P0304

Tests 283 - 287:

Tests 288 - 290:

SYMPTOM
P0304 - CYLINDER # 4 MISFIRE

TEST NOTE
This symptom is diagnosed using the test P0300 - MULTIPLE CYLINDER MISFIRE.

WHEN MONITORED
Any time the engine is running, and the adaptive numerator has been successfully updated.

SET CONDITION
When more than a 2% misfire rate is measured during two trips, or with a 10% to 30% misfire rate during one trip.

POSSIBLE CAUSES
- Engine mechanical problem
- Erratic CAM/CRANK sensor signals
- Fuel system problem
- Misfire conditions no longer exist
- Other possible causes for misfire
- Secondary ignition or mechanical problem