AutoCodes – Chevrolet – P1056 Chevrolet

P1056 Chevrolet Code - Reductant Pump Low Speed

Quick Answer

The reductant pump motor is controlled by the reductant control module. Common causes include Faulty Reductant Pump and Sensor Assembly, Reductant Pump and Sensor Assembly harness is open or shorted, Reductant Pump and Sensor Assembly 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: P1056 Chevrolet indicates Reductant Pump Low Speed.
Common causes: Common causes include Faulty Reductant Pump and Sensor Assembly, Reductant Pump and Sensor Assembly harness is open or shorted, Reductant Pump and Sensor Assembly 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 1,243

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 Jul 24, 2021

Description
Possible Causes
How To Fix
Cost to Diagnose
FAQs
Comments
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Code P1056 Chevrolet Description

The reductant pump motor is controlled by the reductant control module. The Engine Control Module (ECM) sends a command to the reductant control module via a direct wire connection. This command is converted by the reductant control module into the desired pump speed The ECM checks the state of the wire to the reductant control module for circuit continuity. The signal sent by the ECM to the reductant control module is diagnosed for open circuit, short circuit to ground, and short circuit to voltage. The Diagnostic Trouble Code (DTC) will be set when the reductant control module detects that the reductant pump rotor is stalled for greater than 5 s.

OBDII Code P1056 Chevrolet - Reductant Pump Low Speed - AutoCodes.com — P1056 Chevrolet Code - Reductant Pump Low Speed

What does this mean?

What are the Possible Causes of the DTC P1056 Chevrolet?

Faulty Reductant Pump and Sensor Assembly
Reductant Pump and Sensor Assembly harness is open or shorted
Reductant Pump and Sensor Assembly circuit poor electrical connection
Faulty Reductant Control Module

How to Fix the DTC P1056 Chevrolet?

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 P1056 Chevrolet 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 P1056 Chevrolet Code

1. What are the common symptoms of OBDII code P1056 in a Chevrolet related to the Reductant Pump Low Speed?

The common symptoms include the illumination of the check engine light, reduced engine performance, and potential issues with the vehicle's emissions system.

2. What could be the possible causes of the OBDII code P1056 in a Chevrolet indicating Reductant Pump Low Speed?

Possible causes may include a faulty reductant pump, wiring issues, a malfunctioning reductant pump control module, or a problem with the reductant pump relay.

3. How can I diagnose the OBDII code P1056 in a Chevrolet related to the Reductant Pump Low Speed?

Diagnosis typically involves using a diagnostic scanner to retrieve the specific fault code, inspecting the reductant pump and its components for any visible damage, and testing the electrical connections for proper voltage and continuity.

4. Can I continue driving my Chevrolet if the OBDII code P1056 for Reductant Pump Low Speed is present?

It is not recommended to continue driving the vehicle with this fault code present, as it can lead to increased emissions, reduced fuel efficiency, and potential damage to other components in the emissions system.

5. What are some repair tips for addressing the OBDII code P1056 in a Chevrolet related to Reductant Pump Low Speed?

Repair tips may include checking and replacing the reductant pump if necessary, inspecting and repairing any damaged wiring or connections, resetting the fault code after repairs, and conducting a test drive to ensure the issue is resolved.

6. Is it possible to reset the OBDII code P1056 in a Chevrolet indicating Reductant Pump Low Speed without repairing the issue?

While you can clear the fault code with a diagnostic scanner, it is not recommended to do so without addressing the underlying problem, as it may lead to continued issues with the vehicle's emissions system.

7. How much does it typically cost to repair the OBDII code P1056 in a Chevrolet for Reductant Pump Low Speed?

Repair costs can vary depending on the exact cause of the issue, but they may range from a few hundred to over a thousand dollars, including parts and labor.

8. Can a DIY enthusiast fix the OBDII code P1056 in a Chevrolet related to Reductant Pump Low Speed?

While some DIY enthusiasts may be able to diagnose and address simpler causes of the code, it is recommended to consult a professional mechanic for proper diagnosis and repair, especially when dealing with emissions-related issues.

9. Will the OBDII code P1056 in a Chevrolet for Reductant Pump Low Speed affect the vehicle's overall performance?

Yes, the presence of this fault code can impact the vehicle's overall performance by reducing engine efficiency, increasing emissions output, and potentially triggering a limp mode to protect the engine.

10. How often does the OBDII code P1056 in a Chevrolet indicating Reductant Pump Low Speed occur?

The occurrence of this fault code can vary depending on the vehicle's age, maintenance history, and driving conditions, but it is relatively common in Chevrolet vehicles with emissions system issues.