P0262 - Cylinder 1 Fuel Injector
System
Powertrain (Engine & Gearbox)
Technical Description
The control module has detected a fault in the Cylinder 1 Fuel Injector (P0262). The signal is above the upper threshold, typically from an open circuit, poor connection, or a short to battery voltage. The fault is isolated to cylinder 1, positioned closest to timing drive (reference cylinder). This directly impacts individual cylinder volumetric efficiency, firing synchronization, and dedicated harness branch loading.
Multimeter Test Points & Nominal Values
| Test Point / Component | Measurement | Nominal Target Range | Test Condition |
|---|---|---|---|
| Cylinder 1 Injector – Coil Resistance | Resistance (Ω) | 11.5 - 15.5 Ω (port) / 0.5 - 3.0 Ω (direct injection) | Connector disconnected at 20°C (cylinder 1) |
| Cylinder 1 Injector – Injection Pulse at 0° crank angle | Signal (ms) | 2.5 - 4.5 ms idle / 1.5 - 20 ms under load | Engine running |
| Cylinder 1 Injector – Supply Voltage | Voltage (V) | 11.8 - 14.4 V (port) / up to 65 - 90 V boost (direct) | Ignition ON / engine running |
Connector disconnected at 20°C (cylinder 1)
Engine running
Ignition ON / engine running
Oscilloscope Waveform Analysis
1 ms/div, 20 V/divPossible Causes
Open circuit on signal wire, spread terminal pin, or short to power feed at Cylinder 1 Fuel Injector
Timing drive harmonic zone (cylinder 1): Front reference cylinder exposed to cyclic vibrations from timing belt or chain drive and oil mist from front crank seal.
Plenum entry intake pulse:Cooler incoming charge air at the front manifold runner creates cold-start localized lean transients on cylinder 1.
Channel A:Verify dedicated wiring pins and signal pair for circuit A against the schematic.
Chafed or pinched wiring harness along the signal path to Cylinder 1 Fuel Injector
Internal mechanical wear or carbon deposits inside Cylinder 1 Fuel Injector
Defective internal output driver or reference circuit in the control module for Cylinder 1 Fuel Injector
Symptoms
5
Recommended Solution
Compare signal voltage and resistance between circuit A and companion circuit B at module connector.
Swap component on cylinder 1 over to cylinder 2 and clear DTCs to confirm if the fault follows the part.
Inspect front timing cover wiring harness routing for mechanical rubbing against accessory belt tensioner pulleys.
Measure signal terminal voltage with ignition ON and sensor unplugged to determine if ECM pull-up is active or harness is shorted to 12V.
Verify loaded supply voltage and harness terminal pins at Cylinder 1 Fuel Injector.
Check circuit continuity and ground-side voltage drop (< 0.05 V) for Cylinder 1 Fuel Injector.
Perform fuel rail pressure-drop / balance test to identify leaking, stuck, or clogged injectors.
Mechanic's Tip
Pro-tip for cylinder 1: Cylinder 1 is the primary sync reference. Always scope cam and crank phase correlation if the DTC recurs after replacing the component.