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P0304






P0304 - CYLINDER #4 MISFIRE









When Monitored and Set Condition

- When Monitored: Any time the engine is running, and the Target Learning Coefficient has been successfully updated.
- Set Condition: When more than a 1.0% misfire rate is measured during two trips.







Diagnostic Test

1. CHECK FOR CURRENT DTC





Turn the ignition on.

With the DRB III(R), read PCM DTCs.

Is this DTC present?

Yes

- For complete diagnosis of this DTC, refer to (P0301) CYLINDER #1 MISFIRE. P0301

No

- Go To 2

2. INTERMITTENT WIRING AND CONNECTORS

The conditions necessary to set this DTC are not present at this time.

NOTE: Check connectors - Clean/repair as necessary. Poor pin to terminal connections can set DTCs.
Using the wiring diagram/schematic as a guide, inspect the wiring and connectors specific to this DTC. Wiggle the wires while checking for shorts and open circuits.

NOTE: Check for any Technical Service Bulletins that may apply.

Were there any problems found?

Yes

- Repair as necessary.
- Perform POWERTRAIN VERIFICATION TEST - VER 2. Powertrain Verification Test - Ver 2

No

- The condition that caused this DTC to set is currently not present. Inspect the related wiring harness for a possible intermittent condition.