AutoCodes – Generic – P1048

P1048 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 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 13,124

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 Aug 19, 2022

Description
Possible Causes
How To Fix
Cost to Diagnose
Comments
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Code P1048 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 - Reductant Injector High Control Circuit Low Voltage - AutoCodes.com — P1048 Code - Reductant Injector High Control Circuit Low Voltage

What does this mean?

What are the Possible Causes of the DTC P1048?

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?

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 P1048 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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Information for Specific Makes

P1048 Audi — Bank 1 Camshaft Adjustment Valve 1 Short To Positive
P1048 BMW — Valvetronic Control Circuit Low Input
P1048 Buick — Reductant Injector High Control Circuit Low Voltage
P1048 Cadillac — Reductant Injector High Control Circuit Low Voltage
P1048 Chevrolet — Reductant Injector High Control Circuit Low Voltage
P1048 Chrysler — Cylinder 2 Oil Supply Solenoid Valve Overcurrent
P1048 Dodge — Cylinder 2 Oil Supply Solenoid Valve Overcurrent
P1048 Fiat — Cylinder 2 Oil Supply Solenoid Valve Overcurrent
P1048 GMC — Reductant Injector High Control Circuit Low Voltage
P1048 Jeep — Cylinder 2 Oil Supply Solenoid Valve Overcurrent
P1048 MINI — Valvetronic Control Circuit Low Input
P1048 Volkswagen — Bank 1 Camshaft Adjustment Valve 1 Short To Positive

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.