AutoCodes – Chevrolet – P1004 2014 Chevrolet Silverado

P1004 2014 Chevrolet Silverado Code - NOx Sensor 2 Slow Response

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 2, Nitrogen Oxides Sensor 2 harness is open or shorted, Nitrogen Oxides Sensor 2 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: P1004 2014 Chevrolet Silverado indicates NOx Sensor 2 Slow Response.
Common causes: Common causes include Faulty Nitrogen Oxides (NOx) Sensor 2, Nitrogen Oxides Sensor 2 harness is open or shorted, Nitrogen Oxides Sensor 2 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 194

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 P1004 2014 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 P1004 2014 Chevrolet Silverado - NOx Sensor 2 Slow Response - AutoCodes.com — P1004 2014 Chevrolet Silverado Code - NOx Sensor 2 Slow Response

What does this mean?

What are the Possible Causes of the DTC P1004 2014 Chevrolet Silverado?

Faulty Nitrogen Oxides (NOx) Sensor 2
Nitrogen Oxides Sensor 2 harness is open or shorted
Nitrogen Oxides Sensor 2 circuit poor electrical connection

How to Fix the DTC P1004 2014 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 P1004 2014 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 P1004 2014 Chevrolet Silverado 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 P1004 2014 Chevrolet Silverado Code

1. What does the OBDII code P1004 mean on a 2014 Chevrolet Silverado?

P1004 indicates a "NOx Sensor 2 Slow Response," meaning the NOx sensor located downstream of the catalytic converter is not responding as expected.

2. What are the common symptoms of code P1004 in a 2014 Chevrolet Silverado?

Symptoms may include a check engine light, reduced fuel efficiency, poor engine performance, or the vehicle entering limp mode.

3. What causes the P1004 code in a 2014 Chevrolet Silverado?

Common causes include a faulty NOx sensor, damaged wiring or connectors, excessive soot buildup on the sensor, or issues with the exhaust system.

4. Can I drive my 2014 Chevrolet Silverado with a P1004 code?

Driving with this code is not recommended as it may reduce engine performance, harm fuel efficiency, and potentially damage the catalytic converter if left unresolved.

5. How do I diagnose the P1004 code on my 2014 Chevrolet Silverado?

Start by scanning the vehicle for additional codes, inspecting the NOx sensor and wiring for damage, and testing the sensorâ€™s response using a diagnostic tool.

6. How much does it cost to fix the P1004 code on a 2014 Chevrolet Silverado?

Repair costs vary but typically range from $200 to $600, depending on whether the NOx sensor needs replacement or if there are wiring or exhaust issues.

7. Can a dirty or clogged NOx sensor cause the P1004 code?

Yes, soot buildup or contamination on the NOx sensor can lead to a slow response and trigger the P1004 code.

8. Do I need to replace the NOx sensor to fix code P1004?

Not always. The sensor should be tested first; cleaning or repairing wiring might resolve the issue. If the sensor is faulty, replacement may be necessary.

9. How can I prevent the P1004 code from recurring?

Regular maintenance, using high-quality fuel, and ensuring proper functioning of the exhaust system can help prevent this code from reappearing.

10. Is a software update ever required to fix the P1004 code?

In some cases, a PCM (Powertrain Control Module) update may be needed to address the code if the issue is related to outdated engine management software.