P0311
Cylinder 11 Misfire Detected
The appearance of the standard OBD2 trouble fault code P0311 is an indicator that your vehicle ECU triggered a threshold alert for "Cylinder 11 Misfire Detected". Understanding the root component breakdown helps avoid expensive diagnostic fees.
Driver's Summary
Your vehicle's computer logged P0311 after detecting a malfunction in the cylinder 11 misfire detected system. You may notice v12 engine running rough, raw fuel smell, flashing mil, all of which are direct consequences of this malfunction. This is not a code to ignore — the underlying fault can rapidly worsen and lead to costly repairs if driving continues.
Symptoms
V12 engine running rough, raw fuel smell, flashing MIL
Common Causes
- Defective spark plug
- Failed ignition coil
- Burnt exhaust valve
- Wiring harness issue
How to Fix
- 1 Replace spark plug
- 2 Replace ignition coil
- 3 Perform leak-down test
- 4 Repair ignition wiring
Technical Explanation
To set P0311, the PCM samples the affected circuit multiple times per second, comparing live readings against manufacturer-programmed operating windows. Misfire rate is counted per cylinder over rolling windows and compared against two thresholds: a catalyst-damaging rate (triggers flashing MIL) and an emissions-exceeding rate (triggers solid MIL). The PCM logs which cylinder is misfiring based on crankshaft position at the time of each detected event. After two failed drive cycles, the code transitions from a pending to a confirmed DTC, and the PCM activates the MIL. Clearing the code without repairing the fault will result in re-illumination within one to two complete drive cycles.
Is It Safe to Drive?
With P0311 active, your engine or transmission is not operating within design parameters. Short-term driving may seem fine, but internal damage is accumulating — particularly to defective spark plug.
Mechanic's Pro Tip
For P0311, test the solenoid's coil resistance with a multimeter before ordering parts — most solenoids should read between 14 and 40 ohms; an open (infinite resistance) or short (near zero) confirms it's failed electrically. Also verify the PCM is commanding the solenoid by backprobing the connector with a test light during the relevant operating condition — if there's no command signal, the fault is in the PCM or wiring, not the solenoid itself.
Ignition parts: 150 - 400; Valve job: 1,500+