AutoCodes – Generic – P1040

P1040 Code - Reductant Pump Control Circuit Shorted

Quick Answer

The selective catalytic reduction system reduces Oxides of Nitrogen (NOx) emissions by injecting a metered amount of reductant into the exhaust gas stream entering the selective catalytic reduction catalyst. 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: P1040 indicates Reductant Pump Control Circuit Shorted.
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 17,614

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 P1040 Description

The selective catalytic reduction system reduces Oxides of Nitrogen (NOx) emissions by injecting a metered amount of reductant into the exhaust gas stream entering the selective catalytic reduction catalyst. Within the selective catalytic reduction catalyst, the reductant reacts with the NOx to form nitrogen, carbon dioxide, and water vapor. Upstream and downstream NOx sensors provide the engine control module and the reductant control module via serial data. The Engine Control Module (ECM) controls the reductant injector duty cycle in response to changes in engine-out NOx levels. The reductant control module supplies system voltage to the reductant pump motor. The reductant control module controls the solenoid by grounding the control circuit. The reductant control module can determine if the control circuit is open, shorted to ground, or shorted to a voltage by monitoring the feedback voltage. The Diagnostic Trouble Code (DTC) will be set when the reductant control module detects a motor pump phases shorted error.

OBDII Code P1040 - Reductant Pump Control Circuit Shorted - AutoCodes.com — P1040 Code - Reductant Pump Control Circuit Shorted

What does this mean?

What are the Possible Causes of the DTC P1040?

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 P1040?

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 P1040 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 P1040 code?

Need more information on how to fix the P1040 code? Get Access to Factory Service Manuals

Need Help with the Code?

Get the P1040 code diagnosed by a professional: Find a repair shop in your area

Information for Specific Makes

P1040 Audi — Injector 1 Supply Voltage Circuit Malfunction
P1040 Buick — Reductant Pump Control Circuit Shorted
P1040 Cadillac — Reductant Pump Control Circuit Shorted
P1040 Chevrolet — Reductant Pump Control Circuit Shorted
P1040 Chrysler — Cylinder 4 Oil Supply Solenoid Valve Driver Short To Ground
P1040 Dodge — Cylinder 4 Oil Supply Solenoid Valve Driver Short To Ground
P1040 Fiat — Cylinder 4 Oil Supply Solenoid Valve Driver Short To Ground
P1040 GMC — Reductant Pump Control Circuit Shorted
P1040 Jeep — Cylinder 4 Oil Supply Solenoid Valve Driver Short To Ground
P1040 Volkswagen — Injector 1 Supply Voltage Circuit Malfunction

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 P1040 Code

1. What are some common symptoms of OBDII code P1040 (Reductant Pump Control Circuit Shorted)?

The common symptoms of code P1040 include the Check Engine Light illuminating on the dashboard, reduced engine performance, and potential issues with emissions control.

2. What could cause the OBDII code P1040 to trigger?

The code P1040 may be triggered due to a short circuit in the reductant pump control circuit, damaged wiring, or a faulty reductant pump control module.

3. How serious is the OBDII code P1040 (Reductant Pump Control Circuit Shorted)?

While the code itself may not cause immediate harm to the vehicle, it can lead to issues with emissions control and potentially impact the overall performance of the engine.

4. Can I continue driving my vehicle with the OBDII code P1040 present?

It is recommended to address the issue promptly to prevent any further damage to the emissions control system. Continuing to drive with the code present may lead to increased emissions and potential engine performance issues.

5. How can I diagnose and repair OBDII code P1040?

Diagnosing and repairing code P1040 involves inspecting the reductant pump control circuit for any shorts, checking the wiring for damage, and testing the reductant pump control module for proper functionality.

6. Is it possible to reset the OBDII code P1040 without addressing the underlying issue?

Simply clearing the code without addressing the root cause, such as a shorted circuit or faulty component, will likely result in the code reappearing once the vehicle is driven again.

7. Are there any DIY repair tips for fixing OBDII code P1040?

If you are familiar with automotive electrical systems, you may attempt to inspect the wiring and connectors associated with the reductant pump control circuit. However, for accurate diagnosis and repair, it is recommended to seek professional assistance.

8. Can extreme weather conditions contribute to triggering OBDII code P1040?

Extreme weather conditions, such as excessive heat or moisture, can potentially impact the electrical components involved in the reductant pump control circuit, leading to a short and triggering the P1040 code.

9. How long does it typically take to repair OBDII code P1040?

The repair time for OBDII code P1040 can vary depending on the exact cause of the issue. Simple fixes like repairing a damaged wire may take less time compared to replacing a faulty reductant pump control module.

10. Will fixing OBDII code P1040 improve fuel efficiency?

Addressing and repairing the underlying issue causing code P1040 may help restore the vehicle's emissions control system to optimal functioning, potentially leading to improved fuel efficiency over time.