P0306: Cylinder 6 Misfire Detected
The ECM detects crankshaft speed drop on Cylinder #6.
Driveability & Safety Advisory
Drive short distances only.
Official Manufacturer TSB Advisories
Factory Condition: Cylinder 6 ignition coil overheats due to tight packaging near firewall under microfilter cowl.
Physical Component Location & Service Access
Rearmost cylinder on Inline-6 engines (BMW), or middle/rear cylinder on V6 engines.
Electrical Specifications & Live PID Benchmarks
Scan Tool Live Data Targets
Digital Multimeter (DMM) Specs
Documented Model-Specific Case Studies
Root Cause: Cylinder 6 coil failed from exhaust heat.
Verified Fix: Replace coil.
Technician Inspection & Testing Workflow
Swap coil with Cylinder 1.
Check spark plug condition.
Check injector.
Recommended Diagnostic Tools & Verified Parts
BlueDriver Bluetooth Pro OBDII Scan Tool
Wireless sensor telemetry & enhanced diagnostics (Engine, ABS, Airbag). Delivers verified vehicle repair reports.
Autel AutoLink AL519 / AL319 OBD2 Scanner
Color screen standalone scanner. One-click I/M emissions readiness status, freeze-frame data, live DTC reset.
Ram-Pro Inline Engine Ignition Spark Tester & Gap Gauge
Quickly verify if spark plug coils are firing with high-intensity visual spark indicator. Includes electrode gap measure tool.
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Cost Breakdown
Tools & Parts Matrix
Diagnostic Questions & Answers
Why does Cylinder 6 fail most frequently on BMW inline-6 engines?
Cylinder 6 is packed tightly against the firewall under the cabin filter cowl, where heat dissipation is poorest, causing thermal degradation of the coil.