P2105, P2106, P2111, P2112 Throttle actuator control system - forced engine shutdown/ limited power; stuck open/closed

Land Rover OBD-II Trouble Codes -------------------------------------------------The diagnostic trouble codes (DTCs) P2105, P2106, P2111, and P2112 all relate to issues with the Throttle Actuator Control (TAC) system, indicating problems with the throttle actuator. Here's a breakdown of each code:

1. **P2105 - Throttle Actuator Control System - Forced Engine Shutdown:**

   - This code indicates that the Throttle Actuator Control (TAC) system has forced an engine shutdown.

2. **P2106 - Throttle Actuator Control System - Forced Limited Power:**

   - P2106 suggests that the TAC system has forced the engine into a limited power mode.

3. **P2111 - Throttle Actuator Control System - Stuck Open:**

   - Indicates that the TAC system has detected a problem where the throttle actuator is stuck in the open position.

4. **P2112 - Throttle Actuator Control System - Stuck Closed:**

   - P2112 points to a situation where the TAC system has identified a problem with the throttle actuator being stuck in the closed position.

### Possible Causes:

1. **Faulty Throttle Actuator Control Motor:** Issues with the motor responsible for controlling the throttle.

2. **Wiring Issues:** Problems with the wiring or connectors associated with the Throttle Actuator Control system.

3. **Throttle Position Sensor Issues:** Malfunctioning throttle position sensor affecting the TAC system.

4. **Faulty Throttle Body:** Problems within the throttle body itself that impact TAC system operation.

5. **Connector Problems:** Faulty connectors or terminal issues in the wiring harness related to the TAC system.

6. **Mechanical Obstruction:** Physical obstructions or issues within the throttle body preventing proper movement.

7. **Electronic Control Module (ECM) Issues:** Problems with the ECM responsible for managing the TAC system.

### Diagnostic Steps:

1. **Inspect Throttle Actuator Control Motor:** Check the Throttle Actuator Control motor for signs of damage or wear. If it appears faulty, consider replacement.

2. **Check Wiring and Connectors:** Inspect the wiring and connectors associated with the Throttle Actuator Control system. Look for any signs of damage, corrosion, or loose connections.

3. **Test Throttle Position Sensor:** Check the throttle position sensor for proper operation. Replace if necessary.

4. **Verify Throttle Body Functionality:** Ensure that the throttle body is mechanically sound and functioning correctly.

5. **Perform Continuity Tests:** Check for continuity in the wiring from the Throttle Actuator Control motor to the ECM.

6. **Check for Short or Open Circuits:** Look for short circuits or open circuits in the Throttle Actuator Control system wiring.

7. **Verify Throttle Body Movement:** Ensure that the throttle body can move freely and is not mechanically obstructed.

8. **Verify ECM Operation:** Test the ECM for proper operation. Replace if necessary.

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

10. **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.

These codes indicate critical issues with the Throttle Actuator Control system, potentially leading to forced engine shutdown or limited power. Addressing the root cause is crucial for proper engine performance and safety. If in doubt or if the faults persist, seeking professional assistance is recommended for a thorough diagnosis and effective repair.