AutoCodes – GMC – P2628 GMC

P2628 GMC Code - HO2S Pump Current Trim Circuit High Voltage Sensor 1

Quick Answer

The oxygen content of the exhaust is measured via the Nitrogen Oxide (NOx) sensors. Common causes include Faulty Nitrogen Oxides Sensor 1, Nitrogen Oxides Sensor 1 harness is open or shorted, Nitrogen Oxides Sensor 1 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: P2628 GMC indicates HO2S Pump Current Trim Circuit High Voltage Sensor 1.
Common causes: Common causes include Faulty Nitrogen Oxides Sensor 1, Nitrogen Oxides Sensor 1 harness is open or shorted, Nitrogen Oxides Sensor 1 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 617

How popular is this code, among other codes? Low

Repair Importance Level

Urgent (Diagnose now) (3 / 3)

Repair Difficulty Level

Advanced (Pro) (3 / 3)

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Table of contents Created and updated by William Orellana on Aug 01, 2021

Description
Possible Causes
How To Fix
Cost to Diagnose
FAQs
Comments
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Code P2628 GMC Description

The oxygen content of the exhaust is measured via the Nitrogen Oxide (NOx) sensors. The NOx sensors are part of the selective catalytic reduction system, a device used to reduce NOx emission on diesel engines. There are two NOx sensors, one placed upstream of selective catalytic reduction, to measure inlet NOx concentration, and one placed downstream. They are connected with the control module via CAN and all the information is exchanged through it. Since it is a smart sensor, all the electrical monitoring is performed inside the sensor and only the results are sent to the Engine Control Module (ECM). Each NOx sensor contains a sensing cell, a pumping cell, and a heater. A sample of exhaust gas passes through a diffusion gap between the sensing cell and the pumping cell. The NOx sensor maintains a constant reference voltage across the sensing cell. An electronic circuit within the sensor controls the pump current through the pumping cell in order to maintain a constant voltage in the sensing cell. The amount of current required to maintain the reference voltage in the sensing cell is proportional to the concentration of NOx in the exhaust. The ECM varies the amount of diesel exhaust fluid (reductant) added by varying the reductant injector duty cycle in response to changes in engine exhaust NOx levels. The smart NOx sensors consist of two components, the NOx module and the NOx sensor element that are serviced as a unit. A circuit or performance condition with a NOx sensor is detected by the NOx sensor module. The smart NOx sensor module communicates the condition to the ECM over the serial data line. The ECM sets a Diagnostic Trouble Code (DTC) when a serial data message is received from the NOx sensor module.

OBDII Code P2628 GMC - HO2S Pump Current Trim Circuit High Voltage Sensor 1 - AutoCodes.com — P2628 GMC Code - HO2S Pump Current Trim Circuit High Voltage Sensor 1

What does this mean?

What are the Possible Causes of the DTC P2628 GMC?

Faulty Nitrogen Oxides Sensor 1
Nitrogen Oxides Sensor 1 harness is open or shorted
Nitrogen Oxides Sensor 1 circuit poor electrical connection

How to Fix the DTC P2628 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 is the Cost to Diagnose the Code?

Labor: 1.0

To diagnose the P2628 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.

Need more information about the P2628 GMC code?

Need more information on how to fix the P2628 GMC code? Get Access to Factory Service Manuals

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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 P2628 GMC Code

1. What are the common symptoms of OBDII code P2628 in a GMC vehicle?

The common symptoms of OBDII code P2628 in a GMC vehicle may include poor fuel economy, rough idling, engine hesitation, and the illumination of the Check Engine Light.

2. What does the OBDII code P2628 for HO2S Pump Current Trim Circuit High Voltage Sensor 1 mean in a GMC?

The OBDII code P2628 indicates a high voltage condition in the oxygen sensor pump current trim circuit for Sensor 1 in a GMC vehicle.

3. What are the possible causes of OBDII code P2628 in a GMC?

Possible causes of OBDII code P2628 in a GMC include a faulty oxygen sensor, damaged wiring or connectors in the circuit, a defective oxygen sensor pump, or an issue with the Engine Control Module (ECM).

4. How can I diagnose and repair OBDII code P2628 in my GMC vehicle?

Diagnosing and repairing OBDII code P2628 involves checking the oxygen sensor and its related circuit for any faults, testing the oxygen sensor pump, inspecting the wiring and connectors for damage, and verifying the operation of the ECM.

5. Can I continue driving my GMC with OBDII code P2628 present?

It is not recommended to continue driving your GMC with OBDII code P2628 present, as it can lead to poor engine performance, reduced fuel efficiency, and potential damage to other components over time. It is best to address the issue promptly.

6. How much does it typically cost to repair OBDII code P2628 in a GMC?

The cost to repair OBDII code P2628 in a GMC can vary depending on the specific cause of the issue, the parts needed for repair, and labor costs. It is advisable to consult with a professional mechanic for an accurate estimate.

7. Can a DIY enthusiast fix OBDII code P2628 in a GMC?

While some DIY enthusiasts may have the skills to diagnose and repair OBDII code P2628 in a GMC, it is a complex issue that may require specialized tools and knowledge. It is recommended to seek assistance from a qualified mechanic for proper diagnosis and repair.

8. How urgent is it to address OBDII code P2628 in a GMC?

It is important to address OBDII code P2628 in a GMC promptly to prevent further damage to the vehicle's components and ensure optimal engine performance. Ignoring the issue can lead to more serious problems down the line.

9. Is OBDII code P2628 a common issue in GMC vehicles?

OBDII code P2628 related to the HO2S Pump Current Trim Circuit High Voltage Sensor 1 is not as common as some other codes, but it can still occur in GMC vehicles due to various factors such as sensor wear, electrical issues, or ECM malfunctions.

10. Can resetting the Check Engine Light resolve OBDII code P2628 in a GMC?

Simply resetting the Check Engine Light will not resolve OBDII code P2628 in a GMC. The underlying issue causing the fault code must be diagnosed and repaired to ensure the problem is resolved.