P2123 2018 GMC Sierra Code - Accelerator Pedal Position Sensor 1 Circuit High Voltage
Quick Answer
The diagnostic trouble code P2123 for a 2018 GMC Sierra indicates a problem with the Accelerator Pedal Position Sensor 1 Circuit High Voltage. Common causes include Faulty Accelerator Pedal Position Sensor, Wiring or connector issues in the sensor circuit, Corrosion or damage to sensor connections. 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
- P2123 2018 GMC Sierra indicates Accelerator Pedal Position Sensor 1 Circuit High Voltage.
- Common causes
- Common causes include Faulty Accelerator Pedal Position Sensor, Wiring or connector issues in the sensor circuit, Corrosion or damage to sensor connections.
- 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 P2123 2018 GMC Sierra Description
The diagnostic trouble code P2123 for a 2018 GMC Sierra indicates a problem with the Accelerator Pedal Position Sensor 1 Circuit High Voltage. This sensor is responsible for communicating the position of the accelerator pedal to the engine control module (ECM), allowing the vehicle's computer to adjust fuel and air mixture for optimal performance. When the sensor detects a high voltage signal that is outside the expected range, it triggers the P2123 code, indicating a potential issue with the sensor or its circuit.
Common Causes of P2123 2018 GMC Sierra
- Faulty Accelerator Pedal Position Sensor.
- Wiring or connector issues in the sensor circuit.
- Corrosion or damage to sensor connections.
- ECM software or hardware issues.
- Electrical problems such as short circuits or voltage spikes.
Symptoms of P2123 2018 GMC Sierra
- Engine hesitation or lack of response when pressing the accelerator pedal.
- Surging or jerking during acceleration.
- Decreased fuel efficiency.
- Check Engine Light illuminated on the dashboard.
- Vehicle may go into limp mode, limiting performance.
How to Fix P2123 2018 GMC Sierra
- Begin by diagnosing the root cause of the P2123 code by using a scan tool to check for any additional trouble codes and performing a thorough inspection of the accelerator pedal position sensor and its wiring.
- If the sensor is found to be faulty, replace it with a new one following the manufacturer's guidelines.
- Inspect the wiring and connectors for any signs of damage or corrosion, repairing or replacing as necessary.
- Clear the trouble codes from the ECM and test drive the vehicle to verify that the issue has been resolved.
- If the problem persists, further diagnosis may be required to pinpoint the exact cause of the high voltage signal.
Cost to Fix P2123 2018 GMC Sierra
The cost of repairing the Accelerator Pedal Position Sensor 1 Circuit High Voltage issue can vary depending on the specific cause of the problem and the cost of parts and labor. In general, replacing the sensor itself can range from $100 to $300, while additional costs for wiring repairs or diagnostic time may increase the total cost. Labor rates at auto repair shops can vary, but typically range from $80 to $150 per hour. It's recommended to consult a professional mechanic for a more accurate estimate based on your vehicle's make and model.
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Frequently Asked Questions about P2123 2018 GMC Sierra Code
What does OBDII code P2123 mean on a 2018 GMC Sierra?
P2123 indicates that the vehicle's Engine Control Module (ECM) has detected a high voltage signal from the Accelerator Pedal Position (APP) Sensor 1 circuit, suggesting a potential issue with the sensor or wiring.
What are the symptoms of code P2123 in a 2018 GMC Sierra?
Common symptoms include reduced engine performance, delayed throttle response, activation of "limp mode," and possible illumination of the check engine light.
What causes code P2123 in a 2018 GMC Sierra?
Causes may include a faulty APP sensor, damaged wiring or connectors in the APP circuit, short circuits, or issues with the ECM.
Can I drive my 2018 GMC Sierra with code P2123?
It is not recommended to drive the vehicle with this code active, as throttle control may be compromised, potentially leading to reduced drivability or unsafe conditions.
How is code P2123 diagnosed on a 2018 GMC Sierra?
A technician will inspect the APP sensor, wiring, and connectors for damage, perform voltage and resistance tests, and possibly use a scan tool to monitor sensor data and ECM functionality.
How do you fix code P2123 on a 2018 GMC Sierra?
Repairs may include replacing the APP sensor, repairing or replacing damaged wiring or connectors, or reprogramming or replacing the ECM if needed.
Can a dirty accelerator pedal cause code P2123?
No, a dirty accelerator pedal typically does not cause this code, as it is related to electrical signals rather than mechanical issues.
How much does it cost to repair code P2123 on a 2018 GMC Sierra?
Repair costs can vary, but replacing the APP sensor typically costs $100-$300, while wiring repairs or ECM replacements may increase costs significantly.
Does code P2123 require ECM reprogramming?
In some cases, ECM reprogramming or replacement may be necessary if the issue originates from the ECM itself or if sensor calibration is required.
Can a faulty APP sensor damage the engine on a 2018 GMC Sierra?
A faulty APP sensor is unlikely to cause direct engine damage but can lead to drivability issues that might strain other components if left unaddressed.
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