Hi,
I am trying to modify the Sat/Nav (DVD) sytem in my GS 430 to enable me to input destinations whilst moving. This is so my son can do this whilst I am driving, so I can keep my eyes on the road and all that.
I had heard that others had done this, but with no real detail on how to do it. So Chris (Sporties son) and I set about the task yesterday. Our first problem was identifying the speed input to the Nav ECU. This was fun, picture this:- boot open, Chris lying in boot with a multi meter measuring the voltages going into the ECU in the boot. All this whilst I drove the car up and down the close, shouting instructions through the window to him.
He was a good lad telling me what the meter said, but it's not the same as seeing it myself. So plan "B" jack the rear of the car up with one wheel of the ground. Lots of blocks under wheels to stop the car moving. Selecting drive, letting one rear wheel revolve whilst lying in the boot measuring the inputs to the ECU. Yessss found the input!!!!!!!!!!!.
So we then installed an electronic timer (Maplin IC 555 kit) into the speed senser wire input to the ECU and off down the road to test it out.
We start the timer which disconnects the speed senser from the Nav ECU (computer) for a preset time (initialy set to approx 2mts) and so the computer thinks the car has stopped and this enables you to enter the destination whilst driving. However the computer must be quite clever as after approx 22 seconds the buttons grey out and the satellites take over the navigation. Even though there is no input from the wheel speed sensers.
We then have to wait 10 seconds before reactivating the timer, which then gives us another 22 seconds to finish the inputting before the computer takes over etc etc.
So the problem now is how to make the time longer before the ECU works out that there is no input from the wheel speed sensers and get the satellites to take over?
One thought is to disconnect the GPS aerial at the same time as the speed senser, so that the system has no idea were it is until the input is finished and then we reconnecting both?
But I would prefer not to cut the aerial wire unless we have to as i want it to be easy to install and remove.
I would be grateful of any help or ideas you may have in solving this problem?
Once solved, easy step by step instructions will be posted for others to benefit.
Sportie. :D