AutoCodes – GMC – P0122 GMC

P0122 GMC Code - Throttle Position Sensor 1 Circuit Low 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: P0122 GMC indicates Throttle Position Sensor 1 Circuit Low 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 20,962

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 P0122 GMC 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 less than 0.32 V for greater than 1 s.

OBDII Code P0122 GMC - Throttle Position Sensor 1 Circuit Low Voltage - AutoCodes.com — P0122 GMC Code - Throttle Position Sensor 1 Circuit Low Voltage

What does this mean?

What are the Possible Causes of the DTC P0122 GMC?

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 P0122 GMC?

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 P0122 GMC 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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Information for Specific GMC Models

P0122 2014 GMC Sierra — Throttle Position Sensor 1 Circuit Low Voltage
P0122 2015 GMC Sierra — Throttle Position Sensor 1 Circuit Low Voltage
P0122 2016 GMC Sierra — Throttle Position Sensor 1 Circuit Low Voltage
P0122 2017 GMC Sierra — Throttle Position Sensor 1 Circuit Low Voltage
P0122 2018 GMC Sierra — Throttle Position Sensor 1 Circuit Low Voltage

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 P0122 GMC Code

1. What are the common symptoms of OBDII code P0122 GMC (Throttle Position Sensor 1 Circuit Low Voltage)?

The common symptoms include reduced engine power, poor acceleration, stalling, and potential difficulty in shifting gears.

2. What are the possible causes of the P0122 GMC code?

The code P0122 can be triggered by a faulty throttle position sensor, damaged wiring or connectors in the sensor circuit, or a problem with the engine control module (ECM).

3. How can I diagnose the cause of the P0122 code?

You can diagnose the issue by checking the throttle position sensor's voltage output using a multimeter, inspecting the sensor wiring for damage, and scanning the ECM for related error codes.

4. Can a dirty throttle body cause the P0122 code?

Yes, a dirty throttle body can disrupt the correct operation of the throttle position sensor, leading to a low voltage reading and triggering the P0122 code.

5. Is it safe to drive with the P0122 code present?

Driving with the P0122 code may not be safe as it can cause unexpected engine behavior and potential issues with acceleration and power delivery. It is recommended to address the issue promptly.

6. How can I repair the P0122 code on my GMC vehicle?

To repair the P0122 code, you may need to replace the throttle position sensor, repair any damaged wiring or connectors, clean the throttle body, or reset the ECM after addressing the underlying issue.

7. Can I reset the P0122 code without fixing the underlying problem?

Resetting the code without addressing the underlying issue will only temporarily clear the error code. The problem will likely resurface, and it is important to diagnose and repair the root cause.

8. Will the P0122 code cause my vehicle to fail an emissions test?

Yes, the P0122 code can cause your vehicle to fail an emissions test due to the malfunction in the throttle position sensor affecting engine performance and emissions output.

9. Can a DIY enthusiast fix the P0122 code issue?

Depending on your level of expertise, you may be able to address the P0122 code by replacing the throttle position sensor or repairing the wiring. However, complex ECM-related issues may require professional diagnosis and repair.

10. How much does it typically cost to repair the P0122 code on a GMC vehicle?

The cost of repairing the P0122 code can vary depending on the specific cause of the issue, but it may range from $100 to $300 for parts and labor, excluding diagnostic fees.