How JustAnswer Works:
  • Ask an Expert
    Experts are full of valuable knowledge and are ready to help with any question. Credentials confirmed by a Fortune 500 verification firm.
  • Get a Professional Answer
    Via email, text message, or notification as you wait on our site.
    Ask follow up questions if you need to.
  • 100% Satisfaction Guarantee
    Rate the answer you receive.
Ask Jake Your Own Question
Jake
Jake, Nissan Technician
Category: Nissan
Satisfied Customers: 3655
Experience:  Experienced collision repair technician, Pulaski Tech graduate and DSM hobbyist.
20440119
Type Your Nissan Question Here...
Jake is online now
A new question is answered every 9 seconds

2007 Nissan Quest - the rear tailgate opens by itself when

Customer Question

2007 Nissan Quest - the rear tailgate opens by itself when the car is not running and either engine is off and car locked. Now when the ignition is turned off or on .. the tailgate opens if it is closed and closes if it is open by itself. then it keeps opening and closing by itself. When this happens when the car is locked and security alarm is armed - the alarm comes on sometimes.
Submitted: 3 months ago.
Category: Nissan
Expert:  Jake replied 3 months ago.

Hey there, thanks for the question.

MORE OFTEN than not this is the result of a faulty key FOB. The fault in the FOB itself usually results form the FOB getting wet or getting sand in it.

The best way to rule out the FOB is to remove the key from the FOB and see if the problem dissapears. If so then you KNOW the FOB was at fault.

Customer: replied 3 months ago.
Have already done that ... separated the FOB from the key. The FOB is 100 ft away in the house. Operating with just the key.
Customer: replied 3 months ago.
turn the ignition on or off ..engine on or off ... upon off the tailgate starts to open and close ...
Expert:  Jake replied 3 months ago.

when it opens and closes though it operates normally? meaning the latch pulls the door fully closed etc?

does it beep at all when it happens?

Customer: replied 3 months ago.
it closes and opens normally. It will be closed with the power off ignition off ... car locked ... it will open by itself sometimes. but invariably now when I turn the ignition off ... the door starts to close and open by itself.
Customer: replied 3 months ago.
Looks like it is getting some spurious signal to open/close the trunk of the car when the ignition is turned off. Some loose connection somewhere...
Customer: replied 3 months ago.
looks like the motor for the tailgate gets a toggle signal ..to start or reverse the motor... where does it get this signal from ? there are multiple sources that can trigger this signal ... can you check the wiring diagram of this car and suggest a diagnosis ?
Customer: replied 3 months ago.
do you know where the back doo control unit is on the Nissan Quest 2007 ?
Expert:  Jake replied 3 months ago.

both the signal reciever and the control unit on this year model should be at the top of the trunk door drivers and passengers side.

be a good time to check for any water intrusion or corrosion, could be as simple as that.

Customer: replied 3 months ago.
you mean the liftgate door that goes up and down or on the body itself where the door is hinged and closes .... ?
Expert:  Jake replied 3 months ago.

here

Customer: replied 3 months ago.
am looking to see the area around Backdoor Control Unit B55 ? If yes which part of the Van is it located ? Is it on he drivers side in the LH plillar above the Knee area where the driver sits ? or is it in the left H rear pillar above the wheel where the motor is located ? Looks like we might be getting somewhere with this problem :-)
Customer: replied 3 months ago.
Looks like both #6 BCM and #11 Back door control unit are located in the lower part of the front LH Pillar. Please confirm. Do you have instructions to open that area up and see if there is any corrosion and/or water ?
Expert:  Jake replied 3 months ago.
No, the BCM is under the dash area, but the back door control unit is at the rear.
The rear control unit pic shows the rear door up with body panel and door panels removed.
Customer: replied 3 months ago.
the Back Door control Unit B55 is in the body left rear panel ... not the rear door. Please confirm. So I would not have to remove anything from the door. Only panel where the motor is also located ? please confirm.Your thinking is that there might be some corrosion or water near the Back Door Control Unit that is causing it to malfunction ?
Expert:  Jake replied 3 months ago.
referring to your question earlier about a toggle signal, these motors get their signals from the back door control unit. The control unit interprets the signals from the FOB receiver or switches through pulse or continuity.
In case of a restriction or failed struts the motor can detect a pinch condition in the encoder or a close start position and retract it.
Expert:  Jake replied 3 months ago.
Yours seems completely random, it's not starting open the close on its own from weak stays or anything like that, yours just opens and closes whenever it feels like it.
Customer: replied 3 months ago.
It could be... water related.. About 2 months back I had left the moon roof open over night ..tilted up. It rained that night. Then a couple of days later when I opened the rear liftgate ... water poured down from the top of the door area ... middle area where the hinges are. I suspect some water may have come down the area of the moon roof and gone down to the Back Door Control Unit area. Yesterday also it rained pretty hard at night. This happened today.So my challenge is to locate the LiftGate COntrol Unit or Module. Do you have any instructions or pictures for me to use to open that area so that I may be able to open the panels without damaging them ? Thx.
Customer: replied 3 months ago.
There was some water under the carpet right in front of the drivers seat as well. I opened that area up and just the carpet padding was a bit wet ... up the pillar I did not see any rust or anything like that.
Expert:  Jake replied 3 months ago.
I am on my way home from dinner soon as I get home I will send a request for a secure email exchange once we swap email addresses I can send you all the documentation you need from the factory service manual the files are far too large for this website
Customer: replied 3 months ago.
Can you send me the Nissan Part Number for the Back Door Control Unit -- I peeked at it I think. There was no corrosion there or water. Just want to confirm.Also could the Pinch strips be a problem ... some water or something in them that may be shorting them ... hence a signal going to the motor. and reason this does not happen when car is running . is probably because of some safety override ... to ensure that the liftgate does not open when the car is running. When we turn it of .. the pinch is there and therefore it sends a toggle signal to the motor. Is there a way to check the pinch strips out ?
Expert:  Jake replied 3 months ago.

If the Pinch strips were an issue, it would beep and stop or reverse when opening. It wouldn't randomly open and close.

Expert:  Jake replied 3 months ago.

I tried to send you an offer for an email exchange, but I don't show you accepted it.

If you don't want the documentation I am fine with that, but making sure you got the offer as I set it for the lowest amount the site allows me to.

Customer: replied 3 months ago.
Can you send me the Nissan Part Number for the Back Door Control Unit -- I peeked at it I think. There was no corrosion there or water. Just want to confirm.
Customer: replied 3 months ago.
I have not solved the problem yet. Can you please send me the part number of the BCDU? This is the 3rd time I am requesting this information.
Expert:  Jake replied 3 months ago.
Sorry my apologies, let me have your VIN and I'll look it up for you.
Customer: replied 3 months ago.
2007 Nissan Quest. VIN .. 5n1bv28u57n121807
Expert:  Jake replied 3 months ago.
82580-5Z20A
Expert:  Jake replied 3 months ago.
It's actually connected to the motor on this year and model. If you look at the image I have you where where it's just below the motor it's actually part of it not seperately.
Expert:  Jake replied 3 months ago.
if you opened the rear hatch and removed the left side trim piece and viewed the motor then YES you viewed the control unit as well.
Expert:  Jake replied 3 months ago.
Let me know if you need something else. Happy to assist

Related Nissan Questions