Code Reader

I have looked all over the internet and I cannot find the information I'm looking for. Either I don't know what I'm looking at or not searching the right terms.

I have a small diesel fired heater in my pickup that heats the engine coolant. With the hot coolant I also run a fan on a heater core and water pump that circulates coolant for another purpose. However if the diesel heater faults out it shuts down like it should but the fan and pump keep running.

Want I want to do is when the heater faults it also tells the fan and pump to stop running. The diagnostic line is a K line running ISO9141.

I have all the needed information from the manufacturer for the fault codes and corresponding hex decimal code, I know the baud rate etc. I have the hardware figured out between the heater and arduino. But thats where it all stops. I don't know what I need to do to get that data through the interface to the arduino and then how or what to write for code to decipher the data.

Could someone please head me in the right direction?

Thanks Greg

Start here:

http://sourceforge.net/projects/obdcon/

Having you considered wiring the pump and fan through a thermostatic switch, so they only come on when the heater is hot?

PeterH: Having you considered wiring the pump and fan through a thermostatic switch, so they only come on when the heater is hot?

Ya I know I could do that. But It would not be as much fun and I really wouldn't learn anything new. Not only that I could have fault code read out of the problem as well. Could also control other things in the vehicle.

Greg