AutoCodes – GMC – P2203 2015 GMC Sierra

P2203 2015 GMC Sierra Code - NOx Sensor 1 Circuit High Voltage

Quick Answer

The Nitrogen Oxides (NOx) sensors are part of the selective catalytic reduction system, a device used to reduce NOx emission on diesel engines. Common causes include Faulty Nitrogen Oxides (NOx) Sensor, Nitrogen Oxides Sensor harness is open or shorted, Nitrogen Oxides Sensor 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: P2203 2015 GMC Sierra indicates NOx Sensor 1 Circuit High Voltage.
Common causes: Common causes include Faulty Nitrogen Oxides (NOx) Sensor, Nitrogen Oxides Sensor harness is open or shorted, Nitrogen Oxides Sensor 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 187

How popular is this code, among other codes? Low

Repair Importance Level

Urgent (Diagnose now) (3 / 3)

Repair Difficulty Level

Advanced (Pro) (3 / 3)

What is this?

Table of contents Created and updated by William Orellana on Mar 24, 2024

Description
Possible Causes
How To Fix
Cost to Diagnose
FAQs
Comments
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Code P2203 2015 GMC Sierra Description

The Nitrogen Oxides (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 DTC when a serial data message is received from the NOx sensor module. The Diagnostic Trouble Code (DTC) will be set if the ECM software detects a fault in the NOx sensor circuitry or a performance fault in the NOx sensor for greater than 2 s.

OBDII Code P2203 2015 GMC Sierra - NOx Sensor 1 Circuit High Voltage - AutoCodes.com — P2203 2015 GMC Sierra Code - NOx Sensor 1 Circuit High Voltage

What does this mean?

What are the Possible Causes of the DTC P2203 2015 GMC Sierra?

Faulty Nitrogen Oxides (NOx) Sensor
Nitrogen Oxides Sensor harness is open or shorted
Nitrogen Oxides Sensor circuit poor electrical connection

How to Fix the DTC P2203 2015 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 is the Cost to Diagnose the Code?

Labor: 1.0

To diagnose the P2203 2015 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.

Need more information about the P2203 2015 GMC Sierra code?

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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 P2203 2015 GMC Sierra Code

1. What does the OBDII code P2203 mean for a 2015 GMC Sierra?

P2203 indicates that the NOx Sensor 1 (Nitrogen Oxide Sensor) circuit is experiencing high voltage, which may interfere with its ability to measure NOx levels in the exhaust system accurately.

2. What are the common symptoms of code P2203 on a 2015 GMC Sierra?

Symptoms may include the check engine light turning on, reduced fuel efficiency, increased emissions, and potential loss of engine performance.

3. What causes code P2203 in a 2015 GMC Sierra?

Common causes include a faulty NOx sensor, damaged wiring or connectors in the sensor circuit, excessive soot buildup, or issues with the vehicle's exhaust system.

4. Can I drive my 2015 GMC Sierra with code P2203?

While the vehicle may still be drivable, prolonged operation with this code can lead to increased emissions and potential damage to the exhaust system. Itâ€™s best to address the issue promptly.

5. How do I diagnose code P2203 on my 2015 GMC Sierra?

Diagnosis typically involves inspecting the NOx sensor and its wiring for damage, checking for soot buildup or contamination, and testing the sensorâ€™s voltage output using a multimeter.

6. How do I fix code P2203 on a 2015 GMC Sierra?

Repairs may include replacing the NOx Sensor 1, repairing or replacing damaged wiring or connectors, cleaning the exhaust system, or updating the ECM software if applicable.

7. How much does it cost to repair code P2203 on a 2015 GMC Sierra?

The cost can vary but generally ranges from $300 to $700 for parts and labor, depending on whether a simple wiring fix or full NOx sensor replacement is needed.

8. Can a bad NOx sensor cause other issues in a 2015 GMC Sierra?

Yes, a malfunctioning NOx sensor can lead to increased emissions, reduced fuel efficiency, and possible damage to the catalytic converter over time.

9. How do I prevent code P2203 from occurring on my 2015 GMC Sierra?

Regular maintenance, including cleaning the exhaust system and checking for wiring damage, can help prevent NOx sensor issues.

10. Is code P2203 covered under warranty for a 2015 GMC Sierra?

Coverage depends on the warranty terms, but emissions-related components like NOx sensors may be covered under the vehicleâ€™s emissions warranty. Check with your dealer for details.