Nissan Repair: Throttle Control Motor Relay open P1126, volt ohm meter, haynes manual

Question
I have a 01 Maxima with 115K miles. Over the past few weeks I noticed that the radio would change stations by itself. The other day the Service Engine light came on. I also noticed that the when I was sitting at a traffic light, the warm air from the heater would start to get cold and the engine temperature needle would fluctuate (this made me think it was the thermostat). I got a quick diagnostic done referencing the code in the subject line. The diagnostic mentioned (1) open or short circuit condition (2) throttle control motor relay circuit open or (3) failed relay. In your expert opinion what has gone bad and needs replacement?

Answer
Will,

First I would have the battery checked to make sure it is not going out.  Strange electrical things are a good give away to a problem.  The throttle control motor relay is the usual suspect on the issue you have.  That is, the relay usually fails first and it is much cheaper than the throttle control motor.  I would change the relay first.  Also, if you get a Haynes Manual you can diagnose the throttle control motor with a volt/ohm meter and that values given in the Haynes Manual.  The book is $20 bucks as is a cheap digital volt/ohm meter.