EN

Severity: Moderate Code type: Generic (all makes)

P0201 Code: Injector Circuit / Open – Cylinder 1

The ECU sees an open or faulty electrical circuit to injector 1, so cylinder 1 is probably getting no fuel.

Safety first · Consult a professional

  • Fuel vapor is flammable. No smoking or open flames; work outdoors and fix fuel leaks before driving.

At a glance

Severity: 3/5 – Moderate3/5

Severity: Moderate

Meaning
Injector Circuit / Open – Cylinder 1
System
Fuel & Air Metering · Powertrain
Safe to drive?
With caution
Typical repair cost
$0–$1,500
DIY difficulty
Moderate

P0201 is an electrical code. Each time the ECU switches injector 1 it expects current to flow through the coil and, at switch-off, a sharp voltage spike as the coil's magnetic field collapses. When that signature is missing, the circuit is open or out of range and the code sets. It says nothing about spray pattern: a gummed-up injector with a healthy coil gives a misfire (P0301) or lean code, not P0201. On most transverse four-cylinders, cylinder 1 sits at the timing belt or chain end, usually the passenger side, next to the camshaft sensor, the VVT solenoid and often the coolant outlet. On longitudinal engines in rear-drive cars and trucks it is the front cylinder behind the radiator. Either way it is the injector most often disturbed during timing belt, water pump and cam seal jobs.

Can I keep driving? The engine will usually run on three cylinders, rough but drivable for a short, gentle trip to a shop. Avoid highway speeds and heavy loads, and stop if the light starts flashing or you smell raw fuel.

How to read P0201

How to read P0201P10223014
  1. P Powertrain
  2. 0 Generic (SAE)
  3. 2 Fuel & air (injector circuit)
  4. 01 Specific fault

Symptoms

  • Steady miss at idle that feels like one cylinder is dead
  • Check engine light on, with P0301 usually stored as well
  • Noticeable loss of power when climbing or merging
  • Engine shakes more with the A/C on at idle
  • Code that appeared right after timing belt, water pump or valve cover work

Possible causes

Ranked by how often each cause is behind this code (editorial estimate).

  1. Injector 1 connector unplugged, half-latched or swapped with a look-alike plug after timing belt, water pump or valve cover work 28%
  2. Open coil inside injector 1 24%
  3. Harness chafed or cracked where it passes the timing cover, engine mount or a bracket at the cylinder 1 end 18%
  4. Oil or coolant wicking into the connector from a leaking cam seal, VVT solenoid or thermostat housing nearby 12%
  5. ECU driver for injector 1 failed, or on direct injection the high-side driver it shares with injector 4 10%
  6. Poorly made splice from an aftermarket add-on in the injector 1 wire 8%

Diagnosis step by step

Diagnostic flow: P02011Find cylinder 1 on your engine2Inspect the injector 1 connector3Measure injector 1's coil4Check feed and switching at the plug5Swap injector 1 with injector 26Check the wire to the ECU

  1. Find cylinder 1 on your engine

    On most transverse four-cylinders it is the cylinder closest to the timing belt or chain cover. On longitudinal engines it is the front cylinder. Injector connectors may hide under an engine cover or the intake manifold, so trace the harness rather than guessing from the spark plug order.

    Tools: Flashlight

  2. Inspect the injector 1 connector

    Press the connector home until the latch clicks, then check that it really belongs to the injector: camshaft sensor and VVT solenoid plugs nearby often look almost identical. Pull it off and look for bent or pushed-back pins, green corrosion and oil or coolant inside.

    Tools: Flashlight, Screwdriver

  3. Measure injector 1's coil

    Measure resistance across the two injector pins and compare with injector 2. High-impedance port injectors usually read about 12 to 16 ohms at 68 °F, and neighbors should agree within about 1 ohm. OL means an open coil. If the code only sets when hot, measure again right after a drive.

    Tools: Multimeter

  4. Check feed and switching at the plug

    Key on, measure the feed pin at the harness connector: expect battery voltage on port-injected engines. Then plug in a noid light and crank. A good feed plus a steady flicker means the wiring and ECU are working and the injector is the suspect; no flicker means a break between the plug and the ECU, or a dead driver.

    Tools: Multimeter, OBD-II scanner

  5. Swap injector 1 with injector 2

    If injector 1 measures borderline or the fault is intermittent, swap it physically with injector 2 using new O-rings, clear the code and drive. P0202 appearing means the injector is faulty; P0201 staying means the circuit. Injector 2 is the better partner than 4 because on many direct-injection controllers 1 and 4 share a driver, which would blur the result.

    Tools: Screwdriver, OBD-II scanner

  6. Check the wire to the ECU

    With the battery and ECU disconnected, measure from the injector 1 control pin to its ECU pin; it should read under 1 ohm. It must show no continuity to ground or to the neighboring injector wires. Flex the harness at the timing cover end and at the engine mount while watching the meter.

    Tools: Multimeter

Where the parts are

Ignition: coils and spark plugs per cylinder – P02011234567
Ignition: coils and spark plugs per cylinder
  1. 1Ignition coil
  2. 2Spark plug
  3. 3Fuel injector
  4. 4Camshaft sensor
  5. 5Crankshaft sensor
  6. 6Engine computer (ECM)
  7. 7Intake manifold

Repair options & costs

RepairDIY?Estimated cost
Reseat or clean the injector 1 connector Yes $0–$120
Replace injector 1 connector pigtail Yes $60–$200
Repair chafed harness at the timing end No $120–$350
Replace injector 1 (port or direct injection) No $150–$800
Repair or replace the ECU injector driver No $500–$1,500

Rough US estimates for parts and labor; shop rates vary by region. Not a quote.

Notes by brand

Field data

Ford 3 Edge, F-150 SUPERCAB, Fusion
Chevrolet 2 Malibu

Source: NHTSA Complaints API (US government open data), analyzed by DTC mention.

Emissions / smog test impact

Will fail

P0201 with the check engine light on fails an OBD-II smog check, and the misfire it causes usually sets P0301 too. After the repair the misfire monitor clears quickly, but let the other monitors complete before testing.

Frequently asked questions

Does P0201 mean injector 1 is clogged?

No. P0201 is about the electrical circuit: an open coil, a bad connector, a broken wire or the ECU driver. A clogged injector still has a good coil, so it shows up as a misfire or lean code without P0201.

The code appeared right after my timing belt was replaced. Coincidence?

Probably not. Injector 1 sits at the timing end on most engines, and its plug is easy to knock loose, leave half-latched or swap with the camshaft sensor plug while the covers are off. Check that connection before anything else.

Why are P0201 and P0204 both set?

Cylinders 1 and 4 are companion cylinders on a four-cylinder with a 1-3-4-2 firing order. Many direct-injection ECUs share one high-side driver between them, and older batch-fire systems fire them together, so one supply or driver fault can take out both.

Will driving with P0201 hurt the catalytic converter?

Less than an ignition misfire, because a dead injector sends air rather than raw fuel into the exhaust. The engine still runs rough and lean on that cylinder, so drive only as far as the repair. If the injector is stuck open instead, raw fuel does reach the converter, so stop if you smell fuel.

Sources