HeightControl

Custom height controllers are common on "air suspension" (UZZ31) cars, but not on UZZ32.

After market controllers are advertised as being for uzz31/32 but apparently do not work with UZZ32

A custom-built controller is theoretically possible and there are some public examples, albeit without technical details.

http://minkara.car view.co.jp/en/userid/289550/car/281361/1199579/note.aspx

Service manuals suggest the (stock) height control ECU includes connections for:

ECU inputs include:

• 4 x pressure sensors
• 4 x height control sensors

ECU outputs include:

• 5 x suspension control solenoid valves.

Sensors appear to be variable resistors, but according to this site it may not be that simple http://www.jkwebdesign.net/lsocbb/viewtopic.php?t=8551&highlight=&sid=6a0c3ac397c68f7f82e6db09c2bfd123

The inputs and outputs are apparently analogue (voltage) signals rather than eg frequencies or digital data.

Source:

• http://www.planetsoarer.com/UZZ32/activecomputer.pdf

Therefore; intercept the value from the height control sensors, and add / remove a fudge factor This should make the system think the car is at different height and adjust.

Eg if suspension switch is high, increase values at sensor by x

The principle would be the same as manually adjusting the height by using the fine-tuning rod at each corner of the vehicle. Ie confirm what that rod controls (eg a resistor to adjust voltage?) and the emulate / modify that value as input to the ECU,which will then adjust the car height accordingly.

To ensure there is minimal side effect on the system as designed by Toyota, only allow this to work when vehicle is stationery / low speed / height switch is on high? (All those inputs are also provided in the wiring to suspension ECU).

Rear Height control sensors are accessible through plugs in the boot. SSS swaps left to right to aid in troubleshooting. "Take that arm off of the sensor and mover the sensor arm up and down a few times to see if it makes any difference, or even you can unplug that sensor from inside the boot area. I have in the past connected the left sensor to the right leg ect ( via the wires in the boot) to see if the other leg shows the fault, if it does then it is the sensor. if it does not then it is the valve body solenoid." Source: http://www.soarerworld.com/forum/archive/index.php/t-29764.html

Suspension error codes and test procedures: http://www.soarerworld.com/forum/archive/index.php/t-29764.html Looks like some values are in hz rather than V