DTC P0300, DTC P0301, DTC P0302, DTC P0303 &/Or DTC P0304: Notes

WARNING: This page is about a different car, the 2003 Toyota RAV4. However, it is still accessible from the selected car via links, so may be relevant.

Code Definition

DTC P0300: Random/Multiple Cylinder Misfire Detected.
DTC P0301: Cylinder No. 1 Misfire Detected.
DTC P0302: Cylinder No. 2 Misfire Detected.
DTC P0303: Cylinder No. 3 Misfire Detected.
DTC P0304: Cylinder No. 4 Misfire Detected.

CAUTION: If Engine Control Module (ECM) replacement is instructed in following test, always ensure ECM electrical connectors and ground circuits are okay. If either are defective, repair and repeat testing to confirm ECM malfunction. If ECM is replaced, ECM must be programmed with proper ignition key code for engine immobilizer system. For programming procedures, see COMPUTER RELEARN PROCEDURES - TOYOTA article in GENERAL INFORMATION, or appropriate ENGINE IMMOBILIZER SYSTEMS article in ACCESSORIES & EQUIPMENT.

NOTE: For any particular 200 revolutions of engine, misfiring which could result in overheating of catalyst is detected. This will cause MIL to blink (1 trip detection logic).

NOTE: For any particular 1000 revolutions of engine, misfiring which could result in a deterioration of emissions. This will cause MIL to light up (2 trip detection logic).

NOTE: When 2 or more DTCs for misfiring cylinder are recorded repeatedly and DTC P0300 does not exist, it indicates misfires were detected and recorded at different times. If misfire cannot be reproduced, the reason may be because vehicle was driven with a lack of fuel, improper fuel, fouled spark plug or etc.

NOTE: Cylinder No. 1 is at timing chain end of engine and cylinder No. 4 is at flywheel end of engine.