PROTOCOLO DE TALLER DIESEL OBD-II8-10 min read
P0269Fallo de CombustiónSeveridad Alta💡 Luz de avería encendida

P0269: Fallo de contribución / balance del cilindro 3

El código de diagnóstico DTC P0269 indica que el módulo de control del motor (ECM/PCM) ha detectado que el cilindro 3 no entrega el impulso de par mecánico esperado hacia el cigüeñal, generando un desequilibrio de rotación intercilindros. En motores diésel de riel común, el ECM calcula continuamente el trabajo individual de cada cilindro monitoreando variaciones en el orden de submicrosegundos en la aceleración angular del cigüeñal mediante el sensor de posición del cigüeñal (CKP) durante la carrera de expansión/combustión, entre 30° - 90° después del punto muerto superior (ATDC). Si el algoritmo de control de marcha suave (SRC) / calibración de caudal cero (ZFC) del ECM debe aplicar una compensación de combustible excesiva (típicamente > +3.0 - +4.5 mg/embolada) para estabilizar el ralentí, o si la contribución del cilindro desciende entre 15% - 25% por debajo del promedio del motor, se registra el código P0269.

🚗 PROTOCOLO CONDUCTOR Y REPARACIÓN

🚗 Seguridad operativa, presupuesto estimado y verificación

🟡 Precaución: Modo emergencia activo / Acudir a taller
  1. 01

    🚦 Seguridad de conducción y riesgo mecánico

    Evaluación mecánica inmediata y necesidad de grúa

    Fallo de contribución / equilibrio del cilindro 3 - Déficit de entrega de par

    La ECU detectó que el cilindro 3 no produce suficiente momento de rotación. El suministro de combustible ha disminuido o un retorno excesivo está privando a la cámara de combustión del volumen de diésel necesario.

    PELIGROS MECÁNICOS SI CONTINÚA CONDUCIENDO:El combustible no quemado continuo o los fallos de encendido por mezcla pobre pueden provocar sobrecalentamiento del catalizador o saturación de hollín en el DPF.
  2. 02

    💰 Presupuesto típico de taller

    Niveles de costo esperados para repuestos y mano de obra
    Mantenimiento menor / Filtro40 € - 110 €: Limpieza química del sistema de combustible y sustitución del filtro

    Limpieza de sensor, cambio de filtro de combustible, revisión de fusibles o conectores.

    Cambio de válvula / Sensor180 € - 480 €: Sustitución del inyector del cilindro 3 por recambio original

    Sustitución de componente individual (válvula reguladora, unidad dosificadora o inyector reconstruido).

    Reparación mayor / Bomba e inyectores850 € - 2.200 €: Revisión de la compresión mecánica del motor o trabajos en la culata

    Revisión de bomba de alta presión, juego de inyectores nuevos o sustitución del conjunto DPF.

    Tarifas de referencia de talleres. Más del 70% de las incidencias se resuelven en Nivel 1 o 2 sin sustituir subconjuntos completos.

  3. 03

    🧰 Verificaciones visuales rápidas en garaje

    Chequeo de 5 minutos sin herramientas antes de ir al taller
    11. Comprobar la corrección de caudal del inyector en tiempo real: una desviación superior a +3,0 mg/str apunta a una tobera obstruida o un retorno excesivo.
    22. Inspeccionar el asiento del inyector del cilindro 3 en busca de burbujeo de diésel o acumulación de carbonilla tipo chapapote.
    33. Intercambiar el inyector del cilindro 3 con el del cilindro 1; si el código de avería migra a P0263, se demuestra que el inyector está defectuoso.
  4. 04

    🛡️ Protección ante diagnósticos erróneos en taller

    Preguntas técnicas exactas para evitar sustituciones de piezas innecesarias
    ""Facilite los registros de datos del equilibrado de cilindros antes y después de la limpieza química antes de indicar la sustitución del inyector.""
    ""Confirme si la compresión mecánica en el cilindro 3 está dentro del 10 % respecto a los cilindros adyacentes.""
    ""Asegúrese de rectificar el asiento del nuevo inyector con la fresa adecuada si el fogueo de gases de combustión ha erosionado la superficie de la culata.""

    Nota técnica: Haga estas preguntas técnicas a su mecánico antes de autorizar presupuestos caros:

🔧 PROTOCOLO TÉCNICO PROFESIONAL Y TALLERRAPID ASSESSMENT

Triaje de taller en 30 segundos

Síntomas principales
  • Noticeable engine shudder, rough idle, and cabin vibration during warm idle (especially in Drive at traffic lights)
  • Hesitation, flat spots, or rhythmic surging during light-to-moderate throttle cruising at 1200 to 2000 RPM
  • Check Engine Light (MIL) illuminated, occasionally accompanied by flashing glow plug light or traction control warning
Causas más probables
  • Partially clogged, carbon-coked, or eroded spray holes in the Cylinder 3 fuel injector nozzle tip
  • Excessive internal control valve wear (backleak) in Cylinder 3 injector, reducing effective injection pressure and fuel delivery
  • Incorrect, corrupted, or uncalibrated IMA / QR injector calibration code programmed into the ECM for Cylinder 3
Primera acción requerida

Connect scan tool live telemetry: compare Target Fuel Rail Pressure vs Actual Rail Pressure and log metering valve command PWM duty cycle during idle and road load.

Expensive Diagnostic Pitfall & Technical Reality

❌ Error común en el taller:

P0269 means Cylinder 3 has low mechanical compression requiring engine teardown or full injector set replacement ($3,000 - $5,500).

🔍 Realidad técnica e hidráulica:

P0269 is an electronic cylinder balancing limit code (Smooth Running Control). The ECM measures crankshaft micro-acceleration after Cylinder 3 fires and adjusts fuel trim (mg/stroke) to keep engine idle smooth. If the required trim exceeds calibrated limits (typically >±4.5 mg/stroke), P0269 is flagged. In over 80% of verified cases, mechanical compression is normal. The root cause is an incorrectly typed or missing IMA/IQA injector code in the ECM, a partially clogged injector nozzle spray hole, or excessive control valve backleak.

💡 Protocolo de verificación técnica:

Unnecessary engine teardown ($3,500+) vs verifying and reprogramming the 7-to-20-character IMA injector code into the ECM ($0 - $50) or rebuilding the injector ($120), saving thousands.

Severe Piston Crown Thermal Erosion & Bore Washing Hazard

CRITICAL WORKSHOP WARNING: Never ignore a Cylinder 3 contribution fault code P0269! In diesel combustion, if the balance fault is caused by a worn or carbon-fouled injector nozzle needle that is dripping or failing to atomize fuel into a fine 10-micron mist, raw liquid diesel sprays directly against the aluminum piston bowl.

MANDATORY PROTOCOL: Under highway load, this creates an intense localized torching fire that melts the piston crown (holed piston) or washes oil film off the cylinder wall, causing catastrophic cylinder bore scoring and crankcase blow-by. If the engine emits black smoke under throttle or if the oil dipstick level is rising with diesel smell, discontinue driving immediately and perform an injector backleak and flow test.

PLATFORM ARCHITECTURE

Motores y plataformas de inyección más afectados

Este código de error afecta principalmente a las siguientes plataformas diésel common rail. Consulte su familia de motores para ver fallos típicos y referencias de piezas:

Mercedes-Benz 2.1 CDI (OM651 / OM646)

Delphi CRD2 / Bosch Common Rail Injection

Fallo típico de fábrica: Delphi piezo to solenoid conversion wiring harness chafing, differential pressure sensor internal diaphragm drift.

Componente clave:A6510704987, A6510700587, A0061539528

Ford 6.7L Powerstroke V8 Diesel

Bosch CP4.2 High-Pressure Common Rail System

Fallo típico de fábrica: EGR cooler carbon clogging, DEF injector white crust crystallization, fuel volume control valve harness chafing.

Componente clave:BC3Z-9A543-A, FC3Z-9F593-B, BC3Z-5J281-A

Volkswagen / Audi 2.0 TDI (EA189 / CFFB / CFGB)

Bosch EDC17 Common Rail System

Fallo típico de fábrica: Piezo stack degradation, injector harness terminal fretting, DPF differential pressure sensor silicone tube split.

Componente clave:03L130277, 0445110369, 076906051A

BMW 2.0d / 3.0d (N47 / N57 / M57TU2)

Bosch CRI2.5 / CRI3.0 Common Rail

Fallo típico de fábrica: Injector balance drift beyond +/- 4.0 mg/stroke, glow plug control unit (BERU) power lead failure, DPF backpressure accumulation.

Componente clave:13537805428, 0445116024, 12217801201
WORKSHOP MASTER TEARDOWN GUIDE

Cylinder Balance & Injector Deviation Guide

Common rail diesel cylinder balance & smooth running diagnostic guide. Balance rates, mg/stroke deviation, P0263 misfire, compression vs injector test.

Read Full Master Guide →
THEORY OF OPERATION

Circuito de control y lógica del actuador

1. Dynamic In-Demand Fuel Metering

Modern common rail diesel engines operate without a physical distributor or mechanical governor; cylinder-to-cylinder torque equalization is performed purely through software. The ECM monitors flywheel tooth passage times using a high-precision magnetic or Hall-effect CKP sensor reading a 60-2 or 36-2 target wheel. If Cylinder 3 produces less power due to a partially coked injector nozzle, excessive internal hydraulic backleak, or slightly degraded mechanical compression, the crankshaft slows down momentarily during Cylinder 3's power segment. The ECM immediately compensates by extending the injection duration for Cylinder 3.

2. Closed-Loop PID Deviation Monitoring

The Smooth Running Control (SRC) algorithm calculates a real-time fuel trim offset for each cylinder (displayed in scan tools as 'Cylinder Balance Rate' or 'Injector Quantity Offset', typically scaled in mg/stroke or mm³/stroke). A healthy cylinder operates between -1.5 mg/stroke and +1.5 mg/stroke. When Cylinder 3's required fuel correction exceeds calibrated upper limits (+3.5 to +6.0 mg/stroke) for longer than 500 consecutive combustion cycles at warm idle, or during an automated cylinder cutout diagnostic sweep, the ECM flags P0269 and locks the balance rate into freeze frame memory.

3. Diagnostic Trap: Normally Open (NO) vs Normally Closed (NC) Valves

Contribution Fault (P0269) vs Misfire (P0303) Diagnostic Distinction: Technicians frequently confuse these two codes. P0303 indicates a COMPLETE combustion failure (misfire/dead miss, zero flame propagation), usually caused by an electrical open circuit, completely blocked injector, or zero compression. In contrast, P0269 indicates PARTIAL combustion: fuel is injecting and igniting, but the kinetic energy delivered is suboptimal compared to companion cylinders. In over 75% of diesel cases, P0269 is caused by mechanical injector nozzle varnish or excessive control valve return leakage, NOT electrical circuit failure.

ENGINEERING SPECIFICATIONS

Valores físicos eléctricos e hidráulicos

Solenoid Coil DC ResistanceCommon Rail Solenoid Injector: 0.20 - 0.45 Ω @ 20°C; Piezo Injector: 180 kΩ - 220 kΩ (Capacitance: 2.5 - 3.5 µF)Measured @ 20°C across terminals 1 & 2
Insulation Resistance> 10 MΩ measured between injector electrical pins and cylinder head metal chassis (ground)Between terminals and pump body (ground)
Operating Supply Voltage80 V - 90 V DC peak boost voltage (Solenoid) or 140 V - 200 V DC (Piezo); Battery supply to ECM: > 12.0 VHigh-side feed from ECM / main relay
PWM Frequency StandardMulti-pulse high-speed current waveform; Peak pull-in current: 20 A - 30 A; Hold current: 10 A - 12 ASquare-wave PWM modulation
Idle Duty Cycle (Warm Engine)Cylinder 3 Balance Fuel Trim (SRC): Normal is -1.5 to +1.5 mg/stroke; Fault threshold > +3.0 to +4.5 mg/strokeNominal baseline at 250–350 bar
Full-Load Duty Cycle (WOT)Dynamic Backleak Flow Limit: < 25 mL/min per injector @ warm idle; < 5 mL total per cylinder during 15s starter crankingMaximum high-speed fuel delivery demand
Low-Pressure Feed SupplyMechanical Cylinder Compression: 22.0 to 32.0 bar (320-465 psi); Maximum allowable variance to other cylinders < 3.0 bar (< 10%)Measured at pump fuel inlet
Internal Cascade BackpressureCylinder Cutout RPM Drop: Must produce a 45 to 65 RPM drop when Cylinder 3 is disabled via scan toolControlled by overflow cascade valve
PROCEDURAL PROTOCOL

Protocolo de Diagnóstico de Taller Paso a Paso

STEP 1

Live Scan Tool Cylinder Balance Rate (SRC) Logging

Warm the engine until coolant temperature exceeds 80°C (176°F). Access scan tool live data for 'Cylinder Balancing / Smooth Running Control'. Observe the real-time fuel trim for all cylinders at stable idle (A/C off, transmission in park/neutral). Normal values are -1.5 to +1.5 mg/stroke. If Cylinder 3 reads +3.5 to +5.5 mg/stroke, the ECM is struggling to add massive fuel to compensate for a weak Cylinder 3 power stroke.

STEP 2

Automated Cylinder Cutout RPM Drop Test

Using scan tool bi-directional controls, perform an automated 'Cylinder Cutout Test'. The ECM will disable fuel injection to each cylinder sequentially. On a healthy cylinder, shutting off injection causes a sharp 45 to 65 RPM drop and noticeable engine stumble. If cutting out Cylinder 3 produces less than a 20 RPM drop, it proves Cylinder 3 was barely contributing power before being cut.

STEP 3

Individual Injector Backleak (Return Flow) Measurement

Disconnect the low-pressure fuel return line from all injectors. Attach graduated transparent test tubes to the return nipples. Start the engine and run at warm idle for exactly 2 minutes. Measure return volume in milliliters. A healthy injector returns less than 20-25 mL. If Cylinder 3 returns >40 mL, its internal hydraulic control valve seat is eroded, dumping rail pressure into the return.

STEP 4

Electronic Relative Compression & Mechanical Gauge Test

Execute an electronic 'Relative Compression Test' via scan tool, which monitors starter current draw across each compression stroke. All cylinders must match within 95% to 100%. If Cylinder 3 shows <85%, remove the glow plug and perform a physical mechanical compression gauge test (must exceed 22 bar with <3 bar variance). Low compression confirms a valve, ring, or head gasket issue.

STEP 5

Injector Cross-Swap Physical Verification

To conclusively isolate the injector from engine mechanics, remove the Cylinder 3 injector and swap it with Cylinder 1 (using new copper washers). Reprogram the respective IMA/QR codes into the ECM. Clear DTCs and road-test the vehicle. If the fault moves from P0269 to P0263 (Cylinder 1), the injector is 100% defective. If the fault stays on P0269 on Cylinder 3, the cause is mechanical compression or valvetrain wear.

STEP 6

IMA / QR Calibration Code Verification

Read the physical 6-to-30 digit alphanumeric code laser-etched onto the top plastic head of the Cylinder 3 injector. Compare this code against the code stored in the ECM memory using your scan tool. If an uncalibrated replacement injector was installed without programming, the ECM uses generic default pulse widths that can cause a 15% to 20% fueling error, triggering P0269.

COMPONENT-LEVEL REPAIR

Reparación de hardware y lista de piezas BOM

Cylinder 3 Fuel Metering Calibration & IMA Coding Architecture

Bosch CRI2 / CRI3 Solenoid Injector Assembly - Cylinder 3

0 445 110 369 / 0 445 116 059

High-precision electro-hydraulic fuel injector with laser-etched IMA calibration classification code

OEM: Protocol: Replace or recalibrate if backleak exceeds 35 mL/min or balance offset remains pegged at >±4.5 mg/stroke after coding
Heat-Treated Annealed Copper Injector Sealing Washer (1.5mm - 2.0mm)

F 00V C17 503 / OEM Copper Crush Washer

Gas-tight sealing ring preventing combustion gas leakage that drops effective cylinder compression

OEM: Protocol: Mandatory replacement whenever injector is removed
Injector Nozzle Micro-Orifice Tip Assembly (7-Hole)

DLLA 150 P 1828 / OEM Nozzle Assembly

Atomizes high-pressure diesel into micro-droplets; clogged micro-holes reduce cylinder contribution

OEM: Protocol: Replace if spray pattern testing shows distorted cone or missing spray plume
Workshop Technical & Economic Benchmark: Injector clamp stretch bolt: 7 Nm + 90° angle turn; Diagnostic scan tool capable of writing IMA/IQA 7-20 digit calibration strings; High-pressure fuel line torque: 28 - 32 Nm.
LIVE WORKSHOP TOOL

Calculadora interactiva de tolerancias Common Rail

IMA / IQA Injector Calibration Code & Checksum Validator

Validate the 7-to-20 character IMA string etched on the injector head. An incorrect character or wrong checksum causes the ECM to reject the code or default to an incorrect fuel trim curve, triggering P0269 contribution faults.

📐 Factory Engineering Tolerance: Allowable Smooth Running Trim: -1.5 to +1.5 mg/stroke
OEM REPLACEMENTS

Componentes de inyección asociados

Las siguientes bombas de combustible e inyectores common rail originales están verificados para motores con el código P0269. Verifique las presiones de trabajo antes del reemplazo:

Common Rail Injector

0445110369BOSCH

0445110369 Injector: VW 2.0 TDI EA189 CFFB CFHC Specs

View Technical Specs & Fitment →
Common Rail Injector

0445116024BOSCH

BOSCH 0445116024 Common Rail Piezo Injector for BMW N47 2.0d & N57 3.0d

View Technical Specs & Fitment →
Common Rail Injector

095000-5880Denso

095000-5880 Denso Toyota 2KD-FTV Injector: 23670-30050 Data

View Technical Specs & Fitment →
Common Rail Injector

28337917Delphi

28337917 Delphi Bobcat D24 Injector: 7030364 Specs & Data

View Technical Specs & Fitment →
Common Rail Injector

095000-8340Denso

095000-8340 Denso Mitsubishi 4D56 HP Injector: 1465A367 Data

View Technical Specs & Fitment →
Common Rail Injector

0445120289Bosch

0445120289 Bosch Perkins 1104D Injector: 2645A749 Data

View Technical Specs & Fitment →
CALIBRATION RELEARN

Reinicio de adaptación de bomba y ciclo de rodaje

Following replacement of the Cylinder 3 fuel injector, nozzle servicing, or valve adjustment, execute the adaptation routine:

1. Enter the new alphanumeric calibration code (IMA/QR code) stamped on the new Cylinder 3 injector into the ECM via scan tool.

2. Clear all stored trouble codes and confirm engine coolant temperature is above 75°C (167°F).

3. Access scan tool 'Engine Control Module' -> 'Special Functions' -> select 'Reset Cylinder Balance / Smooth Running Values'.

4. Start the engine and allow it to idle undisturbed in park/neutral for 5 minutes without touching any pedals, allowing the ECM to build initial torque offsets.

5. Accelerate vehicle smoothly in 4th gear to 80 km/h (2200 RPM), then release throttle completely to coast down in gear to 35 km/h (minimum 8s overrun).

6. Repeat this acceleration and coast-down sequence 5 times. Return to workshop and confirm Cylinder 3 balance rate is within ±1.5 mg/stroke.

DIFFERENTIAL DIAGNOSIS

Diagnóstico diferencial y códigos relacionados

P0303

Cylinder 3 Misfire Detected

Hard misfire code indicating complete lack of combustion on Cylinder 3, whereas P0269 indicates combustion occurs but with degraded power delivery.

P0203

Injector Circuit/Open - Cylinder 3

Electrical circuit fault code on Cylinder 3; if an injector wiring fault develops, P0203 will trigger alongside or override P0269.

P0263

Cylinder 1 Contribution/Balance Fault

Companion code on Cylinder 1; swapping injectors between Cylinders 3 and 1 allows immediate isolation of injector hardware vs cylinder mechanics.

FIELD REPAIR REPORTS

Casos reales de taller

CASE #1

2015 Ford Transit Custom 2.2 TDCi (Puma)(182,000 km)

Reported Complaint:Cold idle shake with mild combustion knock; DTC P0269 stored; Cylinder 3 balance trim pegged at +4.6 mg/stroke.
Teardown Root Cause:Dynamic backleak test: Cylinder 3 returned 62 mL in 2 minutes (Cylinders 1, 2, 4 returned 18-20 mL), confirming internal hydraulic valve erosion.
Repair Solution:Replaced internal control valve assembly on Cylinder 3 injector, generated new 16-character IMA code on test bench, and programmed into ECM. Cylinder 3 balance trim dropped to -0.1 mg/stroke with vibration eliminated.
DIAGNOSTIC FAQ

Preguntas técnicas frecuentes

¿Qué significa el código de fallo P0269?

El código de diagnóstico DTC P0269 indica que el módulo de control del motor (ECM/PCM) ha detectado que el cilindro 3 no entrega el impulso de par mecánico esperado hacia el cigüeñal, generando un desequilibrio de rotación intercilindros. En motores diésel de riel común, el ECM calcula continuamente el trabajo individual de cada cilindro monitoreando variaciones en el orden de submicrosegundos en la aceleración angular del cigüeñal mediante el sensor de posición del cigüeñal (CKP) durante la carrera de expansión/combustión, entre 30° - 90° después del punto muerto superior (ATDC). Si el algoritmo de control de marcha suave (SRC) / calibración de caudal cero (ZFC) del ECM debe aplicar una compensación de combustible excesiva (típicamente > +3.0 - +4.5 mg/embolada) para estabilizar el ralentí, o si la contribución del cilindro desciende entre 15% - 25% por debajo del promedio del motor, se registra el código P0269.

¿Cuáles son los síntomas más comunes de P0269?

Noticeable engine shudder, rough idle, and cabin vibration during warm idle (especially in Drive at traffic lights), Hesitation, flat spots, or rhythmic surging during light-to-moderate throttle cruising at 1200 to 2000 RPM, Check Engine Light (MIL) illuminated, occasionally accompanied by flashing glow plug light or traction control warning, Heavy puffing of grey or black exhaust smoke on sudden acceleration due to unburned fuel in Cylinder 3, Elevated fuel consumption and rough engine shutdown (excessive diesel shudder when turning off the ignition), Scan tool live data displays Cylinder 3 balance rate pegged at high positive compensation (+3.5 to +5.5 mg/stroke).

¿Qué causa P0269 en un motor diésel?

Partially clogged, carbon-coked, or eroded spray holes in the Cylinder 3 fuel injector nozzle tip; Excessive internal control valve wear (backleak) in Cylinder 3 injector, reducing effective injection pressure and fuel delivery; Incorrect, corrupted, or uncalibrated IMA / QR injector calibration code programmed into the ECM for Cylinder 3; Low mechanical cylinder compression on Cylinder 3 caused by worn piston rings, valve seat recession, or blown head gasket; Cylinder 3 glow plug tip coated in thick carbon or burned out, impairing post-start combustion stability in cold engines; Worn camshaft lobe or collapsed hydraulic lifter reducing intake valve lift and starving Cylinder 3 of fresh air charge.

¿Es seguro conducir con el código P0269 activo?

🟡 Precaución: Modo emergencia activo / Acudir a taller

¿Cuánto cuesta reparar el código de avería P0269?

Los costes habituales de reparación para P0269 dependen de la causa raíz identificada en el diagnóstico: Nivel 1 (Mantenimiento menor / DIY): 40 € - 110 €: Limpieza química del sistema de combustible y sustitución del filtro (Limpieza de sensor, cambio de filtro de combustible, revisión de fusibles o conectores.); Nivel 2 (Sustitución de componente): 180 € - 480 €: Sustitución del inyector del cilindro 3 por recambio original (Sustitución de componente individual (válvula reguladora, unidad dosificadora o inyector reconstruido).); Nivel 3 (Subconjunto mayor): 850 € - 2.200 €: Revisión de la compresión mecánica del motor o trabajos en la culata (Revisión de bomba de alta presión, juego de inyectores nuevos o sustitución del conjunto DPF.). Tarifas de referencia de talleres. Más del 70% de las incidencias se resuelven en Nivel 1 o 2 sin sustituir subconjuntos completos.

Can a fuel additive or injector cleaner fix trouble code P0269?

In mild, early-stage cases where P0269 is caused by soft gummy diesel varnish or light carbon deposits on the injector nozzle spray holes, a professional-grade polyetheramine (PEA) or cetane-boosting diesel injector cleaner run through a concentrated dose can dissolve deposits and restore balance rates within 50 to 100 miles. However, if the cause is mechanical control valve erosion (excessive backleak) or low mechanical cylinder compression, chemical additives will have zero effect and the injector must be replaced.

Why does the scan tool show positive fuel trim (+4.0 mg/stroke) for a weak cylinder?

In common rail diesel ECM software, the cylinder balance trim represents COMPENSATION. If Cylinder 3 is weak (delivering less power than the other cylinders), the engine idle would shake and slow down. To prevent this, the ECM's Smooth Running Control algorithm adds EXTRA fuel (positive trim, such as +4.0 mg/stroke) to Cylinder 3 to prop up its power stroke and match the other cylinders. A high positive number means the cylinder is weak.

Is trouble code P0269 safe to drive with?

You can drive short distances to reach a repair facility, but prolonged driving is not recommended. If the contribution fault is caused by an injector nozzle with a bad spray pattern (dripping rather than atomizing), liquid diesel will pool on the piston crown, risking severe piston melting and engine failure under highway loads. Furthermore, incomplete combustion creates high soot levels that will rapidly clog your DPF filter.