P2122: Throttle/Pedal Position Sensor/Switch "D" Circuit Low

Definition

The OBD2 code P2122 indicates that the Throttle/Pedal Position Sensor/Switch "D" circuit is reading a low voltage, which suggests a potential issue with the sensor or its wiring

Common causes

Faulty throttle position sensor
Damaged wiring or connectors
Poor electrical connections
Faulty accelerator pedal position sensor
Short circuit in the circuit
Open circuit in the circuit
Corroded connectors
Faulty engine control module (ECM)

Common misdiagnoses

Faulty throttle position sensor
Faulty accelerator pedal position sensor
Wiring issues or shorts in the circuit
Faulty engine control module (ECM)
Issues with the electronic throttle control system
Vacuum leaks
Faulty mass air flow sensor
Fuel delivery problems
Ignition system issues
Transmission problems

Troubleshooting steps

1. Check for Additional Codes

Before proceeding, check for any other related trouble codes that may provide more context to the issue
2. Inspect Wiring and Connectors
3. Visually inspect the wiring and connectors associated with the throttle position sensor and pedal position sensor. Look for signs of damage, corrosion, or loose connections
4. Ensure that all connectors are securely attached and free of dirt or moisture
5. Test the Throttle Position Sensor (TPS)
6. Use a multimeter to test the resistance and voltage output of the TPS. Compare the readings to the specifications provided in the vehicle's service manual
7. Check for smooth operation throughout the entire range of motion. Any dead spots or erratic readings may indicate a faulty sensor
8. Check the Accelerator Pedal Position Sensor
9. Similar to the TPS, test the accelerator pedal position sensor for proper voltage and resistance. Ensure it operates smoothly and within the specified range
10. Inspect the Throttle Body
11. Check the throttle body for any obstructions, carbon buildup, or mechanical issues that could affect throttle operation
12. Ensure that the throttle plate moves freely and is not sticking
13. Check for Ground Issues
14. Ensure that the ground connections for the throttle and pedal position sensors are secure and free of corrosion. A poor ground can lead to low voltage readings
15. Scan for Software Updates
16. Check if there are any software updates available for the vehicle's engine control module (ECM). Sometimes, manufacturers release updates to address known issues
17. Clear the Codes and Test Drive
18. After performing the above checks and repairs, clear the trouble codes using an OBD-II scanner and take the vehicle for a test drive to see if the code returns
19. Replace Faulty Components
20. If any of the sensors or wiring are found to be faulty during testing, replace them as necessary
21. Consult a Professional
22. If the issue persists after performing these steps, it may be necessary to consult a professional mechanic or technician for further diagnosis. By following these troubleshooting steps, you should be able to identify and resolve the issue related to the P2122 code

Definition

Common causes

Common misdiagnoses

Troubleshooting steps

1. Check for Additional Codes

2. Inspect Wiring and Connectors

3. Visually inspect the wiring and connectors associated with the throttle position sensor and pedal position sensor. Look for signs of damage, corrosion, or loose connections

4. Ensure that all connectors are securely attached and free of dirt or moisture

5. Test the Throttle Position Sensor (TPS)

6. Use a multimeter to test the resistance and voltage output of the TPS. Compare the readings to the specifications provided in the vehicle's service manual

7. Check for smooth operation throughout the entire range of motion. Any dead spots or erratic readings may indicate a faulty sensor

8. Check the Accelerator Pedal Position Sensor

9. Similar to the TPS, test the accelerator pedal position sensor for proper voltage and resistance. Ensure it operates smoothly and within the specified range

10. Inspect the Throttle Body

11. Check the throttle body for any obstructions, carbon buildup, or mechanical issues that could affect throttle operation

12. Ensure that the throttle plate moves freely and is not sticking

13. Check for Ground Issues

14. Ensure that the ground connections for the throttle and pedal position sensors are secure and free of corrosion. A poor ground can lead to low voltage readings

15. Scan for Software Updates

16. Check if there are any software updates available for the vehicle's engine control module (ECM). Sometimes, manufacturers release updates to address known issues

17. Clear the Codes and Test Drive

18. After performing the above checks and repairs, clear the trouble codes using an OBD-II scanner and take the vehicle for a test drive to see if the code returns

19. Replace Faulty Components

20. If any of the sensors or wiring are found to be faulty during testing, replace them as necessary

21. Consult a Professional

22. If the issue persists after performing these steps, it may be necessary to consult a professional mechanic or technician for further diagnosis. By following these troubleshooting steps, you should be able to identify and resolve the issue related to the P2122 code