Accelerator Pedal Position Sensor

The pedal is not replaced. All they do is trim the pedal to give greater clearance with the floor mat.

 

There are two sensors in the same assembly. When they don't closely agree, an error is thrown, but in many cases the ECU can still read the pedal position from one working sensor.

Tom

 

To Helio & firepa63,

I repeat Helio's question about whether the sensor is in the pedal assembly because I thought when they started the pedal recall that you could get the pedal replaced instead of just trimmed if you were really insistent upon it (although Toyota wanted to do the trim job first before thinking about doing a replacement---probably because the number of new pedal assemblies was in short supply at the beginning of the recall & if they could get away with just doing the trim job, they would be ahead of the game). So are the position sensors in the pedal assembly or somewhere else separate from the pedal? And, Helio, just what is it that Autozone sells---a new pedal assembly or just the sensor(s)?

Ken (in Bolton,Ct)

 

If I had to do it over again I would not go with the trimmed pedal. It is a pain! I find my foot slips off it all the time. Just make sure your mat is secured at all times and enjoy the pedal you have. That is my 2 cents worth, anyone else feel the same way? Hal

 

The sensor is in a small separate assembly that looks like a potentiometer. The pedal can be removed and replaced while retaining the original sensor.

Mine was just trimmed. I didn't see a need for it, but it hasn't caused me any trouble.

Tom

 

I thought the accelerator pedal position sensor was in throttle body assembly.

 

The throttle body assembly is where the air enters the engine consisting of the butterfly valve and control motor.

John (Britprius)

 

There should be very little wear on the pedal-position sensor; it handles very little load because it is only providing a signal for the computer. If it fails, it's probably due to a manufacturing defect.

 

Please check out the screenshots of techstream on my car. One is with foot off the gas pedal and another with foot completely depressed. On the left hand side you can see the 2 "Accelerator pedal sensors" and on the right you can see the % pedal depressed which matches with what I am doing, however the 2 accelerator pedal position sensor # 1 and # 2 don't match ever, even with the pedal not depressed # 1 is at 16%. After doing some research I found that these 2 sensors are actually located on the Throttle Body Assembly, so I went ahead and changed it with a used one but these numbers did not change at all, and the issues did not get fixed completely. Did I research incorrectly?

 

It looks like one of them has failed. Due to the redundant design, you're operating on the backup sensor.

 

The throttle position sensors on the gen2 Prius are "hall effect devices" (a transistor that can sense the strength of a magnetic field). Many older cars use a potentiometer. Like all electronic devises they can fail, but they do not ware or suffer from bad contact in the same way that a potentiometer does with a wiper running up and down a resistance track.

John (Britprius)

 

Your problem is more likely to be at the pedal end of the system.

John (Britprius)

 

Aha! Will replace it and then check it again. Hopefully this eradicates the problem.

 

When I step on the gas pedal, I hear a "click" almost every time. Is this related to the sensor issue?

 

Hold on, P1121 is not for the accelerator position sensor on Toyotas. P1121 on a Prius is a problem with the coolant flow control valve.
Luscious Garage | Blog | Prius P1121: Coolant Flow Control Valve Position Sensor Stuck

A clicking accelerator pedal is not normal. In this case, the pedal assembly might have a mechanical defect.