Q: i have an 04 maxima that is shifting hard, especially when the car is driven for a little bit there is a bump every time the gear shift, there is a couple of check engine codes all relating to a bad tps (P1122, P0223, P0123) and somone told me that bad TPS will cause transmission to shift hard, but i find that hard to believe, is this true? i read a couple articles online and from my understanding that if the tps is bad it will have hesitant shifting or it would little shaky like if there was a misfire but i didnt find anything about hard shifting. btw i already change the transmission oil with the specified nissan oil.
A: OK hears what is going on your electronic throttle assembly is malfunctioning it is sending two separate throttle sensors those readings for sensor #1 (p0123 and p0223) that signal is not right. Also P1122 is the code for ETC electronic throttle control? Did some one clean the throttle chamber with car cleaner and remove the gunky carbon? this changed the throttle position the engine has learned and can set a code like that. However after the throttle chamber is replaced or cleaned a IDLE RELEARN must be performed. I would suspect your extended warranty will pick up the price of the throttle chamber and labor for the learning procedure. Use only Nissan certified re manufactured throttle chambers if available. Note only a few technicians know how to reset the idle learn generically. Nissan Uses Consult 2 and Consult 3 scan and computers to preform this procedure. I doubt that the codes your getting will cause hard shift but do get the problem fixed because driving in Fail-Safe 5 degrees throttle opening at 25 to 30 miles an hour is not fun.