5 SYMPTOMS OF A BAD ACCELERATOR PEDAL POSITION SENSOR
purpose
The purpose of the accelerator pedal position sensor is to measure the position of the pedal as it’s being pressed down. This information is then used by the ECM (engine control module) to command the electronic throttle body to open up and allow air to come in. This is known as a drive-by-wire system, which most modern cars have. If you have an older car, you’ll most likely have a drive-by cable system. (video below of 2000 Toyota Camry).
location
The accelerator pedal position sensor can be found on the gas pedal
Symptoms
engine light
The first symptom of a bad accelerator pedal position sensor is having a check engine light on. Here are some trouble codes that may show up:
P0120
P0121
P0122
P0123
P0124
P0220
P0221
P0222
P0223
P0224
P0225
P0226
P0227
P0228
P0229
P2121
P2122
P2123
P2124
P2125
P2126
P2127
P2128
P2130
P2131
P2132
P2133
P2134
P2135
P2136
P2137
P2138
P2139
Ensure you can access your car's diagnostic codes by acquiring an OBD2 scanner here.
Car hesitates to move
The second symptom is your car hesitating to move. You’ll be pressing down on the pedal but your car only moves seconds after. This happens due to the accelerator sensor not being able to detect the exact position of the gas pedal.
poor acceleration
The third symptom of a bad accelerator pedal position sensor is poor acceleration. You won’t be able to accelerate as fast as usual because the pedal position sensor isn’t communicating to the ECM (engine control module) to make the proper commands to open up the throttle plate.
limp mode
The fourth symptom you might be experiencing is your car going into limp mode. Limp mode is a safety feature that protects you and your car. Your car will be a lot slower, the RPMs and speed will be limited, and you’ll usually be stuck in second/third gear. Your safety could be at risk if the accelerator pedal position sensor fails because it’s responsible for communicating data to the ECM (engine control module) to open or close the throttle plate while driving. That’s why limp mode gets activated in your vehicle.
unresponsive gas pedal
The fifth symptom you could be experiencing is not getting a response when pressing down on the gas pedal. This happens when the accelerator pedal position sensor completely gives out. There have been instances where drivers are on the road and the accelerator stops reacting, so they are forced to pull over. This is why it’s super important to fix the problem right away before letting it build up and get to that point.
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