All codes
P0201Fuel System
Injector Circuit Malfunction Cylinder 1
Diagnose P0201 fuel injector circuit fault on cylinder 1 - wiring, driver, and injector causes plus fixes.
What you may notice
Symptoms
- 01Check engine light on
- 02Misfire or rough running on cylinder 1
- 03Rough idle
- 04Reduced power
- 05Possible hesitation on acceleration
Where to look first
Common causes
- 01Faulty fuel injector on cylinder 1
- 02Damaged or corroded injector wiring/connector
- 03Failed injector driver in the ECM
- 04Blown fuse or damaged relay for injector circuit
- 05Water intrusion at the injector connector
Step by step
What to check and repair
- 01Inspect injector wiring and connector for damage or corrosion
- 02Test injector resistance against manufacturer spec
- 03Swap with a known-good injector to isolate the fault
- 04Check the injector fuse and relay
- 05Have the ECM injector driver circuit tested if wiring is good
What Does P0201 Mean?
P0201 indicates an electrical fault in the fuel injector circuit for cylinder 1 - the ECM detected an open circuit, short, or a signal outside the expected range when it tried to command that injector.
Electrical, Not (Usually) Mechanical
Unlike a clogged injector, P0201 is normally about the circuit itself: wiring, connector, or the injector's internal coil, rather than a fuel delivery/flow problem.
How AI4Car Helps
AI4Car highlights which injector circuit is flagged and lets you log whether the fault is constant or intermittent, which is a strong clue toward a wiring issue versus a failed injector.