Early Production (SBEC)

Test 1 - 3:

Test 4 - 6:

Test 7 - 9:

Test 10 - 13:

Test 14 - 17:

SYMPTOM
P0304-CYLINDER #4 MISFIRE

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

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

SET CONDITION
When more than a 2% (2.5% LEV) misfire rate is measured during two trips, or with a 10% to 30% misfire rate during one trip.

POSSIBLE CAUSES
- Intermittent misfire
- Visual inspection
- Ignition wire
- 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