AutoCodes – GMC – P1193 GMC

P1193 GMC Code - O2 Low Reference Circuit Low Voltage (NOx Sensor 1)

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: P1193 GMC indicates O2 Low Reference Circuit Low Voltage (NOx Sensor 1).
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.

Save to My Repairs My Repairs

AI answers can be wrong. Verify repairs with testing. Open full chat

Code Popularity 420

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 29, 2024

Description
Possible Causes
How To Fix
Cost to Diagnose
FAQs
Comments
Add Comment

💬 Need more help? Ask Coddy for instant answers — it's free!

Code P1193 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 P1193 GMC - O2 Low Reference Circuit Low Voltage (NOx Sensor 1) - AutoCodes.com — P1193 GMC Code - O2 Low Reference Circuit Low Voltage (NOx Sensor 1)

What does this mean?

What are the Possible Causes of the DTC P1193 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 P1193 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 P1193 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 P1193 GMC code?

Need more information on how to fix the P1193 GMC code? Get Access to Factory Service Manuals

Need Help with the Code?

Get the P1193 GMC code diagnosed by a professional: Find a repair shop in your area

Information for Specific GMC Models

P1193 2014 GMC Sierra — O2 Low Reference Circuit Low Voltage (NOx Sensor 1)
P1193 2015 GMC Sierra — O2 Low Reference Circuit Low Voltage (NOx Sensor 1)
P1193 2016 GMC Sierra — O2 Low Reference Circuit Low Voltage (NOx Sensor 1)
P1193 2017 GMC Sierra — O2 Low Reference Circuit Low Voltage (NOx Sensor 1)
P1193 2018 GMC Sierra — O2 Low Reference Circuit Low Voltage (NOx Sensor 1)

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 P1193 GMC Code

1. What are the common symptoms of OBDII code P1193 in a GMC vehicle?

The common symptoms of OBDII code P1193 (O2 Low Reference Circuit Low Voltage - NOx Sensor 1) in a GMC vehicle may include poor fuel efficiency, rough idling, and an illuminated check engine light.

2. What are the possible causes of OBDII code P1193 in a GMC vehicle?

Possible causes of OBDII code P1193 in a GMC vehicle include a faulty NOx sensor, damaged wiring or connectors in the O2 sensor circuit, or a malfunctioning engine control module (ECM).

3. How can I diagnose OBDII code P1193 in my GMC vehicle?

Diagnosing OBDII code P1193 in a GMC vehicle typically involves using an OBDII scanner to retrieve the trouble code and then inspecting the NOx sensor, wiring, and connectors for any signs of damage or malfunction.

4. Can I continue driving my GMC vehicle with OBDII code P1193?

It is not recommended to continue driving your GMC vehicle with OBDII code P1193, as it can lead to decreased fuel efficiency and potential damage to other components of the vehicle.

5. How can I repair OBDII code P1193 in my GMC vehicle?

Repairing OBDII code P1193 in a GMC vehicle may involve replacing the faulty NOx sensor, repairing or replacing damaged wiring or connectors, or reprogramming the ECM to address the issue.

6. Is it possible to reset OBDII code P1193 in a GMC vehicle without fixing the underlying issue?

While it is possible to clear the OBDII code P1193 in a GMC vehicle with an OBDII scanner, the underlying issue causing the code will need to be addressed to prevent it from reoccurring.

7. How much does it typically cost to repair OBDII code P1193 in a GMC vehicle?

The cost of repairing OBDII code P1193 in a GMC vehicle can vary depending on the specific cause of the issue, but it may range from a few hundred to a few thousand dollars, including parts and labor.

8. Can a DIY enthusiast repair OBDII code P1193 in a GMC vehicle?

While some DIY enthusiasts may have the skills and tools to diagnose and repair OBDII code P1193 in a GMC vehicle, it is recommended to consult a professional mechanic for complex electrical issues like this.

9. Are there any preventative maintenance tips to avoid OBDII code P1193 in a GMC vehicle?

To help prevent OBDII code P1193 in a GMC vehicle, regular maintenance and inspections of the NOx sensor, O2 sensor circuit, and ECM are recommended, along with following the manufacturer's recommended service schedule.

10. How long does it typically take to repair OBDII code P1193 in a GMC vehicle?

The time it takes to repair OBDII code P1193 in a GMC vehicle can vary depending on the specific cause of the issue and the availability of parts. In general, it may take a few hours to a full day for a mechanic to diagnose and repair the problem.