P2121, P2122, P2123, P2125, P2126, P2127, P2128 Throttle/pedal position sensor/switch D, E low/high input, range/performance

Land Rover OBD-II Trouble Codes ------------------------------------------------The diagnostic trouble codes (DTCs) P2121 through P2128 all relate to issues with the Throttle/Pedal Position Sensor/Switch D and E. These codes indicate problems with the low/high input, range, or performance of the throttle/pedal position sensor/switch. Here's a breakdown of each code:

1. **P2121 - Throttle/Pedal Position Sensor/Switch D Circuit Range/Performance:**

   - Indicates a range or performance issue with Throttle/Pedal Position Sensor/Switch D.

2. **P2122 - Throttle/Pedal Position Sensor/Switch D Circuit Low Input:**

   - Suggests a low voltage condition in the Throttle/Pedal Position Sensor/Switch D circuit.

3. **P2123 - Throttle/Pedal Position Sensor/Switch D Circuit High Input:**

   - Indicates a high voltage condition in the Throttle/Pedal Position Sensor/Switch D circuit.

4. **P2125 - Throttle/Pedal Position Sensor/Switch E Circuit Range/Performance:**

   - Indicates a range or performance issue with Throttle/Pedal Position Sensor/Switch E.

5. **P2126 - Throttle/Pedal Position Sensor/Switch E Circuit Low Input:**

   - Suggests a low voltage condition in the Throttle/Pedal Position Sensor/Switch E circuit.

6. **P2127 - Throttle/Pedal Position Sensor/Switch E Circuit High Input:**

   - Indicates a high voltage condition in the Throttle/Pedal Position Sensor/Switch E circuit.

7. **P2128 - Throttle/Pedal Position Sensor/Switch E Circuit F Range/Performance:**

   - Indicates a range or performance issue with Throttle/Pedal Position Sensor/Switch E.

### Possible Causes:

1. **Faulty Throttle/Pedal Position Sensor/Switch D or E:** Issues with the sensors themselves, such as wear, damage, or electrical malfunctions.

2. **Wiring Issues:** Problems with the wiring or connectors associated with the Throttle/Pedal Position Sensor/Switch D or E circuits.

3. **Connector Problems:** Faulty connectors or terminal issues in the wiring harness related to the Throttle/Pedal Position Sensor/Switch D or E.

4. **Electronic Control Module (ECM) Issues:** Problems with the ECM responsible for managing the throttle position sensors.

### Diagnostic Steps:

1. **Inspect Throttle/Pedal Position Sensor/Switch D and E:** Check the sensors for signs of damage or wear. If they appear faulty, consider replacement.

2. **Check Wiring and Connectors:** Inspect the wiring and connectors associated with the Throttle/Pedal Position Sensor/Switch D and E circuits. Look for any signs of damage, corrosion, or loose connections.

3. **Perform Continuity Tests:** Check for continuity in the wiring from the sensors to the ECM.

4. **Verify Voltage Levels:** Use a multimeter to verify the voltage levels in the Throttle/Pedal Position Sensor/Switch D and E circuits.

5. **Verify ECM Operation:** Test the ECM for proper operation and communication with the throttle position sensors.

6. **Clear Codes:** After addressing any identified issues, clear the trouble codes and monitor the system for recurrence.

7. **Consider Professional Assistance:** If you are unsure about diagnosing or addressing these issues yourself, or if the faults persist, it's advisable to consult with a qualified mechanic or technician.

Addressing the root cause of the Throttle/Pedal Position Sensor/Switch D and E faults is crucial for proper engine performance and throttle response. If in doubt or if the faults persist, seeking professional assistance is recommended for a thorough diagnosis and effective repair.