The Elusive Power Sliding Door Mechanism

Update 5 April 2010: Question answered!

From day one since I put my interest on Honda Freed I searched high and low for a mechanical rundown for its power sliding door. It’s an important thing for me because I live in a place where 10 cm standing water is a common sight on the streets. On rainy season that amount of water can reach 30 cm deep even. So it’s important for me to know the working of the power sliding door to take any precautionary measure when going through a flooded street.

I waited for Freed to go international outside of Japan before asking around and even now almost 2 years later I still didn’t get a definitive explanation about how a power sliding door works. So I decided to take matter personally and wrestle around the internet and found some patents describing how a power sliding door works.

Power sliding doors are surprisingly complex. Based on two patents that I found regarding power sliding door mechanism, they all work on a system of pulleys and cables. Here’s a quote from Magna as an assignee on its sliding door mechanism patent:

Power operation of the sliding door between the open and closed positions has become a popular feature. Cables are commonly employed to pull the door open and closed due to a required long and curve-linear travel path of the door. Cables are driven by spooling drums of large size to store the required cable lengths. It would be desirable to employ a compact linear drive mechanism to operate a sliding door using cables but without cable drums to reduce size, weight, and complexity.

And here’s another power sliding door patent from Hi-Lex Corporation as an assignee:

According to the invention, an electric motor assembly is mounted on the door and includes a drum driven by the motor, and a cable system driven by the drum includes cable runs adapted to be anchored to spaced points on the body structure. The cable system is operative in response to energization of the motor to move the door assembly between open and closed positions.

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Seeing that these patents refer to a pulley system, it’s not too out there to suspect that Honda employs a similar system. However, no information regarding where the motor or the mechanism is located on the car. If a cable system is used then the answer would be that the mechanism is situated smack dead in the middle of the guide rail, which is very preferable for me. That means if I wade through high standing water, I won’t have to worry about the sliding door mechanism got submerged and damaged. However, upon closer inspection, every time I open Freed’s power sliding door, I can hear an electric motor spinning from the bottom of the car. If the sliding door mechanism is situated around the floor of the car… Then it’s going to be a problem for me.

Finally, I’ve conclude that Freed’s sliding door mechanism is indeed using a cable and pulley system. I’ve always look below the sliding door tracks and never pay attention to the sliding door rail. The thing is, logic told me that the most complex system will be its major moving force. So the bottom side of the sliding door has the most complex mechanism visually. However, it turns out that it’s just a swiveling door hinge and power window conduit cable. So much for careful observation… The cable system that pulls the power sliding door can be seen clearly when the door is fully opened.

Such a small thing to pull the weight of the door

For those having concern about the power sliding door system failing, whereby you can’t open the door… Fear not, as the Freed power sliding door system can be deactivated, making it basically a regular sliding door. The downside of having the system turned off however is the added weight of the system when opened/closed manually. Opening/sliding the doors with the system turned off yield a much heavier door compared to non power sliding door trim. Given, because now you have the added resistance of the motors and the pulley system.

With its power sliding door system and anti-pinch safety measure, Freed’s power sliding door system alone is already a big selling factor. Hope you enjoy yours.