P1129 – OBD-II DTC

OBD-II DTC P1129 – Throttle Position Sensor Out Of Self Test Range

DTC P1129 meaning

DTC P1129 refers to a diagnostic trouble code indicating that the Throttle Position Sensor (TPS) is out of the self-test range. The TPS is a critical component that monitors the position of the throttle plate in the engine. This code suggests that the readings from the TPS are not within the expected parameters during the vehicle’s self-diagnostic tests.

DTC P1129 symptoms

Common symptoms associated with DTC P1129 may include:

• Check Engine Light illuminated
• Unresponsive or erratic throttle response
• Engine stalling or hesitation during acceleration
• Reduced engine power or performance
• Increased fuel consumption

DTC P1129 causes

Several factors can lead to the triggering of DTC P1129, including:

• Faulty Throttle Position Sensor
• Wiring issues or poor connections in the TPS circuit
• Malfunctioning Engine Control Module (ECM)
• Mechanical issues with the throttle body
• Vacuum leaks affecting the air intake

DTC P1129 seriousness

DTC P1129 can be considered serious as it may affect the vehicle’s drivability and performance. If left unaddressed, it can lead to further engine issues, increased emissions, and potential safety hazards due to reduced throttle response.

How to diagnose DTC P1129

To diagnose DTC P1129, follow these steps:

1. Use an OBD-II scanner to confirm the presence of the P1129 code.
2. Inspect the Throttle Position Sensor and its wiring for any visible damage or disconnections.
3. Check the TPS voltage and resistance using a multimeter to ensure it operates within specifications.
4. Examine the throttle body for any mechanical issues, such as sticking or dirt buildup.
5. Perform a visual inspection for vacuum leaks in the intake system.
6. Clear the code and perform a road test to see if the code reappears.

How to fix DTC P1129 step-by-step instructions

To fix DTC P1129, follow these steps:

1. Inspect and repair any damaged wiring or connectors related to the Throttle Position Sensor.
2. If the TPS is faulty, replace it with a new sensor.
3. Clean the throttle body to ensure smooth operation.
4. Check for and repair any vacuum leaks in the intake system.
5. Recheck the TPS voltage and resistance after repairs to confirm proper operation.
6. Clear the DTC using an OBD-II scanner and perform a test drive to ensure the issue is resolved.

How to erase DTC P1129

To erase DTC P1129, follow these steps:

1. Connect an OBD-II scanner to the vehicle’s diagnostic port.
2. Turn on the ignition without starting the engine.
3. Navigate to the “Erase Codes” or “Clear DTCs” option on the scanner.
4. Confirm the action to clear the trouble codes.
5. Disconnect the scanner and start the engine to verify that the code does not reappear.

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