P0303

(P0303) CYLINDER #3 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.

POSSIBLE CAUSES
- ENGINE CONTROL RELAY OUTPUT CIRCUIT FUEL
- INJECTOR CONTROL CIRCUIT
- FUSED IGNITION SWITCH OUTPUT CIRCUIT
- COIL ON PLUG DRIVER CIRCUIT
- ENGINE MECHANICAL PROBLEM
- COIL ON PLUG
- SPARK PLUG
- FUEL STRAINER PLUGGED
- RESTRICTED FUEL SUPPLY LINE
- FUEL PUMP
- FUEL INJECTOR
- POWERTRAIN CONTROL MODULE



Diagnostic Test
1. CHECK FOR CURRENT DTC





Turn the ignition on. With the DRBIII, 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.