1832311 | Genuine Paccar® Doser Injection Module For Kenworth & Peterbilt

1. Injects precise fluid into the exhaust

• DEF → reduces NOx emissions

• Fuel → helps burn soot in the DPF

2. Helps meet emissions regulations

The module ensures the engine complies with modern EPA/European emissions standards.

3. Works with the ECM

The engine computer controls the doser, commanding:

• When to inject

• How much to inject

• How long to inject

4. Maintains aftertreatment performance

A working doser is essential for:

• Preventing DPF clogging

• Proper DPF regen

• Reducing harmful emissions

1. Check Engine Light or DEF/DPF Warning Lights

A failing doser often triggers:

• Check Engine Light

• DEF system fault

• DPF regeneration required

• Exhaust aftertreatment alerts

2. Poor or Failed DPF Regeneration

A bad fuel doser cannot inject fuel properly, causing:

• DPF clogging

• Frequent forced regens

• Regen doesn’t start or won’t complete

• Excessive soot buildup

3. Loss of Power / Limp Mode

If the exhaust system can’t operate correctly, the ECM may limit power to protect the engine.

4. Increased Fuel Consumption

Caused by:

• Frequent regens

• Excessive dosing commands

• Engine running richer to compensate

5. Excessive Smoke from Exhaust

• Black smoke → improper fuel dosing

• White smoke → unburned DEF or faulty spray pattern

6. Strong Ammonia or Chemical Smell (DEF Doser)

If the DEF isn’t injected properly, you may smell ammonia around the exhaust.

7. Crystallization or Build-Up on the Doser

Especially on DEF dosers:

• White crust

• Crystals blocking the nozzle

• Poor spray pattern

8. Failed Emissions Test

Because the system cannot reduce NOx or burn soot efficiently.

9. Engine Derate / 5 MPH Limp Mode (Severe)

The truck may enter severe derate if the DEF or DPF system cannot function due to a dead doser module.