Would a bad throttle position sensor cause hard shifting in an 04 maxima

Question

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.

Answer 1

A bad TPS shouldn't effect shifting, at least not directly. With a fuel injection engine, the TPS tells the computer how far you have pressed the fuel pedal. The computer in turn adjusts the amount of fuel based on engine speed, whether it's accelerating or decelerating, fuel mixture, and throttle position. Typically a TPS develops "dead" spots in it's range of travel. Pressing the accelerator pedal just right (or wrong) can cause the engine to stall. It most often occurs near the closed end. You will experience a hesitation or stalling when starting off from the stop.

I don't know the specifics of that vehicle. If it is using the TPS as a determining factor as to when to shift, and the sensor is dirty, it might effect shifting. But still it should only effect when and how it shifts. Shifting would not become more rough, unless it is trying to shift in and out of gears rapidly.

Describe the "bump". That might help. You could have a loose motor mount.

Answer 2

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.

Answer 3

This is absolutely true.

Your car shifts depending on where your engine speed is and where your throttle is.  If the computer has to guess what your foot is doing because the sensor is bad, it will shift hard. Especially if it gets or loses the signal voltage suddenly.