Cadillac XTS left door initialization not closed error

A customer who has a GM Cadillac XTS car, come to contact us :

"Hello, it’s Philippe I have a mileage of about 20,000 km, with a 2.0T engine and six-speed manual transmission 2014 GM Cadillac XTS sedan. In moving the dashboard prompt the driver information center, “the left rear door glass lifter for an initialization, left rear door is not closed . What tool shall I use to diagnose ? ”

According to obdii365.com engineers experience, they recommend the tool GM MDI Multiple Interface.

And we recommend it to the customer.

Customer placed order on our website and 2 weeks later, he emailed to us again:

” Hello dear, It’s Philippe again. I use the diagnostic detection GM GDS2 software Body Control Unit, found fault code U1544- lost communication with the device 4. Now that maintenance manual, the meaning of the fault code is body control unit and left rear window control unit lost communication.

I suspect that the power supply or the bus left rear window of the control unit is faulty, then the control circuit diagram for examination. Measured and found left rear window of the control unit power supply voltage of 12.46 V, described normal power supply control unit. Measuring the left rear window of the control unit grounding resistance is 0.53Ω, is also normal. Measuring the left rear window of the control unit LIN signal line voltage is 6.2 V, normal. At this point, it can determine the window control unit internal fault.

Thank you very much ”