P0304

Tests 1 - 4:

Tests 5 - 7:

Tests 8 - 11:

Test 12:

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 % (1.5 % LEV) misfire rate is measured during two trips, or with a 10 % - 30 % misfire rate during one trip.

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