BMW P0201: Injector Circuit/Open Cylinder 1 — Diagnosis and Repair

P0201 means Injector Circuit/Open Cylinder 1. The DME records it when DME detects an open or invalid electrical response at injector 1; diagnosis must separate an electrical signal fault from a real system fault. Use OBDThink to preserve the recording module and freeze frame for P0201, then test cylinder 1 fuel-injector power and DME control circuit without guessing or swapping parts. What Does P0201 Mean? This standardized powertrain DTC concerns cylinder 1 fuel-injector power and DME control circuit. On BMW vehicles the exact test plan and component layout vary by engine, chassis and DME software, so verify the VIN in BMW service information. The decisive clue is not the code alone: DME detects an open or invalid electrical response at injector 1. Compare commanded behavior with the measured signal before condemning a component. Code: P0201 Definition: Injector Circuit/Open Cylinder 1 Module: DME (gasoline) or DDE where applicable Key evidence: DME detects an open or invalid electrical response at injector 1 Typical causes: unseated injector plug, broken control wire, open injector winding, supply fault, pin damage, or DME output-stage fault Severity: diagnose promptly Note: confirm engine and wiring variant by VIN First preserve the freeze frame. If DME detects an open or invalid electrical response at injector 1, inspect cylinder 1 fuel-injector power and DME control circuit and its supporting system in the same operating condition. Symptoms • Injector Circuit/Open Cylinder 1 commonly appears with hard starting, hesitation during acceleration, rail-pressure oscillation and limp mode. • The freeze frame may show the fault while DME detects an open or invalid electrical response at injector 1, which is more useful than the warning lamp alone. • Target and actual values separate a persistent defect from an intermittent connector or harness interruption. • A companion fault from the same module may identify whether cylinder 1 fuel-injector power and DME control circuit is the cause or a consequence. Possible Causes Start with accessible circuit and connection checks, then prove the sensor or actuator, and leave expensive mechanical work until last. • Low cost: inspect the connector, terminal tension, contamination and the harness around cylinder 1 fuel-injector power and DME control circuit. • Low cost: check hoses, ducts, grounds, fuses and supply paths that directly affect cylinder 1 fuel-injector power and DME control circuit. • Medium cost: test the named sensor or actuator dynamically; the defining evidence is that DME detects an open or invalid electrical response at injector 1. • Medium cost: correct the system condition rather than masking it; likely branches include unseated injector plug, broken control wire, open injector winding, supply fault, pin damage, or DME output-stage fault. • High cost: only after circuit and mechanical evidence, consider control-unit repair or major mechanical work using VIN-specific BMW service data. Diagnosis Steps with OBDThink OBDThink is an independent BMW coding and diagnostic mobile app and is not affiliated with BMW AG. Available live data and freeze frame detail depend on the vehicle, adapter and module. • 1. Scan every control unit with OBDThink; save P0201, the recording DME, status, frequency and freeze frame before clearing anything. • 2. Reproduce the recorded operating condition safely and graph target versus actual values. Compare low-side supply and rail target/actual data; inspect the sensor connector, pump supply and pressure-control hardware. • 3. With ignition safely isolated where required, inspect and electrically test cylinder 1 fuel-injector power and DME control circuit; load-test power and ground rather than relying on continuity alone. • 4. Separate circuit from mechanism: manipulate the harness while monitoring data, then perform the relevant smoke, vacuum, pressure, airflow or waveform test. • 5. Confirm the repair by clearing the code, completing a cold start and controlled drive cycle, and rescanning all related modules. IF DME detects an open or invalid electrical response at injector 1 AND wiring/load test fails -> repair the circuit ELSE IF command is correct but mechanism does not respond -> test cylinder 1 fuel-injector power and DME control circuit ELSE compare companion faults and BMW VIN-specific test plan THEN clear, drive, and rescan The fastest distinction is to watch the relevant command and actual value while testing cylinder 1 fuel-injector power and DME control circuit; a fixed signal and a responding mechanism point in different directions. Repair • Low cost: Begin at cylinder 1 fuel-injector power and DME control circuit: reseat its plug, check terminal tension and repair heat, oil, water or abrasion damage found on that exact route. • Medium cost: Use the recorded evidence—DME detects an open or invalid electrical response at injector 1—to repair the confirmed branch among unseated injector plug, broken control wire, open injector winding, supply fault, pin damage, or DME output-stage fault, then retest before adaptations are reset. • Medium cost: Fit a replacement sensor or actuator in cylinder 1 fuel-injector power and DME control circuit only after a dynamic comparison proves the old unit cannot follow the DME command. • High cost: Reserve DME repair or invasive mechanical work for a failed BMW service test after supply, ground, signal and physical operation all pass. After repair, verify that DME detects an open or invalid electrical response at injector 1 no longer occurs, readiness can complete, and P0201 does not return as pending or confirmed. Can You Drive with P0201? Avoid heavy load. Stop if the engine stalls, fuel leaks, or rail pressure becomes unstable. Treat P0201 as measured evidence, not a parts order. A saved freeze frame, a target/actual comparison and a load-tested circuit usually reveal the least expensive correct repair.