AutoCodes – GMC – P2202 GMC

P2202 GMC Code - NOx Sensor 1 Circuit Low 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 Moderate - service should be scheduled soon. The vehicle may still be drivable for short trips if it runs normally, but avoid hard driving and repair it soon.

What it means: P2202 GMC indicates NOx Sensor 1 Circuit Low 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: Moderate - service should be scheduled soon.
Can I drive?: The vehicle may still be drivable for short trips if it runs normally, but avoid hard driving and repair it soon.

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Code Popularity 11,848

How popular is this code, among other codes? Low

Repair Importance Level

Moderate (Service soon) (2 / 3)

Repair Difficulty Level

Intermediate (2 / 3)

What is this?

Table of contents Created and updated by William Orellana on Mar 29, 2024

Description
Possible Causes
How To Fix
Tech Notes
Cost to Diagnose
Comments
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Code P2202 GMC 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 P2202 GMC - NOx Sensor 1 Circuit Low Voltage - AutoCodes.com — P2202 GMC Code - NOx Sensor 1 Circuit Low Voltage

What does this mean?

What are the Possible Causes of the DTC P2202 GMC?

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 P2202 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

There is a Factory Service Bulletin for the following GMC models:
2010 GMC Savana
2011 GMC Savana
2011 GMC Sierra
GMC Factory Service Bulletin OBDII Code P2202

What is the Cost to Diagnose the Code?

Labor: 1.0

To diagnose the P2202 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 P2202 GMC code?

Need more information on how to fix the P2202 GMC code? Get Access to Factory Service Manuals

Need Help with the Code?

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Information for Specific GMC Models

P2202 2014 GMC Sierra — NOx Sensor 1 Circuit Low Voltage
P2202 2015 GMC Sierra — NOx Sensor 1 Circuit Low Voltage
P2202 2016 GMC Sierra — NOx Sensor 1 Circuit Low Voltage
P2202 2017 GMC Sierra — NOx Sensor 1 Circuit Low Voltage
P2202 2018 GMC Sierra — NOx 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 P2202 GMC Code

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anewpher
Date: January 8, 2017 at 3:40 pm

2012 GMC 2500HD Duramax, it threw out P2202 after it stalled when I did a remote start on a cold (-3'F) morning. Text on the dash states that it will limit power in 175 miles. Two days later checked codes again and now it was showing two codes P2200 &P2202. I had been doing a lot of slow driving and using the remote start alot before this happened. Thinking that it's just particular matter built up. So I started driving harder - high speeds, fast acceleration, etc. The Check Engine light went out. It seems to be back to normal now except for the text telling me that it will limit power in 142 miles... The DEF fluid was "normal" before all this happened....I don't suspect anything there. I'll take it in to the shop to get the text cleared and find out more. If I can find my way back here, I'll update this.

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