Injector Circuit/Open Cylinder 2
The P0202 code indicates that the Powertrain Control Module (PCM) has detected a malfunction, specifically an open circuit or abnormal voltage, in the fuel injector circuit for cylinder number 2. The PCM sets this code when it monitors the injector circuit and finds that the electrical signal does not match the expected parameters during operation.
A malfunctioning fuel injector will cause a severe misfire, leading to poor performance and potential catalytic converter damage. It should be diagnosed and repaired immediately to prevent further engine or emission system damage.
Common symptoms
- Illuminated or flashing Check Engine Light
- Engine misfire and rough idle
- Noticeable lack of engine power during acceleration
- Decreased fuel economy
- Engine stalling or hesitation
Likely causes
- Faulty fuel injector on cylinder 2
- Damaged, broken, or shorted wiring in the cylinder 2 injector circuit
- Loose or corroded electrical connector at the cylinder 2 injector
- Open or shorted fuel injector harness
- Faulty Powertrain Control Module (PCM) (rare)
What to check before replacing parts
Visually inspect the wiring and connector at the cylinder 2 fuel injector
Look for: Look for frayed wires, melted insulation, or a loose, broken, or corroded connector that could cause an open circuit.
Listen to the cylinder 2 fuel injector with a mechanic's stethoscope
Look for: Listen for a steady, rhythmic clicking sound while the engine is running. A lack of clicking indicates the injector is not firing.
Test the internal resistance of the cylinder 2 fuel injector
Look for: Disconnect the injector and use a multimeter to measure its resistance. An infinite reading (open) or a reading outside the manufacturer's specified range (typically 10-18 ohms) indicates a failed injector.
Check for voltage and pulse at the injector harness
Look for: Use a noid light or multimeter on the disconnected harness to verify that the PCM is sending the proper 12-volt supply and ground pulse while the engine is cranking or running.
Test the wiring harness for continuity back to the PCM
Look for: Use a multimeter to test the wires between the injector connector and the PCM. High resistance, no continuity, or a short to ground indicates a wiring harness failure.
This page explains the generic P0202 definition and is general reference information, not a diagnosis for your specific vehicle. Actual causes, severity, and repairs vary by make, model, engine, and mileage — always confirm with a scan tool and a qualified technician before replacing parts.
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