# P0201: Injector Circuit/Open - Cylinder 1 **Verdict:** Drive to a shop this week Fuel and air metering - Generic OBD-II code, applies to all gasoline cars and light trucks sold in the US since 1996. - **Typical cost:** $100-$1,100 - **Urgency:** This week - **Most likely:** Failed injector coil or broken wiring - **DIY?:** Steps 1-3 ## Quick answer P0201 means the engine computer has detected an open or faulty electrical circuit for the fuel injector on cylinder 1. If the injector cannot be switched on, cylinder 1 gets no fuel and misfires, so the engine usually runs rough. A broken injector coil, a damaged connector or wire, or a lost power feed are the common causes. ## What does P0201 mean? Each fuel injector is an electrically operated valve. On most port-injected engines, the injector receives 12 volts through a fuse or relay, and the engine computer opens it by briefly connecting the other wire to ground, many times a second. Direct-injection engines work the same way in principle but use much higher drive voltages from a dedicated driver in the computer. Cylinder 1 is usually at the timing-belt or chain end of an inline engine; on V engines its bank and position vary by maker. The computer watches the voltage on the injector control wire each time it switches. When the circuit is complete, it sees a characteristic voltage spike as the injector closes. If the wire stays at the wrong voltage, or no spike appears, it decides the circuit is open and sets P0201. Because an electrical fault is clear-cut, many cars set this code and light the check engine lamp on the first trip. P0301 for a cylinder 1 misfire often appears with it. ## What are the symptoms of P0201? - Check engine light on, often with misfire code P0301 - Rough idle or shaking, as if the engine is missing a cylinder - Loss of power and hesitation when accelerating - Worse fuel economy - Hard starting on some engines ## What causes P0201? Ranked from most to least likely. Check them in this order: the cheap, common causes first. 1. **Failed cylinder 1 injector coil** (most common). The fine wire winding inside the injector can break from heat and vibration, leaving the circuit open. It shows up more on high-mileage engines, and the injector may work when cold and cut out once hot. Unplugging it and measuring resistance across its terminals shows an open circuit or a value far outside the maker's specification. 2. **Damaged injector connector or wiring** (common). Injector connectors sit in a hot spot on top of the engine, and their plastic clips grow brittle and crack, letting the plug back off. Wires can chafe, break near the plug or be chewed by rodents. A plug left loose after spark plug or intake work is a frequent cause. Wiggling the harness at idle often reproduces it. 3. **Loss of injector power feed** (less common). If the fuse, relay or supply wire feeding the injectors fails, every injector on that feed loses power. One feed may serve all injectors or one bank, so several injector codes usually appear together. Checking for 12 volts at the cylinder 1 connector with the key on confirms whether power is reaching it. 4. **Engine computer injector driver failure** (rare). The computer contains a separate switching circuit, called a driver, for each injector. A shorted injector or a wiring short can overload it and damage it. Suspect the driver when the injector, wiring and power all test good but the control wire never pulses. Replacing or repairing the computer usually requires programming it to your vehicle. ## How do you diagnose P0201? 1. Read all codes; several injector codes at once suggest a shared power feed, fuse or relay. 2. Check that the cylinder 1 injector connector is fully seated and its lock tab is intact. 3. Unplug the injector and measure its resistance, comparing it with the specification for your engine. 4. With the key on, check for supply voltage at the connector, then use a test light or injector noid light to see if the computer pulses the control wire. 5. Trace the harness from the injector toward the computer, looking for chafing, heat damage or rodent bites. ## How do you fix P0201, and what does it cost? | Fix | Typical cost | What it involves | | --- | --- | --- | | Repair injector connector or wiring | $100-$350 | A pigtail connector replacement or harness splice. | | Replace cylinder 1 fuel injector (port injection) | $200-$550 | More when the intake manifold must come off to reach it. | | Replace cylinder 1 fuel injector (direct injection) | $400-$1,100 | Includes new seals; some makers recommend extra parts or coding. | | Repair or replace engine computer | $700-$1,800 | Only after the injector and wiring test good; includes programming. | Full price breakdowns: [fuel injector replacement cost](/cost/fuel-injector-replacement). ## Is it safe to drive with P0201? > **Drive to a shop this week.** Drive only gently and only as far as a shop. A dead injector means cylinder 1 is not firing, which cuts power and can stall the engine in traffic. If the check engine light flashes or the engine shakes badly, stop and have the car towed. ## Will P0201 fail an emissions test? P0201 lights the check engine lamp and fails an OBD-based emissions test in most states. A dead cylinder also raises emissions and can damage the catalytic converter if other faults add unburned fuel. The misfire monitor rechecks quickly after a fix, but clearing codes resets the other readiness monitors, so drive several days before a retest. ## After the repair: clearing P0201 Clear the codes and start the engine; it should idle smoothly within a few seconds if the fault is fixed. Watch the cylinder 1 misfire counter on a scan tool at idle and during light acceleration, and wiggle the harness gently to confirm the connection holds. Drive for several days. No return of P0201 or P0301 means the repair worked. ## How to prevent P0201 - Reconnect and lock every injector connector after spark plug, coil or intake work. - Replace brittle injector connector clips before they crack and let the plug loosen. - Keep rodents away from parked cars with deterrents and by removing nesting material under the hood. - Never fit a higher-rated fuse if the injector fuse blows; find the short. - Use injectors with the correct resistance and connector for your exact engine. ## Codes often seen with P0201 - [P0261](/codes/p0261): Cylinder 1 Injector "A" Circuit Low - [P0301](/codes/p0301): Cylinder 1 Misfire Detected - [P0300](/codes/p0300): Random/Multiple Cylinder Misfire Detected - [P0171](/codes/p0171): System Too Lean (Bank 1) - [P0230](/codes/p0230): Fuel Pump Primary Circuit ## Frequently asked questions ### Can I drive with a P0201 code? Only short distances, and gently. With an open injector circuit, cylinder 1 usually gets no fuel, so the engine shakes, loses power and may stall. Drive straight to a shop and avoid highways. If the engine runs very badly or the check engine light flashes, have the car towed. ### What causes P0201? P0201 is usually caused by a failed injector coil, a loose or broken connector, or damaged wiring to cylinder 1. A blown fuse or lost power feed is the cause when several injector codes appear together. A failed injector driver inside the engine computer is possible but rare. ### How much does it cost to fix P0201? Most P0201 repairs cost $100 to $1,100 at an independent shop. Wiring or connector fixes run about $100 to $350. A port fuel injector costs $200 to $550 installed, and a direct-injection injector $400 to $1,100. An engine computer replacement, if needed, runs $700 to $1,800. ### What is the difference between P0201 and P0301? P0201 is an electrical code saying the cylinder 1 injector circuit is open or faulty. P0301 means the computer counted misfires on cylinder 1, which can come from many causes. When both appear, the injector circuit is the likely reason for the misfire, so fix P0201 first. ### Can I fix P0201 myself? You can do the first checks yourself: confirm the connector is fully seated, look for broken wires and measure injector resistance with a multimeter. Replacing a port injector is a moderate job on many engines. Direct-injection injectors run at high pressure and voltage, so leave those to a shop. ### Which cylinder is cylinder 1? On most inline four- and six-cylinder engines, cylinder 1 is at the end with the timing belt or chain. On V6 and V8 engines it depends on the maker, so check a repair manual or a cylinder diagram for your engine before testing or replacing parts. ### Will fuel injector cleaner fix P0201? No, injector cleaner cannot fix P0201 because the code is electrical, not a clogged injector. Cleaner removes deposits but cannot repair a broken coil, loose connector or damaged wire. Diagnose the circuit with a multimeter or test light instead of adding chemicals to the tank. ### Will P0201 damage my engine? Not directly, since a dead injector simply leaves cylinder 1 without fuel. But the engine runs unevenly, which strains engine mounts and can stall the car at a bad moment. On direct-injection engines, an injector stuck partly open can wash oil from the cylinder wall, so prompt diagnosis matters. ### Will P0201 pass an emissions test? No, with the check engine light on, a car with P0201 fails an OBD-based emissions test in most states. A dead cylinder also tends to set misfire codes. Fix the circuit, clear the codes and drive for several days so the readiness monitors complete before you go back. ### Why did P0201 appear after spark plug work? Working near the injectors can knock a connector loose or crack its brittle lock tab, especially on engines where the coils or intake must be moved to reach the plugs. Check that the cylinder 1 injector plug is fully seated and clicked in. This simple cause is surprisingly common. ## Sources - [SAE J2012: Diagnostic Trouble Code Definitions](https://www.sae.org/standards/content/j2012_201812/) - [EPA: On-Board Diagnostics (OBD)](https://www.epa.gov/state-and-local-transportation/vehicle-emissions-board-diagnostics-obd) ## Other fuel and air metering codes - [P0171 System Too Lean (Bank 1)](https://diagxcar.com/codes/p0171) - [P0172 System Too Rich (Bank 1)](https://diagxcar.com/codes/p0172) - [P0174 System Too Lean (Bank 2)](https://diagxcar.com/codes/p0174) - [P0175 System Too Rich (Bank 2)](https://diagxcar.com/codes/p0175) - [P0217 Engine Coolant Over Temperature Condition](https://diagxcar.com/codes/p0217) - [P0230 Fuel Pump Primary Circuit](https://diagxcar.com/codes/p0230) - [P0261 Cylinder 1 Injector "A" Circuit Low](https://diagxcar.com/codes/p0261) - [P0299 Turbocharger/Supercharger "A" Underboost Condition](https://diagxcar.com/codes/p0299) ## Symptoms - [Why is my car idling rough?](https://diagxcar.com/symptoms/rough-idle) - [Why does my car shake at idle?](https://diagxcar.com/symptoms/car-shakes-at-idle) - [Why does my car hesitate when I accelerate?](https://diagxcar.com/symptoms/car-hesitates-when-accelerating) - [Why does my car lose power when accelerating?](https://diagxcar.com/symptoms/car-loses-power-when-accelerating) ## Repair costs - [Fuel injector replacement cost](https://diagxcar.com/cost/fuel-injector-replacement): $300-$1,500 --- Source page: https://diagxcar.com/codes/p0201 Updated: 2026-11-03 General information, not a substitute for a qualified mechanic.