Code
P0275
GWM
P — Powertrain
- 5 cylinder is incorrectly balanced
Views:
UK: 5
EN: 8
RU: 5
AI status
Completed
Completed
100%
Causes
- Faulty spark plug in cylinder 5
- Failed or weak ignition coil/coil pack for cylinder 5
- Fuel injector stuck open, clogged, or leaking on cylinder 5
- Low compression (worn rings, damaged piston, burned/soft valves, head gasket)
- Vacuum or intake leak affecting cylinder 5
- Low or unstable fuel pressure / weak fuel pump
Symptoms
- Check Engine Light (MIL) illuminated
- Rough idle or vibration at idle
- Visible engine misfire under load or acceleration
- Loss of power and hesitation under acceleration
- Increased fuel consumption and higher emissions
- Possible audible popping/backfire in intake or exhaust
What to check
- Read and record freeze frame and live-data from a scan tool; note misfire counts and engine load/RPM at fault
- Check for additional codes (P0300, P0171/P0174, cam/crank correlation codes)
- Compare cylinder-specific misfire counters while running (confirm cylinder 5 is the reported source)
- Inspect spark plug condition and gap on cylinder 5; measure plug resistance if applicable
- Swap ignition coil from cylinder 5 with another cylinder to see if misfire follows the coil
- Swap injector between cylinder 5 and another cylinder (or perform injector balance/test) to check if fault moves
Signal parameters
- Cylinder 5 misfire count (events/min or misfires/1k revs)
- Short-term fuel trim (STFT) %, long-term fuel trim (LTFT) % — look for large positive values indicating lean condition
- Injector pulse width for cylinder 5 (ms) compared to other cylinders
- Fuel rail pressure (refer to OEM spec) and stability (kPa/psi)
- Spark coil primary/secondary resistance (ohms) vs specification
- Crank and cam sensor signal amplitude and waveform (V) and phase correlation
Diagnostic algorithm
- Connect a capable scan tool, read DTCs and freeze-frame; confirm P0275 and check for related codes
- Verify misfire is present: observe misfire counters and run the engine to reproduce condition
- Inspect spark plug for fouling/damage; replace plug for cylinder 5 if suspect and re-test
- Swap ignition coil from cylinder 5 with another cylinder; if misfire follows coil, replace coil
- Perform a secondary ignition test (spark pattern or coil secondary test) if coil swap is inconclusive
- Swap fuel injector with another cylinder or perform an injector flow/activation test; if misfire follows injector, repair/replace injector
- Measure fuel rail pressure and inspect fuel system (filter, pump, regulator); repair if outside spec
- Perform a compression test on cylinder 5; if low, perform a leak-down test to identify valves/gasket/piston issues and repair as required
- Inspect wiring and connectors to coil and injector for continuity, shorts to ground, or open circuits; repair any faults
- Check for intake manifold or vacuum leaks near cylinder 5 (smoke test); repair leaks and re-evaluate
- Verify cam/crank correlation and timing; correct timing chain/belt or replace sensors if out of spec
- If all per-cylinder components and mechanical tests pass, consider ECM/PCM failure or intermittent harness issues and follow manufacturer diagnostic procedures
Likely causes
- Ignition coil or spark plug failure on cylinder 5
- Injector malfunction (clogged, electrically open, or leaking) on cylinder 5
- Low compression on cylinder 5 (valve, piston, or head gasket issue)
- Wiring/connector fault to coil or injector for cylinder 5
- Intake/vacuum leak localized to that cylinder
Fault status
Status
MIL on. ECM stored code P0275 — cylinder 5 misfire detected. Continued driving may increase emissions and damage the catalytic converter. Further diagnosis required to identify root cause.
Repair difficulty: Medium
Diagnostic time: 1–4 hours
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