Replacement stereo and MFD

I replaced the stock Matsushita CD/radio the other day with a Sony CDX-GT610Ui. It has an Ipod, AUX and USB connection and sounds great.

HOWEVER......., there is now no info coming from the engine or the air conditioner to the MFD. I can no longer control the A/C from the MFD. The A/C is still controllable from the steering wheel, but not the fine details.

I do not see what roll the stereo had in the engine/MFD or the AC/MFD. Why would this be a problem?

All the connections were correct. Reconnection of the stock stereo returned the system to normal.

Does anyone have a solution, or am I destined to return the new stereo and buy the DICE. Which I am not sure will play AUX or USB devices.

 

Thank you Vagabond. The one think I failed to mention was that there was a plug going into the head unit next to the CD changer 12 pin connector that did not have a place in the new setup. I do not know how to reconcile that plug.

 

Problem solved!!!!!

The 20 pin connector going into the back of the stock stereo is the root of the problem.

There are five wires. Three of which involve stock stereo communication going to the MFD. They are not needed.

The remaining two wires (pink and white) need to be connected so that info continues to go from AC and engine to the MFD.

I, with the assistance of the METRA folks, connected these two wires with a 68 ohm resistor. When re-connected, all A/C and engine functions returned to the MFD.

I now have an aftermarket stereo with ipod, aux and USB connectivity. The car still works.