AutoCodes – Chevrolet – P2203 2018 Chevrolet Silverado

P2203 2018 Chevrolet Silverado 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 2018 Chevrolet Silverado 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 249

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 Mar 24, 2024

Description
Possible Causes
How To Fix
Cost to Diagnose
FAQs
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Code P2203 2018 Chevrolet Silverado 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 2018 Chevrolet Silverado - NOx Sensor 1 Circuit High Voltage - AutoCodes.com — P2203 2018 Chevrolet Silverado Code - NOx Sensor 1 Circuit High Voltage

What does this mean?

What are the Possible Causes of the DTC P2203 2018 Chevrolet Silverado?

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 2018 Chevrolet Silverado?

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 2018 Chevrolet Silverado 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 2018 Chevrolet Silverado code?

Need more information on how to fix the P2203 2018 Chevrolet Silverado 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 P2203 2018 Chevrolet Silverado Code

What does the OBDII code P2203 mean for a 2018 Chevrolet Silverado?

Code P2203 indicates that the NOx Sensor 1 (responsible for monitoring nitrogen oxide levels in the exhaust) has a high voltage issue, suggesting a malfunction in the sensor or its circuit.

What are the common symptoms of code P2203 on a 2018 Chevrolet Silverado?

Symptoms may include the check engine light turning on, reduced fuel efficiency, possible limp mode activation, and increased emissions.

What causes the P2203 code to appear in a 2018 Chevrolet Silverado?

Common causes include a faulty NOx sensor, damaged sensor wiring, poor electrical connections, or issues with the engine control module (ECM).

Can I drive my 2018 Chevrolet Silverado with the P2203 code active?

While the truck may still be drivable, it is not recommended to ignore this code, as it could lead to increased emissions, reduced performance, and potential damage to the exhaust system.

How do I diagnose the P2203 code in my 2018 Chevrolet Silverado?

Diagnosis typically involves scanning for additional codes, visually inspecting the NOx sensor and wiring, testing the sensorâ€™s voltage output, and checking for potential ECM issues.

How much does it cost to repair the P2203 code on a 2018 Chevrolet Silverado?

The cost depends on the exact issue, but replacing a NOx sensor typically ranges from $300 to $700, including parts and labor.

Can a dirty or clogged exhaust system cause the P2203 code?

While uncommon, excessive soot buildup or other exhaust issues could potentially impact the NOx sensor's readings and contribute to this code.

Is it possible to fix the P2203 code without replacing the NOx sensor?

Yes, if the issue is related to damaged wiring or poor connections, repairing those components may resolve the problem without sensor replacement.

How do I reset the P2203 code after repairs on a 2018 Chevrolet Silverado?

After repairs, you can use an OBDII scanner to clear the code. If the issue is resolved, the code should not return.

What maintenance can prevent the P2203 code in a 2018 Chevrolet Silverado?

Regularly inspecting the exhaust system, keeping the engine in good condition, and addressing any check engine light promptly can help prevent this code.