AutoCodes – GMC – P0123 2016 GMC Sierra

P0123 2016 GMC Sierra Code - Throttle Position Sensor Circuit High Voltage

Quick Answer

The Throttle Body Assembly contains a contact-less inductive throttle position sensing element that is managed by a customized integrated circuit. Common causes include Faulty Throttle Body Assembly, Throttle Body Assembly harness is open or shorted, Throttle Body Assembly circuit poor electrical connection. 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 2016 GMC Sierra indicates Throttle Position Sensor Circuit High Voltage.
Common causes: Common causes include Faulty Throttle Body Assembly, Throttle Body Assembly harness is open or shorted, Throttle Body Assembly circuit poor electrical connection.
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 Popularity 200

How popular is this code, among other codes? Low

Repair Importance Level

Urgent (Diagnose now) (3 / 3)

Repair Difficulty Level

Intermediate (2 / 3)

What is this?

Table of contents Created and updated by William Orellana on May 20, 2022

Description
Step-by-Step Diagnostic Guide
Possible Causes
How To Fix
Tech Notes ▶
Cost to Diagnose
FAQs
Comments
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Code P0123 2016 GMC Sierra Description

The Throttle Body Assembly contains a contact-less inductive throttle position sensing element that is managed by a customized integrated circuit. The throttle position sensor is mounted within the throttle body assembly and is not serviceable. The Engine Control Module (ECM) supplies the throttle body with a 5 V reference circuit, a low reference circuit. The asynchronous signal means communication is only going from the throttle body to the ECM. The throttle body cannot receive data from the ECM over the signal/serial data circuit. The throttle position sensor provides a signal voltage that changes relative to throttle blade angle. The throttle position sensor information is transmitted between the throttle body and the ECM on the signal/serial data circuit. The ECM decodes the serial data signal and is used as voltages for throttle position sensor 1 and 2. The Diagnostic Trouble Code (DTC) will be set when the ECM detects the throttle position sensor 1 signal voltage is greater than 4.7 V for greater than 1 s.

OBDII Code P0123 2016 GMC Sierra - Throttle Position Sensor Circuit High Voltage - AutoCodes.com — P0123 2016 GMC Sierra Code - Throttle Position Sensor Circuit High Voltage

What does this mean?

What are the Possible Causes of the DTC P0123 2016 GMC Sierra?

Faulty Throttle Body Assembly
Throttle Body Assembly harness is open or shorted
Throttle Body Assembly circuit poor electrical connection
Faulty Engine Control Module (ECM)

How to Fix the DTC P0123 2016 GMC Sierra?

Review the 'Possible Causes' above and visually examine the corresponding wiring harness and connectors. Check for damaged components and inspect connector pins for signs of being broken, bent, pushed out, or corroded.

What does this mean?

Code Tech Notes

User Submitted Video

What is the Cost to Diagnose the Code?

Labor: 1.0

To diagnose the P0123 2016 GMC Sierra code, it typically requires 1.0 hour of labor. Rates vary by location, vehicle, and shop. Many shops charge between $80–$150 per hour; dealerships and metro areas may be higher, independents may be lower.

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About the author: William Orellana is a Master Mechanic and Mechanical Engineer with over 30 years of experience diagnosing and repairing vehicles. Learn more about his background.

Frequently Asked Questions about P0123 2016 GMC Sierra Code

1. What does the OBDII code P0123 mean on a 2016 GMC Sierra?

P0123 indicates that the throttle position sensor (TPS) circuit has detected a high voltage input, which is outside the expected range.

2. What are the common symptoms of P0123 in a 2016 GMC Sierra?

Symptoms include poor acceleration, rough idling, reduced engine performance, an illuminated check engine light, and possible activation of "limp mode."

3. What causes the P0123 code on a 2016 GMC Sierra?

Common causes include a faulty throttle position sensor, damaged wiring or connectors, corroded electrical connections, or a malfunctioning engine control module (ECM).

4. Can I drive my 2016 GMC Sierra with the P0123 code?

Itâ€™s not recommended to drive with this code for an extended period, as it can lead to poor engine performance, safety issues, and potential damage to other components.

5. How do I diagnose the P0123 code on my 2016 GMC Sierra?

Check the TPS and its wiring for damage or corrosion, test the sensor with a multimeter, and use a scan tool to monitor live TPS data for irregularities.

6. How do I fix the P0123 code on a 2016 GMC Sierra?

Repairs may include replacing the throttle position sensor, repairing or replacing damaged wiring, cleaning corroded connectors, or reprogramming the ECM if needed.

7. How much does it cost to repair the P0123 code on a 2016 GMC Sierra?

The repair cost varies but typically ranges from $100 to $300, depending on whether the TPS, wiring, or connectors need replacement.

8. Can a dirty throttle body cause the P0123 code in a 2016 GMC Sierra?

A dirty throttle body usually causes different codes, but excessive carbon buildup could potentially interfere with the TPS operation.

9. Do I need to reset the ECM after fixing the P0123 code on my 2016 GMC Sierra?

Yes, after repairs, clear the code with an OBDII scan tool and test-drive the vehicle to ensure the issue is resolved.

10. Can a low battery cause the P0123 code on a 2016 GMC Sierra?

A weak or failing battery is unlikely to cause this specific code but can lead to other electrical issues that might indirectly affect the TPS circuit.