OBD-II DIESEL WERKPLAATSPROTOCOL8-10 min read
P0262Brandstof & RaildrukHoge Ernst💡 Motorstoringslampje brandt⚠️ Noodloop actief

P0262: Verstuivercircuit cilinder 1 - Spanning te hoog

Foutcode (DTC) P0262 geeft aan dat het motorregelapparaat (ECU) heeft gedetecteerd dat de elektrische spanning in het aanstuurcircuit van de verstuiver voor cilinder 1 de gekalibreerde bovengrens heeft overschreden, of dat het low-side stuurcircuit kortgesloten is met een positieve spanningsbron (zoals de 12V-boordspanning of de 80V-200V boostrail van de condensator). Onder normale omstandigheden wordt de low-side stuurleiding uitsluitend tijdens de inspuitcyclus naar massa geschakeld; in rusttoestand wordt de spanning begrensd door een intern pull-up circuit. Als deze leiding contact maakt met een continue voedingsspanning, of wanneer de interne blusdiode faalt, wordt P0262 opgeslagen en wordt de inspuiting op cilinder 1 uitgeschakeld.

🚗 BESTUURDERSGIDS & REPARATIEPROTOCOL

🚗 Rijveiligheid, geschatte reparatiekosten & verificatie

🔴 Kritiek: Stop rijden / Takelwagen vereist
  1. 01

    🚦 Rijveiligheid en mechanisch risico

    Directe inspectie en noodzaak voor een takelwagen

    Verstuivercircuit cilinder 1 hoog - Continue hoogspanningskortsluiting of geblokkeerde eindtrap

    Het verstuivercircuit van cilinder 1 detecteert een abnormaal hoge spanning (kortsluiting naar accu of interne boost-rail). Dit kan ertoe leiden dat de verstuiver continu mechanisch open blijft staan, met waterslag (hydrolock) als gevolg.

    MECHANISCHE RISICO'S BIJ DOORRIJDEN:Een openblijvende verstuiver kan de zuigerbodem doen smelten, drijfstangen verbuigen of een op hol geslagen dieselmotor (diesel runaway) veroorzaken.
  2. 02

    💰 Typisch werkplaatsbudget

    Verwachte kostenstaffels voor onderdelen en arbeid
    Klein onderhoud / Filter€ 45 - € 110 (Inspectie en reparatie van kortsluiting naar plus in de kabelboom)

    Sensorreiniging, brandstoffilter vervangen, zekering controleren of contacten reinigen.

    Klep / Sensor vervangen€ 240 - € 550 (Vervanging van defecte verstuiver cilinder 1)

    Vervanging enkel onderdeel (drukregelventiel, doseereenheid of gereviseerde verstuiver).

    Grote revisie / Pomp en injectoren€ 850 - € 2.200 (Vervanging van ECU-hoofdprintplaat of demontage van de motor bij waterslagschade)

    Revisie hogedrukpomp, nieuwe OEM-verstuivers of vervanging DPF-roetfilter.

    Werkplaatsreferentietarieven. Meer dan 70% van de gevallen wordt opgelost binnen niveau 1 of 2 zonder vervanging van complete subeenheden.

  3. 03

    🧰 Snelle visuele controle zonder gereedschap

    5-minuten garagecheck voordat u de werkplaats belt
    11. Controleer direct het motoroliepeil: Als het oliepeil stijgt of sterk naar diesel ruikt, start de motor dan absoluut niet (openstaande verstuiver).
    22. Koppel verstuiver 1 los en controleer bij contact AAN (motor uit) of de kortsluiting naar plus aanwezig blijft op de kabelboomstekker.
    33. Inspecteer de kabelboom bij het hitteschild van de uitlaat op gesmolten isolatie waardoor draden met elkaar in contact komen.
  4. 04

    🛡️ Bescherming tegen verkeerde diagnoses

    Gerichte vragen aan de monteur om onnodige vervanging te voorkomen
    ""Controleer het oliepeil op de peilstok en inspecteer de cilinder met een endoscoop voordat herhaaldelijk wordt geprobeerd te starten.""
    ""Meet de spanning op de signaaldraad van de verstuiver bij contact AAN; hier mag geen continue 12V of 80V aanwezig zijn zonder actieve stuurpuls.""
    ""Laat een compressietest uitvoeren als de cilinder vol diesel heeft gestaan om te controleren of de drijfstang niet is verbogen.""

    Technische opmerking: Stel deze gerichte vragen aan uw monteur voordat u akkoord gaat met dure reparaties:

🔧 PROFESSIONEEL TECHNICUSADVIES & REPARATIEPROTOCOLRAPID ASSESSMENT

30-seconden werkplaatstriage

Belangrijkste symptomen
  • Violent engine shaking, severe shudder, and continuous single-cylinder misfire under all operating conditions
  • Significant loss of vehicle acceleration, sluggish throttle response, and inability to maintain highway cruising speeds
  • Illuminated Check Engine Light (MIL) accompanied by flashing glow plug warning light and ESP/traction warning
Meest waarschijnlijke oorzaken
  • Cylinder 1 injector control wire shorted to 12V battery power or an adjacent energized wire in the wiring harness loom
  • Cylinder 1 injector high-side driver wire shorted to an un-switched 12V power supply due to harness melted insulation
  • Internal short circuit inside the Cylinder 1 fuel injector coil winding bridging power to the control terminal
Eerste vereiste actie

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

❌ Veelvoorkomende werkplaatsmisvatting:

P0262 proves the engine control module (ECM) internal driver stage has blown and the ECM must be replaced and reprogrammed ($1,500 - $2,800).

🔍 Technische en hydraulische werkelijkheid:

P0262 indicates that the Cylinder 1 injector low-side control wire is shorted to battery positive voltage (+12V or +80V boost rail), or the internal solenoid coil resistance has open-circuited. The ECM's diagnostic driver senses that the voltage does not drop to near-zero when the driver transistor turns ON. In over 80% of verified cases, the ECM is completely unharmed. The true culprit is a broken internal solenoid coil bonding wire inside the injector head (reading OL infinity on a multimeter) or a pinched wire harness shorting against an adjacent +12V power supply wire.

💡 Technisch verificatieprotocol:

Unnecessarily condemning a $2,000 ECM vs measuring coil resistance with a $20 multimeter to pinpoint an open injector coil ($180 rebuild) or repairing pinched wiring ($15), saving over $1,800.

Severe Injector Latch-Open Hydro-Lock & Piston Torching Hazard

CRITICAL WORKSHOP WARNING: Code P0262 represents an immediate mechanical threat to the engine! When an injector circuit is shorted to power, the electromagnetic solenoid can latch wide open. Because common rail fuel pressure exceeds 1800 bar, an open injector discharges vast quantities of raw diesel fuel into Cylinder 1 even while cranking.

MANDATORY PROTOCOL: If the cylinder fills with liquid diesel, the engine will suffer hydraulic lock (Hydro-Lock) upon the next compression stroke, instantly bending the connecting rod, snapping the piston wrist pin, or blowing a hole through the cylinder block. If P0262 is present, remove the Cylinder 1 glow plug and inspect for liquid diesel fuel ejection before attempting any diagnostic starter cranking!

PLATFORM ARCHITECTURE

Meest getroffen motoren en injectieplatformen

Deze foutcode treedt hoofdzakelijk op bij de volgende common-rail dieselplatforms. Raadpleeg hieronder uw motorfamilie voor fabrieksspecificaties en onderdeelnummers:

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

Bosch EDC17 Common Rail System

Bekende fabriekszwakte: Piezo stack degradation, injector harness terminal fretting, DPF differential pressure sensor silicone tube split.

Belangrijk onderdeel:03L130277, 0445110369, 076906051A

Mercedes-Benz 2.1 CDI (OM651 / OM646)

Delphi CRD2 / Bosch Common Rail Injection

Bekende fabriekszwakte: Delphi piezo to solenoid conversion wiring harness chafing, differential pressure sensor internal diaphragm drift.

Belangrijk onderdeel:A6510704987, A6510700587, A0061539528

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

Bosch CRI2.5 / CRI3.0 Common Rail

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

Belangrijk onderdeel:13537805428, 0445116024, 12217801201

Ford 6.7L Powerstroke V8 Diesel

Bosch CP4.2 High-Pressure Common Rail System

Bekende fabriekszwakte: EGR cooler carbon clogging, DEF injector white crust crystallization, fuel volume control valve harness chafing.

Belangrijk onderdeel:BC3Z-9A543-A, FC3Z-9F593-B, BC3Z-5J281-A
WORKSHOP MASTER TEARDOWN GUIDE

P0201-P0204 Injector Circuit Diagnosis Guide

Workshop troubleshooting guide for OBD-II codes P0201 to P0204 (Cylinder 1-4 Injector Circuit Malfunction). Resistance test specs, harness checks, and ECU driver stage.

Read Full Master Guide →
THEORY OF OPERATION

Stuurstroomcircuit & Actuatorlogica

1. Dynamic In-Demand Fuel Metering

Common rail diesel fuel injectors are driven by a sophisticated dual-switch topology inside the ECM: a shared high-side power MOSFET and an individual low-side ground-switching MOSFET. The injector coil is energized by high voltage (80V-90V solenoid, 140V-200V piezo). During normal operation, when the low-side driver opens at the end of injection, an inductive voltage spike of ~50V is generated and clamped by an internal freewheeling diode. If the low-side wire is physically shorted to constant 12V battery voltage or another energized circuit in the wiring loom, the ECM registers a continuous high-voltage condition.

2. Closed-Loop PID Deviation Monitoring

The ECM performs continuous hardware monitoring of the Cylinder 1 driver stage. If the low-side driver terminal measures constant battery voltage (>11.5 V) when the driver is commanded to pull to ground, or if voltage remains higher than calibrated diagnostic thresholds during the Key-ON static test window, DTC P0262 is flagged. To prevent the short-circuit voltage from back-feeding into the ECM internal logic boards, the ECM disables firing pulses to Cylinder 1 and initiates Limp-Home Mode.

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

Continuous High-Voltage Short vs Latching Injector Hazard: If the Cylinder 1 injector circuit is shorted to a positive voltage feed while the ground side is also compromised, the solenoid coil can become continuously energized (100% duty cycle). In a diesel engine, an injector held continuously open dumps 1800 bar fuel directly into the cylinder. Within seconds, this causes hydraulic cylinder lock (Hydro-Lock) or severe piston melting. If code P0262 is detected, NEVER crank the engine until wiring harness continuity to 12V is completely isolated!

ENGINEERING SPECIFICATIONS

Elektrische & Hydraulische referentiewaarden

Solenoid Coil DC ResistanceSolenoid Injector Coil: 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 terminal pins and cylinder head metal chassis (tested with 250V/500V insulation tester)Between terminals and pump body (ground)
Operating Supply VoltageECM Internal Boost Voltage: 80 V - 90 V DC (Solenoid) or 140 V - 200 V DC (Piezo); Battery supply to ECM: > 12.0 VHigh-side feed from ECM / main relay
PWM Frequency StandardGround-switched PWM high-speed driver; Slew rate rise time < 50 µs; Clamped inductive spike ~45 V - 55 VSquare-wave PWM modulation
Idle Duty Cycle (Warm Engine)Cylinder 1 Smooth Running Balance Offset (SRC): Nominal -1.5 to +1.5 mg/stroke (exceeding ±3.5 mg/stroke flags imbalance)Nominal baseline at 250–350 bar
Full-Load Duty Cycle (WOT)High-Voltage Short Circuit Trip Threshold: Low-side driver voltage remains > 11.0 V during commanded firing windowMaximum high-speed fuel delivery demand
Low-Pressure Feed SupplySystem Feed: +3.5 to +5.5 bar (electric in-tank pump) / < 0.2 bar vacuum (mechanical); Harness Line Resistance: < 0.4 Ω end-to-end between ECM pin and Cylinder 1 injector connectorMeasured at pump fuel inlet
Internal Cascade BackpressureInsulation Resistance Trip Limit: Resistance between injector power line and 12V harness feeds must be infinite (OL)Controlled by overflow cascade valve
PROCEDURAL PROTOCOL

Stap-voor-stap Werkplaatsprotocol

STEP 1

Unplug Diagnostic Flip Test (Isolating Harness vs Injector)

Turn the ignition Key-ON with the engine stopped. Clear stored trouble codes. Unplug the electrical connector from the Cylinder 1 fuel injector while monitoring live scan tool codes. If code P0262 immediately clears and transforms into P0201 (Cylinder 1 Circuit Open), the wiring harness and ECM driver are 100% HEALTHY-the injector itself has an internal short circuit! If P0262 persists with the injector completely disconnected, the wiring harness is shorted to a power source.

STEP 2

Harness Short-to-Voltage Multimeter Audit (Key-ON Engine-OFF)

With the Cylinder 1 injector disconnected and Key-ON, measure DC voltage on both pins of the harness connector to engine battery negative. Pin 1 (High-Side Feed) should read 0.0V (or a low floating diagnostic voltage <3.0V when un-energized). Pin 2 (Low-Side Control) should read floating voltage <2.0V. If either pin reads a solid 12.0V-14.0V battery voltage with the engine stopped, that wire is shorted to a 12V power wire inside the engine harness conduit.

STEP 3

Precision Four-Wire Low-Resistance Coil Measurement

Using a milliohm meter or digital multimeter with lead-zeroing on the lowest ohms scale, measure resistance across the two pins of the Cylinder 1 injector: normal resistance for solenoid injectors is 0.20 Ω to 0.45 Ω @ 20°C; for piezo injectors, 180 kΩ to 220 kΩ. A reading of 0.0 Ω (dead short) or abnormal high resistance (>2.0 Ω on solenoid) confirms internal coil winding breakdown.

STEP 4

Harness Continuity & Wire-to-Wire Short Circuit Test

Turn Key-OFF, disconnect battery, and unplug the ECM main harness connector. Using a multimeter on ohms scale, measure resistance between the Cylinder 1 injector wires and all other pins in the engine harness connector. Resistance must be infinite (OL). If any measurable continuity (<100 kΩ) exists to another circuit, trace the harness for melted conduit caused by contact with the exhaust or turbo.

STEP 5

Connector Water Ingress & Terminal Arcing Inspection

Inspect the female terminal cavities of the Cylinder 1 connector for black arcing soot or green copper corrosion. Water or conductive road salt ingress can bridge the high-voltage supply pin across the plastic housing into the low-side pin, creating an artificial P0262 short-to-power condition.

STEP 6

Oscilloscope Waveform & Inductive Clamping Verification

Reconnect the injector and back-probe the low-side control wire with an oscilloscope. Crank the engine: verify that the low-side driver pulls the signal cleanly to ground during firing and releases cleanly with a sharp inductive flyback voltage peak clamped at ~45V-55V. If the voltage remains pinned at 12V or fails to switch, the ECM low-side driver transistor is internally shorted.

COMPONENT-LEVEL REPAIR

Reparatie op hardwareniveau & Onderdelenlijst

Cylinder 1 Common Rail Injector Drive & Wiring Subsystem

Bosch CRI2 / CRI3 Solenoid Injector Assembly - Cylinder 1

0 445 110 369 / 0 445 116 059

High-speed electro-hydraulic fuel injector with calibrated pilot/main injection metering

OEM: Protocol: Replace if internal solenoid coil is open circuit (infinite resistance) or shorted to +12V
High-Temperature 2-Pin Injector Connector Repair Kit with Silicone Boots

1 928 498 056 / Tyco Junior Timer 2-Way

Provides positive terminal spring tension to withstand 150V injection pulse vibrations

OEM: Protocol: Replace if pin drag test feels loose (< 1.5N retention force) or locking latch is broken
Rocker Cover Internal Injector Sub-Harness (Under-Valve-Cover Loom)

OEM Oil-Resistant Wiring Loom (Make-specific)

Prevents 130°C hot engine oil from degrading wire insulation

OEM: Protocol: Replace if internal wires are brittle or oil has wicked into terminal pins
Workshop Technical & Economic Benchmark: Digital multimeter (0.01 ohm resolution); Injector terminal de-pinning tool kit; Injector clamp stretch bolt: engine specific (e.g. 8 Nm + 90°).
LIVE WORKSHOP TOOL

Interactieve Common Rail Tolerantiecalculator

Injector Solenoid & Piezo Resistance Inspector

Disconnect Cylinder 1 plug. Measure resistance directly across the 2 injector pins. Solenoid injectors MUST measure 0.25 - 0.45 ohms at 20°C. If reading OL (infinity), the coil winding has blown open.

📐 Factory Engineering Tolerance: Good Solenoid Coil Resistance: 0.25 - 0.45 Ohms
OEM REPLACEMENTS

Bijbehorende brandstofinjectieonderdelen

The following genuine OEM fuel pumps and common rail injectors are verified factory equipment for engines reporting fault protocol P0262. Cross-reference operating pressures and tightening torques before sub-assembly replacement:

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

Pomp-adaptatiereset & Inleer-proefrit

Following replacement of the Cylinder 1 fuel injector or repair of the shorted wiring harness, execute the calibration routine:

1. Enter the new 6-to-30 digit alphanumeric calibration code (IMA / QR code) stamped on the top of the new Cylinder 1 injector into the ECM via scan tool.

2. Clear all stored trouble codes and ensure battery voltage is fully charged (>12.5 V).

3. Access scan tool 'Engine Control Module' -> 'Special Functions' -> select 'Reset Injector Driver Stage Fault Memory'.

4. Start the engine and let it idle at full operating temperature (coolant >80°C) for 5 minutes without touching the accelerator.

5. The ECM will perform smooth-running control (SRC) zero-fuel calibration cycles to re-balance cylinder torque.

6. Conduct a 15-minute road test through all gear ranges, verifying smooth idle, instant throttle response, and zero pending DTCs.

DIFFERENTIAL DIAGNOSIS

Differentiaaldiagnose & Gerelateerde fouten

P0201

Injector Circuit/Open - Cylinder 1

Companion open-circuit fault on Cylinder 1; unplugging a shorted injector will transform P0262 into P0201, confirming the injector is bad.

P0261

Cylinder 1 Injector Circuit Low

Opposite electrical failure: occurs when the injector control wire is shorted to vehicle chassis ground rather than to a positive voltage source.

P0301

Cylinder 1 Misfire Detected

Direct mechanical consequence: because the ECM disables the Cylinder 1 injector driver, Cylinder 1 fails to fire, setting misfire code P0301.

FIELD REPAIR REPORTS

Praktijkgevallen uit de werkplaats

CASE #1

2014 Mercedes-Benz C250 CDI (W204 OM651 Delphi)(178,000 km)

Reported Complaint:Sudden crank-no-start condition with red dashboard warning; solitary code P0262 stored in ECU.
Teardown Root Cause:Multimeter resistance test on Cylinder 1 Delphi injector pins read OL (open circuit infinity), while Cylinders 2, 3, 4 read 0.36 Ohms. Disconnecting Cylinder 1 plug allowed the engine to start immediately on 3 cylinders.
Repair Solution:Replaced defective Cylinder 1 Delphi injector. The ECU power stage unlatched from protective shutdown and engine ran smoothly with P0262 cleared.
DIAGNOSTIC FAQ

Veelgestelde technische vragen

Wat betekent motorfoutcode P0262?

Foutcode (DTC) P0262 geeft aan dat het motorregelapparaat (ECU) heeft gedetecteerd dat de elektrische spanning in het aanstuurcircuit van de verstuiver voor cilinder 1 de gekalibreerde bovengrens heeft overschreden, of dat het low-side stuurcircuit kortgesloten is met een positieve spanningsbron (zoals de 12V-boordspanning of de 80V-200V boostrail van de condensator). Onder normale omstandigheden wordt de low-side stuurleiding uitsluitend tijdens de inspuitcyclus naar massa geschakeld; in rusttoestand wordt de spanning begrensd door een intern pull-up circuit. Als deze leiding contact maakt met een continue voedingsspanning, of wanneer de interne blusdiode faalt, wordt P0262 opgeslagen en wordt de inspuiting op cilinder 1 uitgeschakeld.

Wat zijn de meest voorkomende symptomen van P0262?

Violent engine shaking, severe shudder, and continuous single-cylinder misfire under all operating conditions, Significant loss of vehicle acceleration, sluggish throttle response, and inability to maintain highway cruising speeds, Illuminated Check Engine Light (MIL) accompanied by flashing glow plug warning light and ESP/traction warning, Heavy puffing of white, grey, or black unburned diesel smoke from exhaust pipe during starting and acceleration, Strong, pungent odor of raw diesel fuel surrounding the vehicle exhaust and engine bay, Diagnostic scan tool live data shows Cylinder 1 contribution balance pegged at maximum positive fuel trim (+4.5 to +6.0 mg/stroke).

Wat veroorzaakt P0262 bij een dieselmotor?

Cylinder 1 injector control wire shorted to 12V battery power or an adjacent energized wire in the wiring harness loom; Cylinder 1 injector high-side driver wire shorted to an un-switched 12V power supply due to harness melted insulation; Internal short circuit inside the Cylinder 1 fuel injector coil winding bridging power to the control terminal; Damaged, shorted, or blown output driver MOSFET transistor inside the Engine Control Module (ECM); Water, engine oil, or road salt contamination inside the main engine wiring bulkhead connector bridging 12V to the injector pin; Aftermarket performance tuning box or piggyback wiring harness shorting internal injector driver tracks.

Is het veilig om te rijden met actieve code P0262?

🟡 Pas op: Noodloop actief / Bezoek werkplaats

Wat kost het repareren van foutcode P0262?

De gemiddelde reparatiekosten voor storingscode P0262 hangen af van de exacte oorzaak en het diagnoseniveau: Niveau 1 (Klein onderhoud / Doe-het-zelf): € 45 - € 110 (Inspectie en reparatie van kortsluiting naar plus in de kabelboom) (Sensorreiniging, brandstoffilter vervangen, zekering controleren of contacten reinigen.); Niveau 2 (Vervanging onderdeel): € 240 - € 550 (Vervanging van defecte verstuiver cilinder 1) (Vervanging enkel onderdeel (drukregelventiel, doseereenheid of gereviseerde verstuiver).); Niveau 3 (Revisie hoofdsysteem): € 850 - € 2.200 (Vervanging van ECU-hoofdprintplaat of demontage van de motor bij waterslagschade) (Revisie hogedrukpomp, nieuwe OEM-verstuivers of vervanging DPF-roetfilter.). Werkplaatsreferentietarieven. Meer dan 70% van de gevallen wordt opgelost binnen niveau 1 of 2 zonder vervanging van complete subeenheden.

What does 'Circuit High' mean on a fuel injector circuit?

In an injector circuit, 'Circuit High' means the ECM has detected voltage on the low-side control wire that is higher than it should be. Normally, this wire is either floating at a low diagnostic voltage or pulled to ground (0V) to fire the injector. If this wire contacts 12V battery power or high voltage from another circuit in the harness, the ECM flags code P0262.

Can code P0262 cause the engine to hydro-lock?

Yes, in severe failure modes where the injector coil is shorted to power while the ground side is completed, the injector can be held continuously energized (wide open). Because the common rail stores diesel at 1800 bar, the injector will pump liquid diesel into Cylinder 1 at high volume. If the cylinder fills with liquid diesel, the engine will suffer hydraulic lock upon cranking, bending connecting rods and destroying the engine.

How do I diagnose whether P0262 is caused by a bad injector or bad wiring?

Unplug the Cylinder 1 injector connector. Turn Key-ON and check the diagnostic codes with your scan tool. If P0262 disappears and changes to P0201 (Injector Circuit Open), the wiring harness and ECM are 100% fine; the short was inside the injector coil, and replacing the injector will fix the vehicle. If P0262 remains active with the injector completely unplugged, the wiring harness wire is shorted to a 12V power line.