P0202
Cylinder 2 Injector A Circuit.
- Generic
- Powertrain
- Generic code
- Medium severity
How this code is built
- P
- SystemPowertrain
- 0
- Defined bySAE, the same on every car
- 2
- AreaFuel and air metering (injector circuit)
- 02
- FaultThe specific fault in that area
What it means
P0202 is the generic code for a fault in the cylinder 2 fuel injector control circuit. The engine control unit monitors the injector driver and its wiring, and it sets this code when the electrical signal or current it expects does not match what it sees, such as an open circuit, a short to earth or a short to voltage. It points to the circuit rather than proving the injector itself has failed.
Symptoms
- Engine misfire, especially on cylinder 2, with a rough or uneven idle
- Malfunction indicator lamp on, possibly flashing under a heavy misfire
- Hesitation, poor power or jerking under acceleration
- Hard starting or a long crank
- Increased fuel consumption or a fuel smell
- Engine may run in a reduced-power mode on some models
Possible causes
- Faulty cylinder 2 fuel injector with an open or shorted coil windinglikely
- Damaged, chafed or corroded wiring between the injector and the engine control unitlikely
- Poor connection at the injector plug or engine control unit connector, such as corrosion, bent or loose pinslikely
- Fault in the shared injector power supply or earth, such as a relay, fuse or poor earth point (depends on model)possible
- Failed injector driver inside the engine control unitrare
- Water ingress or heat damage in the harness near cylinder 2possible
How to diagnose
- Read all stored codes and freeze frame data, noting engine load, temperature and speed when the fault set, and check for other injector or misfire codes
- Visually inspect the cylinder 2 injector connector and nearby harness for chafing, heat damage, corrosion and loose pins
- Clear the code and see whether it returns immediately or only when hot, cold or when the harness is moved (wiggle test)
- Measure the injector coil resistance and compare it with the manufacturer's specification for that engine
- Check the injector supply voltage and earth with the ignition on, following the wiring diagram for the model
- Check the relevant fuses and relays and the engine control unit earth connections
- Test the wiring for continuity and shorts between the injector connector and the engine control unit connector
- Use a suitable scan tool or oscilloscope to check for a control signal at the injector during cranking, if the wiring and injector test fine
How to fix
- Replace the cylinder 2 injector if its resistance is out of specification or it fails an electrical test
- Repair or replace damaged wiring, using proper soldered and sealed joins or a new harness section
- Clean, repair or replace corroded or damaged connectors and terminals
- Restore a faulty power supply or earth, including any blown fuse or failed relay, after finding why it failed
- Replace or repair the engine control unit only after the wiring and injector are proven good, and follow any required coding or programming for the model
Can I keep driving?
Short trips are usually possible, but a misfiring or non-firing cylinder can overheat and damage the catalytic converter and affect fuel delivery. Get it checked soon, and stop driving if the warning lamp flashes or the engine runs very roughly.
Guide written by AI from the code's definition. Confirm with a diagnosis before replacing parts.