Following the discussion on monitoring the coolant temperature, I decided to try and build my own.
Watching the ibus messages with NavCoder I noticed a temperature message from the IKE containing outside and coolant temperatures.
This message is being broadcast every 10 secs.
An example:
1/23/2009 9:45:37 PM: 80 06 BF 19 02 63 00 41
Translates to:
1/23/2009 9:45:37 PM: IKE --> GLO : Temperature: Outside 2°C, Coolant 99°C
A possible solution is now pretty straight forward.
Connect to the ibus, decode the temp message and display the coolant temperature.
I decided to build a prototype to prove the concept and worry about a proper printed circuit board later.
Picture of the gauge in the car:
I decided to mount the gauge in the void drivers side cupholder trimpiece.
I am not much of a mechanical genius but after a day of cutting, grinding and sanding I got it done.
Picture of the various parts before assembly:
Picture after assembly:
Now all it needs is a connection to the car.
It requires Ground, 12V (Cigar Lighter), and the I-bus[WRY] somewhere in the centre console.
No need for a separate temperature sensor or electrical connection to the existing gauge.
After switching to position 1 the display shows 888 C to test all segments at full brightness.
After starting the engine the temperature climbs as expected.
And somewhat later
I tried it on the motorway at 80 mph [outside 6 °C] it gets to 96 °C, rising to 99 °C after slowing down then falling back to 96 °C.
As an extra, when the lights are on the brightness of the display is controlled in concert with the instruments dimmer controller.
The display is being blanked when no update is being received within a 15 secs interval like so [ not a very good picture ]
Note:
The standard gauge reaches NORMAL at approx. 75 °C and stays there at my max. temp of 99 °C.
Hopefully this post can contribute to a solution for the dreaded overheating problem.
Hans