EN

Severity: Moderate Code type: Generic (all makes)

P0202 Code: Injector Circuit / Open – Cylinder 2

Injector 2's circuit is open or out of range; on an inline-four it's a middle cylinder under the intake.

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 2
System
Fuel & Air Metering · Powertrain
Safe to drive?
With caution
Typical repair cost
$0–$1,500
DIY difficulty
Moderate

When P0202 sets, the ECU has lost the normal electrical response from injector 2: either no current flows when its driver switches on, or the inductive kick at switch-off never shows up. Fuel flow itself isn't monitored, so this points to a connector, a wire, the coil or the driver, not to dirt inside the injector. On an inline-four, cylinder 2 is one of the two middle cylinders, next to cylinder 1. Its connector usually sits under the intake plenum, the throttle body or a bundle of hoses, which makes it the hardest injector to see and the one most often left half-connected after intake, throttle body or EGR work. That sheltered, warm spot is also where mice and rats like to nest and chew. On V engines, where cylinder 2 sits depends on each maker's numbering.

Can I keep driving? Expect a rough, three-cylinder feel. A short, easy drive to a shop is generally fine; skip the highway and full throttle, and pull over if the light flashes.

How to read P0202

How to read P0202P10223024
  1. P Powertrain
  2. 0 Generic (SAE)
  3. 2 Fuel & air (injector circuit)
  4. 02 Specific fault

Symptoms

  • Rough idle with a steady rhythmic miss
  • Check engine light on, often with P0302
  • Hesitation and weak pull under load
  • Code that came back after the engine sat for a while, with signs of rodents under the hood
  • Misfire that changes when the engine cover or intake duct is touched or moved

Possible causes

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

  1. Connector left loose or half-latched after intake manifold, throttle body, EGR or spark plug work that needed the plenum off 26%
  2. Open coil in injector 2 22%
  3. Rodent damage to the injector harness under the intake, often with nesting material or droppings nearby 16%
  4. Harness rubbed through against the fuel rail, a manifold stud or a bracket beneath the plenum 14%
  5. Oil from a leaking valve cover gasket or PCV hose collecting around the middle connectors 12%
  6. Failed ECU driver for injector 2 10%

Diagnosis step by step

Diagnostic flow: P02021Get eyes on the injector 2 connector2Wiggle-test with live data3Measure injector 2 and compare withinjector 14Check whether P0203 is set too5Test the wiring end to end6Swap injector 2 with injector 1

  1. Get eyes on the injector 2 connector

    Remove the engine cover and, if it is in the way, the air intake duct. A mirror and a strong light often show whether the plug is seated without pulling the plenum. Chewed insulation, nesting material or droppings mean you are looking at rodent damage, and the whole harness run needs checking.

    Tools: Flashlight

  2. Wiggle-test with live data

    With the engine idling, watch the cylinder 2 misfire counter or injector status in the scan tool while you gently flex the injector harness along the fuel rail and under the plenum. A sudden change as one section moves pinpoints the break or the loose pin.

    Tools: OBD-II scanner

  3. Measure injector 2 and compare with injector 1

    High-impedance port injectors typically read 12 to 16 ohms. Direct-injection gasoline injectors are usually around 1 to 3 ohms, so zero your meter leads first, because half an ohm of lead resistance matters at that level. A reading more than about 20 percent off its neighbor is suspect.

    Tools: Multimeter

  4. Check whether P0203 is set too

    If both middle cylinders report a circuit fault, look at what they share: the harness branch between them, a common splice, or on many direct-injection ECUs a shared high-side driver for cylinders 2 and 3. Two coils failing on the same day is rare.

    Tools: OBD-II scanner

  5. Test the wiring end to end

    Disconnect the battery and the ECU. Measure the injector 2 control wire from the harness connector to its ECU pin: under 1 ohm. Then check it has no continuity to ground or to the injector 3 wire, since insulation rubbed through between neighbors can short two circuits together.

    Tools: Multimeter

  6. Swap injector 2 with injector 1

    If the coil measures fine but the code keeps returning, exchange injectors 2 and 1 with fresh seals, clear codes and drive. If the fault becomes P0201, replace the injector; if P0202 stays, keep working on the circuit. Injector 1 is the right partner because it is not on the 2/3 shared driver used by many direct-injection systems.

    Tools: Screwdriver, OBD-II scanner

Where the parts are

Ignition: coils and spark plugs per cylinder – P02021234567
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
Reconnect or clean the injector 2 connector, plenum removal if needed Yes $0–$250
Repair rodent-damaged injector harness No $150–$500
Replace injector 2 connector pigtail Yes $60–$220
Replace injector 2 (port or direct injection) No $150–$800
Repair ECU injector driver or replace ECU No $500–$1,500

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

Notes by brand

Field data

Chevrolet 2 Malibu, Silverado 2500
Ford 2 F-150 SUPERCAB, Fusion

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

Emissions / smog test impact

Will fail

A lit check engine light with P0202 fails an OBD-II smog inspection. Once the circuit is repaired and the misfire is gone, give the car a few days of mixed driving so all readiness monitors complete.

Frequently asked questions

Why is injector 2 so hard to get to?

On most inline-fours the middle injectors sit under the intake plenum or throttle body, while injectors 1 and 4 at the ends are easier to reach. Some engines need the plenum removed just to unplug them, which is also why their connectors get forgotten after intake work.

Could mice or rats have caused P0202?

Yes, especially on cars that sit outside or unused for a while. Rodents nest in the warm space under the intake and chew wiring there. If you find damage, check the whole harness and consider a rodent-resistant wrap.

What is the difference between P0202 and P0302?

P0302 only says cylinder 2 is misfiring, for any reason from a spark plug to low compression. P0202 says the injector 2 electrical circuit is faulty. With both codes stored, fix the circuit first; the misfire usually disappears with it.

P0202 and P0203 are both set. What does that mean?

The two middle cylinders share a harness branch on most inline-fours, and many direct-injection ECUs feed them from one high-side driver. A fault in that shared part is far more likely than two separate injector failures.

Sources