AutoCodes – Cadillac – P1056 Cadillac

P1056 Cadillac 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 Cadillac 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 606

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

What does this mean?

What are the Possible Causes of the DTC P1056 Cadillac?

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 Cadillac?

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 Cadillac 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 P1056 Cadillac code?

Need more information on how to fix the P1056 Cadillac code? Get Access to Factory Service Manuals

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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 Cadillac Code

1. What are the common symptoms of OBDII code P1056 Cadillac (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 emission system.

2. What does the OBDII code P1056 Cadillac indicate?

OBDII code P1056 indicates a problem with the reductant pump low-speed circuit in the Cadillac's emission control system.

3. What are the possible causes of OBDII code P1056 Cadillac?

Possible causes include a faulty reductant pump, wiring issues in the reductant pump circuit, a failed reductant pump control module, or a malfunctioning reductant pump pressure sensor.

4. How can I diagnose the OBDII code P1056 Cadillac?

Diagnosis typically involves using an OBDII scanner to read the code, inspecting the reductant pump and its components for any visible damage, and testing the wiring and connections in the reductant pump circuit.

5. What are the repair options for OBDII code P1056 Cadillac?

Repair options may include replacing the reductant pump, repairing or replacing damaged wiring, replacing the reductant pump control module, or addressing any issues with the reductant pump pressure sensor.

6. Can I continue driving with OBDII code P1056 Cadillac?

It is not recommended to continue driving with this code present, as it can affect the vehicle's emission system and performance. It is best to address the issue promptly.

7. How much does it typically cost to repair OBDII code P1056 Cadillac?

The cost of repair can vary depending on the specific cause of the code and the labor rates in your area. It is advisable to get a diagnostic from a qualified mechanic for an accurate estimate.

8. Is OBDII code P1056 Cadillac a common issue in Cadillac vehicles?

While not extremely common, this code can occur in Cadillac vehicles with reductant pump systems, particularly in models equipped with emission control systems.

9. Can a DIY enthusiast fix OBDII code P1056 Cadillac at home?

DIY enthusiasts with automotive repair experience may be able to address this code at home by following diagnostic procedures and repair steps outlined in the vehicle's service manual.

10. How can I prevent OBDII code P1056 Cadillac from recurring?

Regular maintenance, such as checking the reductant pump system for any signs of wear or damage, can help prevent the recurrence of OBDII code P1056 in your Cadillac.