My 03 Maxima has been going into limp home mode for a few months now, without throwing a visible check engine light. It has Evap codes (P0445 and P1448) and a P0650 for the check engine light circuit. When I clear the codes, almost instantly, the P0650 comes back.

Based upon what I have found online, any codes along with a P0650 will throw it into limp home mode because it thinks it has no other way of notifying the driver. That being said, when I turn the key into position 2, the check engine (service engine soon) light does not illuminate, as well as when an actual fault is stored in the ecu. I am assuming that the light is burnt out. Would a blown check engine light bulb cause a P0650? Thanks

 

Unless Nissan made a change in the 2003 model, a burned out/missing light bulb won't cause the P0650. Ask all the people that have bought a car from some unscrupulous person.

See page 442 is section EC of the Nissan FSM for more info.

link to section EC - http://boredmder.com/FSMs/Nissan/Maxima/