Diagnosis of a bad power sliding door motor can be tricky. The system that includes the door motor can be quite complex, with all sorts of possible faults. And there are several ways the motor and drive system can break. A technician will attempt to cycle the sliding door with the switch. If it works, but there are strange noises coming from the door or the rollers and tracks, the technician will disassemble the door to locate the source of the noise. If the door does not work, and depending on the symptoms, the technician can use a scan tool to check the BCM for faults, manually open the door and remove the trim panel for access to observe the system of door mechanisms, and remove door components to be tested with a multimeter. Sometimes, a problem that seems to be a faulty door motor, is actually another component in the system that is keeping the motor from engaging, such as a failing actuator for the lock and latch. The drive system - cables, chain, rollers, and track - will also be inspected for debris or damage.

The procedure to replace a power sliding door motor will vary depending on where the motor is located in the vehicle. It is found inside the sliding door on some models, and inside the quarter panel of others. A technician will open the door and remove the interior trim panel, and remove the interior quarter panel trim inside the back of the van if necessary. With the interior panel(s) removed, the technician will disconnect and remove any other components that are in the way, such as the door glass, rear seats, or the rear heater fan assembly. The inner door shell may include a mounting panel to which the motor, actuators, cables, window regulator, and other components are attached. This panel will need to be removed also. Once the sliding door motor is accessible, the technician will unplug the motor from the wiring harness, detach the drive cable, and remove the fasteners holding it in place. The new motor is mounted and attached, and all of the surrounding components are restored.. The technician will run the door through a relearning procedure and finish reassembly.

RepairPal recommends that a driver become thoroughly familiar with the operation of a power sliding door to prevent injury to passengers and to avoid a trip to the repair shop for normal functions of the system. There are some normal circumstances that might make a power sliding door motor seem to malfunction. For instance, on some vans, if the fuel door is left open, the sliding door on the same side of the vehicle is disabled so that it will not strike the fuel door. And, if a van with power sliding doors is shifted out of park, the power sliding feature will not work. In this case, an alarm tone is usually heard to signal the driver that a door is still open while the vehicle is moving.

Malfunctions with power sliding doors can lead to injury. Symptoms will generally worsen with time and further damage can result if the problem is left untreated.

Due to the complexity of a power sliding door system, replacement of the door motor on most vans should be left to a qualified technician at a trusted repair shop. This repair can be expensive, but more damage - and cost - can be incurred if the repair is not completed properly.