AutoCodes – GMC – P105A GMC

P105A GMC 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: P105A GMC 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 736

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 P105A GMC 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 P105A GMC - Reductant Pump Low Speed - AutoCodes.com — P105A GMC Code - Reductant Pump Low Speed

What does this mean?

What are the Possible Causes of the DTC P105A GMC?

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 P105A GMC?

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 P105A GMC 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 P105A GMC Code

1. What are the common symptoms of OBDII code P105A GMC (Reductant Pump Low Speed)?

The common symptoms include poor engine performance, reduced fuel efficiency, and the illumination of the Check Engine Light.

2. What are the potential causes of OBDII code P105A GMC?

Potential causes of this code may include a faulty reductant pump, wiring issues, a defective reductant pump control module, or a problem with the reductant level sensor.

3. How can I diagnose OBDII code P105A GMC?

Diagnosing this code typically involves using a scan tool to retrieve the trouble code, inspecting the reductant pump and related components for any visible damage, and testing the wiring and connections for proper continuity.

4. What are some repair tips for addressing OBDII code P105A GMC?

Repair tips may include checking and replacing any damaged wiring or connectors, testing the reductant pump and control module for proper operation, and ensuring the reductant level sensor is functioning correctly.

5. Can I continue driving my vehicle with OBDII code P105A GMC?

It is not recommended to continue driving your vehicle with this code present, as it can lead to further damage and potential failure of emission control systems.

6. How serious is OBDII code P105A GMC?

While this code may not cause immediate drivability issues, it is important to address it promptly to prevent long-term damage to the vehicle's emissions system and ensure proper engine performance.

7. Will resetting the Check Engine Light clear OBDII code P105A GMC?

Resetting the Check Engine Light may temporarily turn it off, but if the underlying issue causing the P105A code is not addressed, the light is likely to come back on.

8. Can a DIY enthusiast fix OBDII code P105A GMC at home?

Depending on your skill level and access to tools, some DIY enthusiasts may be able to address this code at home by following repair guides and using diagnostic tools.

9. How much does it typically cost to repair OBDII code P105A GMC at a mechanic?

The cost of repairing this code can vary depending on the specific cause, but you can expect to pay for diagnostic time, parts, and labor, which may range from a few hundred to over a thousand dollars.

10. Is OBDII code P105A GMC covered under any warranties?

If your vehicle is still under warranty, the repair for this code may be covered, depending on the terms of your warranty. It's recommended to check with your dealership or warranty provider for more information.