P242F

Code

LAND ROVER P — Powertrain

Diesel particulate filter restriction - ash buildup

Brand: LAND ROVER

Type: P — Powertrain

Views: UK: 19 EN: 68 RU: 63

AI status

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Page language: EN

Causes

Long service interval / high mileage DPF (ash accumulates over life)
Extended low-speed driving / infrequent high-load runs (reduced passive/active regen)
Excessive oil consumption or burnt oil (adds ash and ash-forming additives)
Use of incorrect engine oil or oil with ash-forming additives
Worn piston rings, valve guides or turbo seals (oil burning)
Failed or out-of-spec DPF differential pressure sensor or wiring giving false readings

Symptoms

MIL (check engine) illuminated; P242F stored
Reduced engine power or limp mode (torque derate)
Poor fuel economy
Difficulty maintaining or completing active regen
Heavier-than-normal exhaust smoke after acceleration
Increased exhaust backpressure; possible turbo underperformance

What to check

Read all stored and pending codes and freeze-frame data with OEM-level scan tool
Check for related codes (DPF pressure/temp sensors, EGR, fuel control, turbo)
Inspect DPF differential pressure (delta-P) at idle and under load
Monitor upstream and downstream exhaust temperature sensors during a forced regen attempt
Check engine oil level and sample for soot/contamination; check oil consumption history
Visually inspect exhaust backpipe and DPF for external damage or soot leaks

Signal parameters

DPF differential pressure (mbar or kPa) — compare idle vs higher RPM/load
Upstream exhaust temperature (°C) and downstream exhaust temperature (°C)
Calculated soot load (%) or soot mass (g) if available from scan tool
Engine load / RPM during diagnostic drive cycle
Active regeneration status and commanded regen duration
Fuel trim / injector control parameters (to detect over-fueling)

Diagnostic algorithm

Retrieve all DTCs and freeze frame; note conditions when P242F set.
Verify sensor circuit integrity: probe DPF differential pressure sensor and exhaust temperature sensors; check connectors and wiring for damage or corrosion.
Measure DPF differential pressure at key operating points (cold idle, 2000–2500 rpm) and compare to manufacturer limits; a high delta-P when cold and under load suggests restriction.
Attempt a controlled forced/active regeneration with OEM scan tool while monitoring temperatures and delta-P. If regen cannot be sustained or delta-P does not fall, restriction likely significant.
Inspect for causes of excessive ash: check engine oil level and sample for soot/oil contamination; review oil change history and oil specification used.
Check for causes of soot overproduction (EGR faults, injector leaks, turbo issues, misfires) and repair as needed before DPF service to avoid repeat blockage.
If sensors are faulty, replace or repair and retest; clear codes and repeat regen attempt.
If ash limitation suspected and cannot be removed by passive/active regen, consider professional DPF cleaning (specialized thermal/chemical cleaning) or DPF replacement per manufacturer guidance.
After cleaning or replacement, perform post-service forced regen and road test; verify delta-P and clear codes; confirm no recurring faults.
Safety note: DPF work involves very hot components and confined spaces—use PPE and follow safe procedures.

Likely causes

DPF has reached end-of-life ash capacity (service life exceeded)
High oil consumption / oil burning depositing ash in DPF
Faulty DPF differential pressure or temperature sensors or wiring
Frequent short trips preventing regeneration causing heavy soot then ash after burn cycles

Fault status

⚠️ Status

Diesel particulate filter restriction detected — ash accumulation. Increased DPF differential pressure above threshold; regeneration insufficient or impossible. MIL on.

🔴 Repair difficulty: Hard

⏱️ Diagnostic time: 2-6 hours

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P242F — Diesel particulate filter restriction - ash buildup