Troubleshooting by Diagnostic Trouble Code - DTC P0301/P0302/P0303/P0304

DESCRIPTION AND OPERATION

Refer to the corresponding paragraph for DTC P0300.

DTC SET CONDITIONS

The engine control module will store one of DTCs P0301 - P0304 and illuminate the malfunction indicator lamp if, during two driving cycles, 2 misfires per 100 crankshaft revolutions are detected for the corresponding engine cylinder. Misfire frequency is measured every 200 crankshaft revolutions when the following conditions are met:

• Change in crankshaft speed per second is less than 1000 rpm.

• Crankshaft speed is within 600 - 4000 rpm.

• Engine load (injector pulse width) is greater than 2 msec.

• No fuel cut-off is active.

• Crankshaft is not being cranked by the starter.

• Vehicle is driving on a level road (acceleration value less than 0.3 g according to the acceleration sensor).

If the misfire rate increases to 5 - 25% per 200 crankshaft revolutions, there is a risk of catalytic converter damage and the malfunction indicator lamp (MIL) will flash intermittently. The catalytic converter temperature may exceed 1950°C if the misfire rate increases further. This DTC indicates that the ECM has detected an ignition system malfunction for this cylinder.

WIRING DIAGRAM

INSPECTION PROCEDURE

INSPECTION PROCEDURE