Worn or fouled spark plug on cylinder 5; Failed ignition coil or coil-on-plug boot for cylinder 5; Faulty fuel injector for cylinder 5, including clogged nozzle or electrical failure; Vacuum leak at the intake manifold runner or gasket near cylinder 5; Low compression on cylinder 5 due to worn rings, valve seat issues, or head gasket failure; Damaged or chafed wiring to the cylinder 5 coil or injector; Mechanical valvetrain fault such as a collapsed lifter or worn cam lobe on cylinder 5

DTC codes / Nissan codes / P1205

P1205 · NissanCylinder 5 Misfire

Q: What does code P1205 mean?

Cylinder 5 Misfire. P1205 on Nissan vehicles indicates that the engine control module (ECM) has detected a misfire specifically on cylinder 5, typically by monitoring crankshaft speed fluctuations that occur when that cylinder fails to contribute power. The ECM sets this code when the misfire count exceeds a calibrated threshold, often within a specific engine speed and load window.

P1205 on Nissan vehicles indicates that the engine control module (ECM) has detected a misfire specifically on cylinder 5, typically by monitoring crankshaft speed fluctuations that occur when that cylinder fails to contribute power. The ECM sets this code when the misfire count exceeds a calibrated threshold, often within a specific engine speed and load window.

SystemPowertrain

Code typeNissan specific

SeverityMedium

Fix difficultyIntermediate

AreaFuel and air metering (injector circuits)

Symptoms you may notice

Check engine light illuminated, often flashing if the misfire is severe enough to damage the catalytic converter
Noticeable engine shake or vibration at idle, especially when cold
Rough running or hesitation during acceleration
Reduced power and poor fuel economy
Often no symptoms besides the warning light when the misfire is intermittent or mild
A sulfur or rotten egg smell from the exhaust if unburned fuel reaches the catalytic converter

Common causes, most likely first

Worn or fouled spark plug on cylinder 5
Failed ignition coil or coil-on-plug boot for cylinder 5
Faulty fuel injector for cylinder 5, including clogged nozzle or electrical failure
Vacuum leak at the intake manifold runner or gasket near cylinder 5
Low compression on cylinder 5 due to worn rings, valve seat issues, or head gasket failure
Damaged or chafed wiring to the cylinder 5 coil or injector
Mechanical valvetrain fault such as a collapsed lifter or worn cam lobe on cylinder 5

How to diagnose and fix it

Scan all stored and pending codes with a capable scan tool to confirm P1205 and check for related misfire or fuel trim codes
Perform a visual inspection of the cylinder 5 ignition coil, spark plug, and injector connector for damage or corrosion
Swap the cylinder 5 ignition coil with a known-good coil from another cylinder and see if the misfire follows the coil
Remove and inspect the cylinder 5 spark plug for wear, fouling, or incorrect gap, and replace if necessary
Run a compression test and, if low, a cylinder leak-down test on cylinder 5 to rule out mechanical faults
Test the cylinder 5 fuel injector for resistance, pulse signal, and spray pattern, and clean or replace as needed
Check for vacuum leaks around the intake manifold and inspect wiring continuity from the ECM to the coil and injector

Why cylinder 5 misfires are often misdiagnosed

A misfire code for a single cylinder does not always mean the ignition coil is at fault; fuel injector imbalance and vacuum leaks are common culprits that many technicians overlook.
Nissan engines with variable valve timing can set a single-cylinder misfire code when oil control valve debris affects cam phasing, mimicking an ignition fault.
A flashing check engine light indicates a misfire severe enough to overheat the catalytic converter, so continuing to drive can turn a cheap repair into an expensive converter replacement.
Compression and leak-down tests are often skipped in favor of parts swapping, but a mechanical fault on cylinder 5 will not be fixed by new coils or plugs.
Intermittent misfires that only appear when the engine is cold or under light load can be caused by a sticking injector or a marginal coil that tests fine when warm.

Can I keep driving with P1205?

If the check engine light is steady, you can drive cautiously to a repair shop, but avoid heavy acceleration and prolonged idling. If the light is flashing, stop driving immediately and have the vehicle towed, because a severe misfire can destroy the catalytic converter and cause further engine damage.

Tools that help

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Guidance is general and written for Nissan vehicles. Exact tests and values vary by model, so confirm the fault before replacing parts.