Power hatch will not open UNLESS I open the rear driver side door!

[Pete G.]

I have run into a VERY odd situation.  I went out to open my hatch with the outside button and it will not open.  I hear the car unlock but the power hatch does not open.  

After a bunch of testing I figured out that if the REAR DRIVERS SIDE DOOR is open, then the Power Hatch opens as it should.

I close the REAR DRIVERS SIDE DOOR and bam it will not open again.

I am not sure if this is something to do with the "Trunk Lock Actuator Motor" not sensing the door is closed or what.

Any thoughts would really be appreciated.

Also...  Does anyone know of a diagnostics tool that I could purchase that WOULD show me errors with items like the door lock system?

Thank You,

Pete G.

[RobMMcKey]

Weird! Are the other doors unlocked? Was the car key fob used to unlock the car? Window(s) down? 

Sometimes just to totally close all windows, and doors, then relock using the fob.  count to 20 then use fob to unlock the entire car. This may reset the computer.

One more thing : what is the condition of the fob (s) battery(s)?

[Pete G.]

Yes the entire car is unlocked.  I can unlock the car with the key fob OR unlock it with the power hatch button.  The FOB has a pretty new battery.  I recently changed it.  One other thing I noticed.  When I was able to open the power hatch by opening the rear drivers side door.  I then manually closed the hatch and closed all doors.  I went to lock the car and I got the LONG BEEP as if all doors were not closed.  I am replacing the "Trunk Actuator Motor Unit" tomorrow and I will see what happens.  I will try what you said above.

[Pete G.]

Well I replaced the Truck Lock Actuator Motor assembly and problem is still there.  I tried the suggestion above about locking and waiting 20 seconds no change.

I think there is a switch or sensor that is bad.  I do not have ANY WAY to figure this out.

Does anyone know of diagnostics that can be purchased for the car so I can figure this stuff out?

[Pete G.]

Help?

[Pete G.]

I finally was able to connect Techstream up to my RX450h.  And of course it was a nasty communication issue.

I got the following codes:

U0127 - Lost communication with TPM

U0199 - Lost communication with Door Control Module A

U0200 - Lost communication with Door Control Module B

U0208 - Lost communication with Seat Control Module A

U0230 - Lost communication with Rear Gate Module

U1002 - Lost communication with Gateway Module

U1115 - Lost communication with Tilt & Telescopic Module

There has to be a common denominator when it comes to all of these devices not being able to communicate over the bus.

Any help would be appreciated.  I do not have a service manual so this makes it very difficult.

-Pete

[Pete G.]

New finding....  When I open the left rear door all of the communication is restored for the above items.  It is now clear that the left rear door must have some kind of short in it.

What would be super helpful is a can bus schematic or wiring diagram for the car.  It is REALLY hard to find anything.