AutoCodes – GMC – P1048 2015 GMC Sierra

P1048 2015 GMC Sierra Code - Reductant Injector High Control Circuit Low Voltage

Quick Answer

The Reductant Injector is a component of selective catalytic reduction system used to dose the reductant fluid to the exhaust gas and participate in the reduction reactions. Common causes include Faulty Reductant Injector, Reductant Injector harness is open or shorted, Reductant Injector 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: P1048 2015 GMC Sierra indicates Reductant Injector High Control Circuit Low Voltage.
Common causes: Common causes include Faulty Reductant Injector, Reductant Injector harness is open or shorted, Reductant Injector 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 150

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 Oct 01, 2022

Description
Possible Causes
How To Fix
Tech Notes ▶
Cost to Diagnose
FAQs
Comments
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Code P1048 2015 GMC Sierra Description

The Reductant Injector is a component of selective catalytic reduction system used to dose the reductant fluid to the exhaust gas and participate in the reduction reactions. The Engine Control Module (ECM) calculates the injection time of the reductant injector based on the measurement of the NOx sensors. To activate the injector the ECM supplies a PWM signal to the high control circuit and the low control circuit is always commanded ON. The Diagnostic Trouble Code (DTC) will be set when the Reductant Control Module detects a short to ground in the high control circuit.

OBDII Code P1048 2015 GMC Sierra - Reductant Injector High Control Circuit Low Voltage - AutoCodes.com — P1048 2015 GMC Sierra Code - Reductant Injector High Control Circuit Low Voltage

What does this mean?

What are the Possible Causes of the DTC P1048 2015 GMC Sierra?

Faulty Reductant Injector
Reductant Injector harness is open or shorted
Reductant Injector circuit poor electrical connection
Faulty Engine Control Module (ECM)

How to Fix the DTC P1048 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 does this mean?

Code Tech Notes

User Submitted Video

What is the Cost to Diagnose the Code?

Labor: 1.0

To diagnose the P1048 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.

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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 P1048 2015 GMC Sierra Code

What does OBDII code P1048 mean on a 2015 GMC Sierra?

Code P1048 indicates a problem with the reductant injector high control circuit, specifically low voltage detected.

What are the common symptoms of code P1048 on a 2015 GMC Sierra?

Symptoms may include the check engine light turning on, reduced engine performance, and issues with the diesel exhaust fluid (DEF) system.

What causes code P1048 on a 2015 GMC Sierra?

Common causes include a faulty reductant injector, damaged wiring or connectors in the control circuit, a failed reductant control module, or a blown fuse.

Can driving with code P1048 damage my 2015 GMC Sierra?

Driving with this code may not cause immediate damage but can lead to increased emissions, reduced DEF system efficiency, and potential long-term harm to the emissions system if not addressed.

How do I diagnose code P1048 on a 2015 GMC Sierra?

Start by inspecting the wiring and connectors for damage or corrosion, check the fuse for the reductant injector circuit, and test the reductant injector and control module for proper operation.

What tools are needed to fix code P1048 on a 2015 GMC Sierra?

You may need an OBDII scanner, a multimeter for voltage testing, and basic hand tools for inspecting and replacing components.

How can I fix code P1048 on a 2015 GMC Sierra?

Repairs may include replacing a damaged reductant injector, repairing or replacing faulty wiring or connectors, or replacing a failed reductant control module.

Is code P1048 specific to the 2015 GMC Sierra?

No, this code can appear on other vehicles with a similar DEF system, but the specific diagnostic and repair steps may vary.

How much does it cost to fix code P1048 on a 2015 GMC Sierra?

Repair costs can range from $100 to $500 or more, depending on whether the issue is with wiring, the reductant injector, or the control module.

Can a software update fix code P1048 on a 2015 GMC Sierra?

In some cases, a software update for the reductant control module may resolve the issue, but this depends on the specific circumstances and should be confirmed by a dealership or qualified technician.