Buy wp20517 - Genuine Cummins ETR CNT MDL Wiring Harness - wisentpartscenter.com

Description

Genuine Cummins 3958221 Electronic Control Module Wiring Harness connects the engine ECM with the sensors, actuators, power, and ground circuits used by the engine-management system. The harness carries both low-voltage sensor signals and control commands, so correct connector fit, pinout, and branch routing are important for reliable engine operation.

Verify fitment with us before ordering to ensure the correct part for your application.

Purpose of the Part

The 3958221 is the electrical link between the ECM and the engine components it monitors and controls. It allows the ECM to receive information from sensors and send commands back to actuators, making the harness a critical part of the engine’s electronic control system.

Issue Symptoms / When to Replace

A damaged engine harness can cause intermittent fault codes, sensor readings that drop in and out, no-start conditions, actuator faults, or problems that appear only when the engine moves or heats up. Chafed wiring, loose terminals, corrosion inside connectors, and damaged grounds can all create symptoms that look like failed sensors or modules, so the harness should be inspected before replacing expensive electronic components.

Brand Information

Cummins has manufactured diesel engines and engine-control components since 1919. Its electronic engine systems rely on application-specific wiring harnesses to connect the ECM with sensors, actuators, power, and ground circuits, and these harnesses are matched to the engine’s connector layout and control configuration rather than being universal wiring assemblies.

How to Identify an OEM Part

The OEM harness can be identified by the factory sticker label showing the Cummins logo and the Cummins part number. Check the label on the harness for the matching OEM number.

Why Buy 3958221 From Wisent Parts Center?

  • 1 Year
    Warranty

  • Genuine Parts

    Authentic OEM parts

  • Final Sale

    Returns not accepted

Shop with confidence

Warranty & Return Information
Warranty Information

Wisent Parts offers a 1-year warranty on all parts from the date of delivery. This warranty covers orders placed directly through our website. If a part fails during this period, we’re here to help - whether it’s a replacement, repair, or refund. For full details, refer to the Warranty page.

Return Information

This part is sold as a final sale item and cannot be returned or refunded, including if it was ordered in error. Please confirm fitment before ordering - send us your VIN, engine serial number, or original part number and we will verify it for you. For full details, please refer to the Returns page.