TI
About Blog Reference VIN lookup Disclosure

DEF, DPF and why your truck derates

Every diesel here from the late 2000s on carries an exhaust aftertreatment system: a diesel particulate filter that traps soot and burns it off in regeneration, and - a few model years later, by maker - a selective catalytic reduction stage that injects diesel exhaust fluid (DEF) to cut NOx. When a sensor, a heater, a pump or the fluid itself misbehaves, the truck warns, counts down and derates. That is the whole 'why does my truck derate' question, and the answer differs by maker and by year.

This page groups what our records document, engine by engine: every DEF/DPF/SCR failure mode with its provenance tier, the components on record with their numbers and prices, the trouble codes the system throws, and the engines that predate the system entirely. The narrative version of the derate ladder lives in the blog guide; this page is the tiered index behind it.

Every row is a published record - see /disclosure/

Engines with aftertreatment (14)

6.7 Power Stroke

Components on record: DEF (Diesel Exhaust Fluid) Injector AL3Z-5J281-A, DPF Differential Pressure Sensor BC3Z-9J460-E - all campaigns on the recalls page, priced failures on /repair-costs/.

6.7 Cummins 2007.5-2018

Components on record: DEF Pump Assembly with Heater (2013-2018), 6.7 Cummins DPF Assembly - all campaigns on the recalls page, priced failures on /repair-costs/.

6.7 Cummins 2019+

Components on record: 6.7L Cummins DEF Pump Module, 2019+ (OEM Mopar) 68458603AB, 6.7L Cummins DPF Assembly, 2019+ (OEM Mopar, cab-split PNs) Mopar 68630312AA (Reg Cab) / 68630315AA (Crew Cab) / 68630316AA (Mega Cab) - all campaigns on the recalls page, priced failures on /repair-costs/.

Duramax L5P

Components on record: Duramax L5P DEF Controller (OEM) 85514348, 6.6L Duramax L5P NOx Sensor, Position 1 / Upstream (GM 12718742) - all campaigns on the recalls page, priced failures on /repair-costs/.

Duramax LML

Components on record: Duramax LML DEF Tank Module (OEM) 20760381, Duramax LML NOx Sensor (OEM, catalog gap) - all campaigns on the recalls page, priced failures on /repair-costs/.

Duramax 3.0 (LM2/LZ0)

Components on record: 3.0L Duramax DEF Tank Assembly, pickups 2022-2024 (GM 87867197), 3.0L Duramax NOx Sensor, Position 1 (GM 24001898) - all campaigns on the recalls page, priced failures on /repair-costs/.

6.4 Power Stroke (DPF, no DEF)

Components on record: 6.4L Power Stroke Diesel Particulate Filter (OEM) 9C3Z-5H221-A - all campaigns on the recalls page, priced failures on /repair-costs/.

Duramax LB7-LMM (LMM = DPF era)

Components on record: Duramax LMM DPF Differential Pressure Sensor (OEM) 12598445 - all campaigns on the recalls page, priced failures on /repair-costs/.

3.0 Power Stroke (F-150)

Components on record: F-150 3.0L Power Stroke DEF Pump / Sender Assembly (Ford HC3Z-5J229-B, 2018-2021) - all campaigns on the recalls page, priced failures on /repair-costs/.

3.0 EcoDiesel (Ram 1500)

Components on record: Ram 1500 EcoDiesel DEF Pump (Mopar 68240043AC, 2018-2019) - all campaigns on the recalls page, priced failures on /repair-costs/.

ProMaster EcoDiesel

Components on record: F1C DEF Supply Pump (68438682AA, current) - all campaigns on the recalls page, priced failures on /repair-costs/.

Sprinter 3.0 V6 (OM642)

Components on record: Sprinter DEF Supply Pump (002-470-68-94-64) - all campaigns on the recalls page.

Sprinter 2.1 (OM651)

Components on record: Sprinter DEF Supply Pump, facelift (000-470-04-00) - all campaigns on the recalls page.

3.2 Power Stroke (Transit)

Components on record: 3.2L Power Stroke DEF Tank Hardware Kit (CK4Z-5L227-F) - all campaigns on the recalls page.

Prices are Dave's Auto Center retail, the same as in his store (the only seller this site links); a component without a price is not listed there - its page has a link to ask Dave's for it by number.

Trouble codes the emissions system throws

P204F, P20EE, P2200, P242F, P2463 - each code page lists the engines whose records name it and what the record says it points to.

Engines without DEF or DPF (3 diesel + all gas)

The derate ladder and the countdown messages differ by maker; the per-engine records above carry the exact behavior, and the blog guide tells it as a story. This page is the index: open the failure page before buying anything, and mind the tier on every fact.