This part covers the actual controls of the actuator system as I seek to build a full out simulator for it.
This section of the article covers the two position sensors. These aren’t straight-up potentiometers but rather hall effect based sensors. They measure the position of both the engagement selector and the gear selection actuators. This information is fed back to the TCU to precisely control position but to also confirm the transmission forks are in the right spots.
These sensors are a failure point in that internal seal on the actuator can fail over time allowing gearbox fluid to seep into the potentiometer housings. Once this happens, they are easily destroyed. Luckily though they are relatively easy to replace (albeit a bit pricey).
To operate the sensors is fairly straight forward. They are powered from a +5VDC supply and output a 0-5VDC signal proportional with the position. Therefore each sensor has three connections, for a total of 6 on the connector (for both sensors).
The image above is a view looking into the connector going to the position sensors themselves.
|Yellow||Pin 2||Selection – Signal (0-5VDC)|
|Red||Pin 3||+5VDC Supply|
|Green||Pin 5||Engagement – Signal (0-5VDC)|
|Blue||Pin 6||+5VDC Supply|
Each position sensor is meant to measure 3 positions, and with this, allow us to measure the actuator in any gear, including neutral.
Although exact alignment can vary (and so the absolute values are different), you can see how the sensors respond to different positions of the actuator.