Tech Tips: An Open Door Policy

Repairing the Sliding Door Electric Wiring
These wires must be able to move from the closed position of the door to the open position. And, these wires must be protected to prevent tangling and damage. A flexible, plastic sheath that looks something like a link chain (see Figure 1) keeps all of the wires in order and protected from harm.

Harness Basics
The power sliding door wire harness supplies battery power, ground and various hardwired and data bus signals to the power sliding door components and the rear door control module for various power door functions. There is a wire harness on each side of the vehicle, one for each sliding door. One end of the harness connects at the B-pillar (the door pillar to the left of the driver/to the right of the front seat passenger). The other end of the harness connects to the hinge arm bracket on the bottom of the sliding door. During movement of the sliding door, the harness chain folds and unfolds like links in a chain.

Wire Harness Problems
The wire harness is rather simple and straightforward. The only difference between it and other harnesses is the fact that this harness moves and flexes when the sliding door is operating.

Also, when the sliding door is open, the harness is exposed to the elements, as are the harness connections, which means it’s possible for water, dirt and other debris to enter into the harness. As a result of the folding and unfolding of the harness, the wires bend and flex. And that means that one, or more, of the wires can break.

Earlier models of the minivans (prior to 2009) experienced a higher occurrence of this type of failure than later model versions. Nonetheless, wire breakage can, and does, occur from time to time.

Electrical problems with the sliding door are usually pretty obvious. When the electric window doesn’t operate, or the door won’t open or close, there’s a problem.

Before we take out the harness and check for broken wires, let’s take a look at the bigger picture. Each power sliding door is equipped with a power sliding door assembly with a power sliding door control module (PSDM). The PSDM communicates on the controller area network (CAN) data bus circuit. Therefore, the PSDM can generate and store its own diagnostic trouble codes (DTCs).

The hard-wired circuits for the power sliding door system can be diagnosed using conventional diagnostic tools and procedures. Remember: the most reliable, efficient and accurate means to diagnose the components related to the power sliding door system operation requires the use of a diagnostic scan tool.

Experience has shown that when the windows and door locks don’t work, the problem is often a broken wire. When the door won’t open and close, the cause of the problem might be more complex. Don’t forget that a physical problem with the door might exist; it’s not always an electrical problem. Check the door for proper alignment, worn or binding rollers, or anything that could cause an obstruction to proper operation. If the door can be opened and closed manually, that’s when it’s time to check for DTCs.

There is a series of DTCs that pertain to the operation of the door in the B19A_ and B19B_ sequences. Let’s take a look at one specific code — B19B7 — Left Power Sliding Door Drive Clutch Control Circuit Low. This code will be set when the left power sliding door module senses the left power sliding door clutch driver circuit is less than 1.0 volt while the clutch is engaged. If the door operates manually and the wire harness and its connectors are good, it’s likely the PSDM is bad and must be replaced.

Checking the Wire Harness
A broken wire will not be visible when you look at the harness chain as it is installed in the vehicle. To properly check the harness, it must be removed from the vehicle (the specifics of that task will be covered later).

Inspect the harness connectors, component connectors and all male and female terminals for the following conditions:

  1. Proper connector installation
  2. Damaged connector locks and bent terminals
  3. Corrosion, or other signs of water intrusion
  4. Overheating (a poorly connected terminal is discolored from excessive current draw)

If the harness checks out OK visually, it’s time to check for a broken wire. Disconnect one of the links (the best spot is in the middle of the harness) by bending the chain. Grab each wire one at a time and pull. If the wire is broken, it will be pulled out of the harness (see Figure 2).

Replacing the Power Sliding Door Wire Harness
Replacing the power sliding door wire harness is a rather straightforward task. Begin by disconnecting the negative battery cable. Then, manually open the sliding door. Next, remove (1) the sliding door sill plate, (2) the front door sill plate and (3) the B-pillar trim panel. Using trim stick C-4755, or equivalent, will make the job of removing these panels much easier. Disconnect the power sliding door B-pillar switch electrical connector in order to remove the B-pillar panel.

Disconnect the sliding door wire harness connector from the bottom of the sliding door. Using door trim panel tool C-4829A, remove the wire harness routing clips from the sliding door and the top of the sliding door lower hinge. Pull the locking tab forward to release the rear wire harness chain link clip.

Refer to Figure 3. Disconnect the second row seating side impact sensor electrical connector (5) (this is a small connector with 2 wires). Using door trim panel tool C-4829A, remove the wire harness routing clips (2) and (3). Disconnect the wire harness at the B-pillar (1). Pull the harness (4) out of the body channel.

To install the wire harness, refer to Figure 3. Position the wire harness (4) into the sliding door track cavity. Install the harness routing clips (2) and (3). Connect the sliding door wire harness (1) at the B-pillar. Connect the side impact sensor electrical connector (5).

Position the sliding door wire harness chain link onto the mounting pin on the lower side of the sliding door lower hinge. Push the locking tab rearward to secure the rear harness chain link clip. Next, connect the sliding door wire harness connector at the bottom of the sliding door. To complete the installation, re-install (1) the B-pillar trim panel, (2) the front door sill plate and (3) the sliding door sill plate.