What is the P2121 fault number? What is the description of the Throttle/Accelerator Position Sensor/Switch “D” Circuit Range/Performance error code? How can I fix P2121 fault code What are the symptoms of P2121 fault code? …..
What is the P2121 fault code? What does it signify?
The general malfunction code P2121 can be described as “Throttle/Accelerator Pedal Position Sensor/Switch “D” Circuit Range/Performance Malfunction” This setting is for OBD-II-equipped vehicles. Triggers when the powertrain controller module (PCM), detects the throttle opening is not compatible with the current operating conditions.
This code is only valid when electronic controlled (ECTS), applications do not use cables between throttle and accelerator pedal. They also do not have any physical connections. The label “D” in the definition refers specifically to a sensor, switch, circuit or control unit in the throttle control system. The application techniques and components may differ from manufacturer to manufacturer. It is therefore recommended that you refer to your vehicle’s manual for the location of the component designated as “D”.
To control throttle opening, drive-by-wire throttle control systems have at least two position sensors. Some systems may have three. The sensor is attached to an accelerator pedal. Its internal resistance changes as the pedal is pressed, released, or pressed again. These sudden resistance changes result in the voltage signal being sent to the PCM changing. The PCM calculates how hard the accelerator pedal is pressed and controls the throttle motor to ensure that it opens at the right rate. The throttle position sensor (TPS) is also a potentiometer. It measures the throttle opening. The voltage of this sensor increases as the butterfly opens. The rule of thumb is to have a voltage of 0.5 volts when the butterfly opens, and 4.5 volts when it is fully throttled. The PCM provides a ground wire to both sensors and they are also supplied with a reference of 5 volts. If the PCM detects that the throttle opening doesn’t match the current engine speed or the voltage signal is out of range, then a malfunction code P2121 is issued.
P2121 fault codes can be applied to vehicles made by Toyota, Dodge, Lexus and Lexus.
What is the P2121 Fault Code and Why Does It Happen?
Here are some reasons why P2121 should be set.
- – Defective throttle positioning sensor
- – Defective accelerator pedal position sensor
- Sensor for misaligned accelerator pedal position
- – Damaged wires or loose connectors, open, or short circuit issues
- – Grounding problems and power cables
- – A defective electronic throttle control motor
- – A PCM is not working properly or has to be reprogrammed
What are the symptoms for P2121 Fault Code (Symptoms)?
You may experience the following symptoms if you own a vehicle that has the code P2121.
- – Illumination at the check engine lights
- – Variations in engine speed at idle
- Engine stalling
- – Reduced engine performance
- – Stumbling / hesitating during acceleration
- – If the accelerator pedal is pressed, the vehicle might not respond.
- – Exhaust fumes emitting black smoke
- – The engine might not start at all
- – PCM may enter failsafe mode to limit engine power
How to Fix the P2121 Fault Code
The following are some of the possible repairs that could resolve the P2121 fault codes:
- – Repair or replacement wiring harness, connectors, short or open circuit to throttle position sensor, accelerator pedal position sensor, or other sensor
- – Replacing a defective throttle position sensor
- – Replacing an faulty position sensor for the accelerator pedal
- Replacing a damaged throttle motor
- – If the sensor for the accelerator pedal position has been replaced, realign it
- – Reprogramming and replacing the PCM
How serious is the P2121 Fault Code Code?
Fault code P2121 is not likely to prevent the vehicle being driven in most cases. Rarely, however, the vehicle might not respond to pressing the accelerator pedal. You should not drive the vehicle if you are concerned about the accelerator pedal.
