P0304

Test 1 - 2:

Test 3 - 5:

Test 6 - 8:

Test 9 - 12:

Test 13 - 16:

SYMPTOM
P0304-CYLINDER # 4 MISFIRE

TEST NOTE
This symptom is diagnosed using the 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 1% misfire rate is measured during two trips, or with a 6% to 30% misfire rate during one trip.

POSSIBLE CAUSES
- Intermittent misfire
- Visual inspection
- ASD relay output circuit
- Engine mechanical problem
- Ignition coil
- Coil control circuit
- Spark plug
- Checking fuel pressure
- Fuel pump inlet strainer plugged
- Restricted fuel supply line
- Fuel pump module
- Checking fuel leak down
- Fuel injector
- Injector control circuit
- PCM