P0122 - Throttle/Pedal Position Sensor/Switch A Circuit Low Input
Understanding the Meaning of P0122
The P0122 error code indicates that there is an issue with the Throttle/Pedal
Position Sensor/Switch A Circuit. The sensor measures the position of the throttle
or accelerator pedal and sends a voltage signal to the engine control module (ECM).
When the voltage signal is lower than expected, it triggers the P0122 code.
Common Causes of P0122
There are several reasons that could cause the P0122 error code, including:
- Faulty throttle position sensor
- Malfunctioning accelerator pedal position sensor
- Wiring or electrical connector issues
- Problems with the engine control module (ECM)
Steps to Diagnose and Fix P0122
Follow these steps to diagnose and fix the P0122 error code:
1. Scan for Error Codes
Use an OBD-II scanner to retrieve any stored error codes. If there are other
related codes, address them before tackling the P0122 code.
2. Inspect the Throttle Position Sensor
Locate the throttle position sensor and check for visible damage or wear. If
it appears damaged, replace the sensor.
3. Check the Accelerator Pedal Position Sensor
Inspect the accelerator pedal position sensor for any signs of wear or damage.
If the sensor is faulty, replace it.
4. Examine Wiring and Electrical Connectors
Check the wiring and electrical connectors leading to the throttle position sensor
and accelerator pedal position sensor. Look for signs of damage, corrosion, or loose
connections. Repair or replace any damaged components.
5. Test the Throttle Position Sensor
Using a digital multimeter, test the throttle position sensor's voltage output
while slowly opening the throttle. The voltage should increase smoothly. If the
voltage reading is erratic or doesn't change, replace the sensor.
6. Test the Accelerator Pedal Position Sensor
Use a digital multimeter to test the accelerator pedal position sensor's voltage
output while slowly depressing the pedal. The voltage should increase smoothly.
If the voltage reading is erratic or doesn't change, replace the sensor.
7. Check the Engine Control Module
If all other steps have been completed and the issue persists, the engine control
module (ECM) may be at fault. Consult a professional mechanic for further diagnosis
and potential ECM replacement.
8. Clear the Error Code
After fixing the issue, use the OBD-II scanner to clear the P0122 error code.
If the code returns, repeat the diagnostic process to identify any missed issues.