AutoCodes – Buick – P1056 Buick

P1056 Buick 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 Buick 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 368

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 Buick 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 Buick - Reductant Pump Low Speed - AutoCodes.com — P1056 Buick Code - Reductant Pump Low Speed

What does this mean?

What are the Possible Causes of the DTC P1056 Buick?

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 Buick?

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 Buick 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 Buick Code

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

- Common symptoms include reduced engine performance, decreased fuel efficiency, and the illumination of the check engine light.

2. What can cause the OBDII code P1056 in a Buick indicating a Reductant Pump Low Speed issue?

- The code may be triggered by a faulty reductant pump, wiring issues, a blown fuse, or a malfunctioning control module.

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

- Diagnosis typically involves using an OBDII scanner to retrieve the code, inspecting the reductant pump and its components for any visible damage, and checking the wiring and connections for any issues.

4. What are some possible repair tips for addressing the OBDII code P1056 in a Buick indicating a Reductant Pump Low Speed problem?

- Repair tips may include replacing the reductant pump, repairing any damaged wiring or connections, checking and replacing fuses if necessary, and resetting the code with an OBDII scanner.

5. Can I continue driving my Buick with the OBDII code P1056 related to the Reductant Pump Low Speed issue?

- It is not recommended to drive your vehicle with this code present, as it can lead to further damage and increased emissions. It is advisable to address the issue promptly.

6. How much does it typically cost to repair the OBDII code P1056 Buick Reductant Pump Low Speed problem?

- The cost of repair can vary depending on the exact cause of the issue, but it may range from $200 to $600 or more, including parts and labor.

7. Will resetting the OBDII code P1056 in my Buick make the issue go away permanently?

- Resetting the code may temporarily turn off the check engine light, but if the underlying issue causing the code is not addressed, it is likely to reappear.

8. Can a DIY enthusiast fix the OBDII code P1056 Buick Reductant Pump Low Speed problem themselves?

- Depending on their skill level and access to tools, a DIY enthusiast may be able to address simpler causes of the code, such as checking and replacing fuses or inspecting wiring connections.

9. Is the OBDII code P1056 Buick Reductant Pump Low Speed a common issue in these vehicles?

- While it may not be as common as some other OBDII codes, issues related to the reductant pump low speed can occur in Buick vehicles and should be addressed promptly to maintain optimal performance.

10. How long does it typically take to repair the OBDII code P1056 Buick Reductant Pump Low Speed problem?

- The repair time can vary depending on the exact cause of the issue and the availability of parts, but it may take anywhere from a couple of hours to a full day at a mechanic's shop.