Driving the water guage

[muffdan]

So does anyone know anything about how the water guage works? What does the ECU send it to make the needle go up and down?! I need to drive it myself so I have to figure out what it wants in terms of signal to work.

[SteveJ]

There is no feed to the instrument module from the temperature sensor, so it must be being controlled over the CAN-bus

[muffdan]

cheers Steve, do you know what CAN protocol the ECU uses? Basically is it standard or a Toyota proprietry version?

[SteveJ]

Try this as a starting point - http://www.vassfamily.net/ToyotaPrius/CAN/cindex.html#OC.

It's for a Prius, but I suspect a lot of the data stuff is going to be relavent - I can't see Toyota re-inventing it all from the ground up for the '2

[muffdan]

awesome, that's pretty much all the information I'm going to need. Brilliant, cheers Steve.

[roger]

I never could understand why certain gauges and things disappeared into a box on the wiring diagram, I assume that's why.