Left Rear Door Problems

[dugg]

left rear door's window and lock cannot be operated from any location, no power to courtesy light either, left rear door does not lock when shifted to drive. Possible door computer problem?? 2005 ls430 with 26,000 miles. thanks

[curiousB]

Sounds like broken wire in door hinge. Not sure wiring but if the windows, light, and lock share a common ground wire back through the door hinge this could explain why lights, lock, and light all fail together. Might have to open up door panel to check.

Here’s a suggestion, remove bezel from door courtesy light and see if you can determine which pin of bulb is ground and use that point to temporarily feed a ground line to the door circuits to check out broken door wire hinge theory. Easier than dismantling entire door.

Another idea is to wiggle wire harness in door and look at courtesy light. Does it flicker? A broken wire would likely be an intermittent and might show up by flexing harness some.

[Robert Young]

Unfortunately, you might not be lucky enough with a simple wiring fix. Lexus reduced the number of wires for each door by using ECUs (simple computer like devices). There are ECUs all over the car, including 2 for the driver's seat, 1 for the moonroof, etc. The door units are on a BEAN door bus, pages 153 and 154 of the 2006 wiring diagram, see attached. LR_Door_Pages_from_Lexus_Wiring_Diagram.pdf