GM GENUINE PARTS DEF Supply Pump Module 84545446 — OE Replacement for Diesel Emission Systems, Direct-Fit Durability

The GM Genuine Parts 84545446 Emission Reduction Fluid Supply Pump Module is an original-equipment replacement DEF pump designed to restore proper diesel exhaust fluid delivery and maintain your vehicle’s emission control performance.

This pump module is a factory-grade replacement developed to the specifications used by General Motors for select diesel-equipped vehicles. It supplies diesel exhaust fluid (DEF) from the tank to the dosing system, helping the vehicle’s selective catalytic reduction hardware operate as intended. Built for fit, form, and function parity with the original part, this GM Genuine Parts component is intended to deliver the durability and reliability expected of an OE switch-out. Note: contains a Proposition 65 warning for California — see product labeling for details.

How does this pump module affect my vehicle’s emission system?

The DEF supply pump provides metered fluid to the aftertreatment system that assists in reducing NOx emissions. If the pump fails or performs below specification, the dosing system can be compromised, triggering warning messages and potentially affecting emissions compliance. Replacing it with an OE-grade unit helps reestablish correct DEF delivery and system operation.

• Direct replacement for GM-specified DEF pump modules
• Engineered to meet original flow and pressure requirements
• Helps prevent system faults and emission-related diagnostics

What makes GM Genuine Parts 84545446 different from aftermarket alternatives?

This 84545446 module is produced to GM’s original engineering standards, which ensures the same mounting points, electrical connections, and performance parameters as the factory unit. Aftermarket pumps may vary in tolerances or materials and can require modifications or lead to fitment issues. Choosing a GM Genuine Parts component reduces the risk of installation problems and mismatched performance.

• Manufactured to GM OE specifications for reliable fit and operation
• Designed for the same service life and durability as the factory item
• Backed by GM parts sourcing and part-number verification

How do I know when the DEF supply pump needs replacement?

Warning indicators, reduced DEF pressure, or diagnostic trouble codes related to the dosing circuit commonly point to pump problems. You may also notice service messages, poor aftertreatment performance, or audible signs from the pump area. Proper diagnosis with a scan tool or inspection by a qualified technician confirms whether the pump or another component is at fault.

• Warning lights or emission-related fault codes on the instrument cluster
• Low or inconsistent DEF pressure readings during diagnostics
• Visible leaks, unusual noises, or failure to prime when system is active

What should I expect during installation and maintenance?

Installation typically follows the original routing and electrical connections, so no custom modifications are usually required when using this OE module. Basic precautions include depressurizing the DEF system, using clean DEF fluid, and checking seals and wiring harnesses. After installation, run a system check to clear codes and confirm proper dosing operation.

• Replaces factory pump using existing mounting and connectors
• Requires clean DEF fluid and attention to sealing surfaces
• Post-installation system scan recommended to verify operation

Who is this for? The GM Genuine Parts 84545446 Emission Reduction Fluid Supply Pump Module is intended for owners, fleet managers, and technicians working on GM diesel models that require a direct-fit DEF pump replacement. It’s the right choice when you want an OEM-quality component to preserve original performance, ensure proper emission-system function, and minimize installation uncertainty. If you need to address DEF delivery faults or restore factory-spec dosing behavior, this GM-specified module is engineered for that purpose.