Test results interpretation needed
Have a 2011 Infiniti G37 X sedan with inop door locks and power windows. No codes in BCM. The drivers window does work from the drivers door switch. All 4 window are auto and anti pinch. All 4 windows have individual switches that are modules and are all connected via a single comm line to the BCM . I can use the powers an grounds at each switch module connector and run the windows up and down manually. The door locks work with the fob and can be commanded with scanner from the BCM. I have a Matco Maximus 2.0 and a Snap On Modis Ultra both updated to the latest software. There is no data for the power windows in the BCM an there is no option for any of the window switch modules as a communicatable module in either scanner. Is this normal or would a Nissan tool at least have power window data in the BCM? I then scoped the comm line. This is what I have for the comm line. Here is the pattern zoomed out. Its way too perfect. Almost like a diag pulse or something??
Here is each individual pulse. Its always the exact pattern every pulse.
Actuating all the invidual switches creates no difference to the signal. On the driver switch actuating the driver, passenger, and left rear switches creates no change. However actuating the right rear window switch from the driver window switch creates this extra pulse although the right rear has no response.
Nissan service info show the comm signal waveform as sometimes a 0-12v and sometimes a 2-12v. I only have 2-12 volt square wave.
Also the door lock switches on both front door window switches are comm signal on the same line to the BCM. The BCM data show no response from either switch and the comm signal on scope also no change when pressed. If I disconnect all 4 door switches and BCM the signal goes to 0 volts so I assume no shorts. The driver window switch module is the only creating this pulse. All the other modules only output 12volts when connected individually including the BCM. The pulse is the same with all the modules connected or just the driver door switch module connected. The BCM has green corrosion on the comm pin but I took the BCM apart and it is clean. I would think if it was causing an issue there would not be a clean 12 v from the BCM. I cleaned the terminal with no change. Is this network consided a K line or a LIN bus? It looks LIN to me but not sure . My guess is the drivers window switch is the master and nothing is working because its not waking anyone up or even functioning at all. Anyway I believe it needs a drivers master window switch. But I would like some other insite. Thanks guys
I believe you're on the right track with the switch. When you hold down the key unlock, does the passenger window go down as well as the driver window?
Your talking about the fob? Let me see. Also I reposted this as a bounty if your interested.
Thats ok buddy ;) let me know. Although I still believe the master switch is the culprit based on all the info provided. I would probably scope the serial line while doing this too. I believe the serial output of the driver switch to the rest of the modules is no good.
I assume your talking about the fob unlock button correct? Anyway no ,neither window responds to holding the fob button. This is a sedan with A pillar that goes all the way around the window if that matters for the function your talking about.
This is kind of a weird one. What Mario was explaining I think is if you hold the unlock button on the key fob for 5-10 seconds the front 2 windows should roll down. I find it weird that each door has a module of its own but will still not roll down on its own switch. Why would it have to communicate anything on the network if its own module would be sending power and ground for up or down to…
yes, SI shows that serial comms is used to command the rest of the modules from the master switch. thats my reasoning behind it. holding the key fob should send a command from the bcm to the master switch, and from there to the passenger window module(via serial comms). I'm expecting to see the driver window operate but no comms and passenger window operation. if I'm not mistaken.
yea I would think the drivers window would roll down but not the passenger window since it seems like that module is not working correctly and sending out data.
Thanks guys . Im going to quote a master window switch and see what happens.
Hey Mario,so the lady just bought the car and now the warranty company is coming out to" review " it because it has so many other problems. So im still waiting. I was at a John Thorton class last week and believes we are also on the right track. Do I need to award the bounty now or wait till I have a better answer? And awesome video with Brandon , Mario! Him explaining the shorter pull on the…