Twice in the past month the passenger's window on my 04 C5 Z06 has activated to the down position ('rolled itself down') without input. Could this be associated with the notorious 'chassis grounds'? I used to work on avionicis systems on high performance fighter aircraft and experienced similar anomolies with electrical grounds. I have driven this car in the rain (sorry TOOGECKO) and the first occurrence was while it was raining. HELP????

 

If it were me, I would grab the accordian rubber in the door hinge and give it a good shake. Look for damage to the wiring in the same area. If that doesn't give you a clue to where to look further I might take the door panel off and look at the connections to the window motor. I believe that the window motor is controlled by the BCM so you might check the star bus connectors under the footwell on the passenger's side. Clean the serial bus connectors, I believe there are two. Good Luck.

 

streamliner

This may sound weird but bear with me. Ive had so many different cars,,, some things blur.

If I remember correctly the C5 has an express DOWN feature activated by inserting the key in the drivers door and rotating it to the unlock position quickly three times.
I may be hallucinating but, I think our C5 has that feature, Go try it and report back Try three locks and then three unlocks.

I know my VW had it.

If it does, I may have an answer to your issue.. If it doesn't,, I still have some suggestions.

Bill

 

No luck all that did was unlock both doors and pop the trunk open. One of my local Vette buds mentioned a defective window valet module but this car does not have the module.

 

Pull your codes and look for anything that pops up with the door control modules.

 

Ha!! That tells me a LOT!!!

How is your door lock connected to the TRUNK LOCK?????

The sound of the Jeopardy music playing in the background,,,,,,,,,,,,,,,,,,,,,,,,,,,,,, ,,,,,

Answer,,,
The BCM

The BCM interrogates the door lock signals "three rapid pulses" and does a pre programmed routine.

The ONLY way that your window can move by its self is thru the Door control module malfunctioning

OR

The BCM tells it to. YES the BCM can raise and lower the door windows. The VALET module plugs into the OBDII port under the dash. It sort of reprograms the BCM allows the BCM to use the FOB signals to operate the windows.

SO,, my theory is something is wrong with the BCM and the BCM is making that window move.

It is VERY SENSITIVE to moisture / water.. If it is or has been or if itever was wet or damp, there could be some corrosion on the circuit board and that is enough to cause it to brain fart

You can remove the BCM (disconnect the battery first) and carefully take the circuit board out of the box. The board is ESD Sensitive so take all the static discharge precautions.

Look for any corrosion on the circuit board thats not suppose to be there. If you find any, remove it with a nylon brush and alcohol. Use a magnifing glass cause it doesnt take much!!





All it takes is ONE BRIDGE on a logic circuit and all kinds of weird things can happen.

Been there done that!!

 

Actually Bill, that is a feature of the C5. It's even listed in the sticky under C5 secrets. If you rotate the door unlock once, it unlocks the drivers door, twice both doors and three times it pops the trunk. It's a "feature", not a malfunction.

 

C5 Corvette Secrets:


-That you can put your key in the driver's door and turn it twice towards the front to unlock the passenger door and a third time to pop the trunk.

-That you can pop the trunk and also pop the gas cap cover by pulling on metal lines hidden in the back.

-The little slotted cover on the dash behind the steering wheel is where the inside air temperature sensor is located.

-All of the option codes are in the glove box.

-Tire inflation recommended pressures are on the driver's door

-The thing that looks like a little LED near the DIC buttons is a light sensor

-The thing that looks like a little LED near the defroster vent is a UV sensor for determining A/C usage to compensate for the heating effect of the sun

-The build sheet is in the front re-bar

-If you leave your turn signal on, in about 1 minute it will start to ding (loud enough to hear over the stereo) to let you know you have old timers disease.

-You can reset the oil life by pumping the gas pedal 3 times (but not with the engine running)

-Hold down the reset button while on one of the trip odometers and it changes that reading to the miles you've traveled since last starting the engine.

-Hold down the Active Handling button for 5 sec. to engage "Competitive Driving" on cars equipped with active handling (2000 and previous years must be stopped.)

-If you pull the seatbelts all the way out while you're buckled in, they ratchet back in to hold you tighter into the seat.

-Simply remove fuse #2 under the hood and your DRLs will be out permanently. Only thing affected is that when you unlock at night using the key fob your front turn signal lights and back up lights will not flash. Your front turn signals will operate normally, however.

-The side-view mirrors can twist both forward and backward, decreasing the chance of damage if struck.

-There is a release opening with a flap to let air out of the car when the hatch is closed. It is located just above the driver side rear compartment, behind the carpet and on the side of the car. Not that it really works well.

-Also you can ground your amp to a screw/bolt that holds the rear middle compartment to the frame.

-If you have a 6-speed car you can pop the trunk when the car is running by lifting the e-brake.

-There is a spot on the driver side just out of the middle compartment under the carpet for the lug nut key. You should have a compartment on the drivers & passenger’s side (in the trunk) and a center compartment. On the left (drivers) side of the center compartment, on the left side where the center cover fits, there is an 'indent' that holds the wheel lock key.

-If you turn on the headlights, then go to parking light position, the lamps remain up but the headlights are not left on.

-If you have the passive entry feature: If you lock your keys in the car, wait a few minutes and then shake the car. That will unlock the car.

-HUD has a shift light for manuals.

-Hold the PAGE button down and it’ll show MPH, hold it down again and it’ll show RPM’s, hold it down again and it’ll show MPH and RPM, hold it down again and it’ll show MPH, RPM, Gas/Oil Pressure or temperature.

-You can easily shift the M6 trans up or down without the clutch if you match revs. (Not great for longevity, however.)

-You can eject the cd from the in-dash player without turning on any power. Don't even need key in the ignition.

- You can pull the turn signal lever towards you (away from the window) to allow your lights to ‘flash’ which in turn notifies others in front of you that you are going to pass (must have the fog lamp option for this to work).

-The cruise will disengage if you purposely make sharp side to side turns while cruising at say 60-80 mph.

-When the engine is shut off, you can get the odometer reading by turning on the parking lights.

-You can program setting #3 (both memory buttons at once) in the seat memory to run the seat back and steering wheel forward for getting in/out of the car with the engine running.

- If you hate DRL’s you can pull the e-brake ONE click and they go off, or pull the #2 fuse.

 

Thanks for the memory reset.

I knew that the lock did something, I just couldnt remember if did anything with the windows but,,, The BCM does interface with the DCM and the BCM could randomly be telling a DCM to lower the window.

I just dont know why its just ONE window thats being effected.

 

I initially thought I somehow inadvertently activated the button on the console until I tried to intentionally 'inadvertently' activate it. The 2nd occurence was in a right hand 3g turn but I think the first was in straight and level flight. I'll tinker with it and see if I can locate the culprit. It does have after-market door panels the original owner installed. Perhaps he nicked a wire although he is pretty meticulous.

 

The door connectors have a bad history of having issues with the female pins and thats another place to look. Pop out the accordion tubes and fish out the connectors. Disconnect them and examine the female pins por deformation and damage.

You can rebend them if there deformed and loose on the male pin.











BC