damage occurred or work been done to the door or under the dash ?
> 
> Don't forget to introduce yourself and your Cruze here.


I found the problem in harness 6" from motor


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## Blasirl (Mar 31, 2015)

pilbeam100 said:


> I found the problem in harness 6" from motor
> View attachment 292516


How did it get pinched?


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## pilbeam100 (Jun 4, 2021)

I suspect nicked at factory then 9 years for the green to set in


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