← DEF / DPF warnings on all engines

Symptoms · 3.0 Power Stroke (2018-2021)

3.0 Power Stroke (2018-2021): def, dpf and regeneration warnings

2 documented failures on this engine list this among their signs. They are ordered from the most widespread down. Each one shows the signs in its record's own words, how to tell it from the others, the usual fix and any recall or bulletin.

1. DEF heater faults and harness corrosion (P20BA) Common · 1 recall/bulletin
2. DPF regeneration duty and oil dilution Occasional

Not sure which engine you have, or want the recalls for your exact truck? Check your VIN: it names the engine and lists the campaigns for that model year. Whether a recall is still open on your VIN: nhtsa.gov/recalls.

1 DEF heater faults and harness corrosion (P20BA)

verified How widespread: Common

How it shows up

• 'DEF fluid heater malfunction' in FordPass / Service Engine light, P20BA

Its other signs

• root cause is often corrosion in the DEF heater harness/connector wiring rather than the heater element itself

How to tell it apart

• TSB MC-10236685 first: inspect the heater harness/connector for corrosion before ordering the heater or tank unit

Usual fix

repair/replace the DEF heater harness per TSB MC-10236685 (connector corrosion is the common fault; splice work, no separate catalog part)

Recalls and bulletins

TSB MC-10236685

Root cause, parts and sources →

2 DPF regeneration duty and oil dilution

aggregated How widespread: Occasional

How it shows up

• rising oil level between services (fuel dilution from post-injection regens)
• frequent/short regen cycles under city duty

How to tell it apart

• track oil level between services (rising level = dilution, not a leak); shorter change intervals under city duty

Usual fix

oil and filter service on a shortened interval under city/short-trip duty (spec oil)

Root cause, parts and sources →

Everything on the 3.0 Power Stroke (2018-2021)Its recalls and bulletins

Order: how widespread each failure is in its record (near-universal, very common, common, occasional, rare), then the number of NHTSA owner complaints that match its keywords. Complaint counts are keyword matches, not a manual review of each complaint. A symptom listed here means the failure is documented with that sign; it is not a diagnosis of your truck. Tiers: verified, aggregated, contested, data-gap. How we tier and source facts.