P0123 2018 GMC Sierra Code - Throttle Position Sensor Circuit High Voltage
Quick Answer
The P0123 diagnostic trouble code (DTC) for a 2018 GMC Sierra indicates a Throttle Position Sensor Circuit High Voltage. Common causes include Faulty Throttle Position Sensor: The TPS itself may be malfunctioning, sending a high voltage signal to the ECM, Damaged Wiring or Connectors: Corrosion, fraying, or loose connections in the TPS circuit can cause a high voltage reading, ECM Malfunction: A malfunctioning ECM can misinterpret the TPS signal and trigger the P0123 code. Severity is High - diagnose this code as soon as possible. Driving is not recommended if the warning light is flashing, the engine runs poorly, or safety-related symptoms are present.
- What it means
- P0123 2018 GMC Sierra indicates Throttle Position Sensor Circuit High Voltage.
- Common causes
- Common causes include Faulty Throttle Position Sensor: The TPS itself may be malfunctioning, sending a high voltage signal to the ECM, Damaged Wiring or Connectors: Corrosion, fraying, or loose connections in the TPS circuit can cause a high voltage reading, ECM Malfunction: A malfunctioning ECM can misinterpret the TPS signal and trigger the P0123 code.
- Severity
- High - diagnose this code as soon as possible.
- Can I drive?
- Driving is not recommended if the warning light is flashing, the engine runs poorly, or safety-related symptoms are present.
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Code P0123 2018 GMC Sierra Description
The P0123 diagnostic trouble code (DTC) for a 2018 GMC Sierra indicates a Throttle Position Sensor Circuit High Voltage. The throttle position sensor (TPS) is a crucial component of the vehicle's electronic control system, as it monitors the position of the throttle valve and sends this information to the engine control module (ECM). The ECM uses this data to determine the appropriate fuel injection and ignition timing for optimal engine performance.
Common Causes of P0123 2018 GMC Sierra
- Faulty Throttle Position Sensor: The TPS itself may be malfunctioning, sending a high voltage signal to the ECM.
- Damaged Wiring or Connectors: Corrosion, fraying, or loose connections in the TPS circuit can cause a high voltage reading.
- ECM Malfunction: A malfunctioning ECM can misinterpret the TPS signal and trigger the P0123 code.
- Throttle Body Issues: Problems with the throttle body, such as carbon buildup or mechanical issues, can affect the TPS signal.
- Electrical Interference: External factors such as electromagnetic interference can disrupt the TPS circuit and cause a high voltage reading.
Symptoms of P0123 2018 GMC Sierra
- Check Engine Light: The most common symptom associated with the P0123 code is the illumination of the check engine light on the vehicle's dashboard.
- Reduced Power: The vehicle may experience a loss of power or responsiveness when accelerating.
- Rough Idling: The engine may idle roughly or inconsistently, causing vibrations or shaking.
- Poor Fuel Efficiency: The vehicle may consume more fuel than usual due to incorrect fuel delivery caused by the high voltage TPS signal.
- Stalling: In severe cases, the engine may stall while driving or at idle due to the disruption in fuel delivery and ignition timing.
How to Fix P0123 2018 GMC Sierra
- Diagnose the Issue: Use a diagnostic scanner to retrieve the trouble codes and perform a thorough inspection of the TPS, wiring, and connectors.
- Replace the Throttle Position Sensor: If the TPS is faulty, replace it with a new sensor following the manufacturer's guidelines.
- Repair Wiring or Connectors: Repair or replace any damaged wiring or connectors in the TPS circuit to ensure a proper connection.
- Check and Reset ECM: Verify the ECM's functionality and reset it if necessary to clear the P0123 code and recalibrate the TPS signal.
- Test Drive and Monitor: After repairs, test drive the vehicle to ensure the issue is resolved, and monitor for any recurring symptoms or trouble codes.
Cost to Fix P0123 2018 GMC Sierra
The typical repair costs for addressing a Throttle Position Sensor Circuit High Voltage issue can range from $100 to $300, depending on the specific cause of the problem and the cost of parts and labor. It's important to note that diagnosis time and labor rates at auto repair shops can vary significantly, with hourly rates typically ranging between $80 and $150. Factors such as the vehicle's make and model, location, and engine type can also impact the overall repair costs. For a more accurate estimate, it is advisable to consult with local auto repair shops or dealerships.
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