P0301

ON BOARD DIAGNOSIS LOGIC
If misfire occurs, the engine speed will fluctuate. If the fluctuation is detected by the crankshaft position sensor (POS), the misfire is diagnosed.
The misfire detection logic consists of the following two conditions.

1. One Trip Detection Logic (Three Way Catalyst Damage)
When a misfire is detected which will overheat and damage the three way catalyst, the malfunction indicator lamp (MIL) will start blinking; even during the first trip. In this condition, ECM monitors the misfire every 200 engine revolutions.
If the misfire frequency decreases to a level that will not damage the three way catalyst, the MIL will change from blinking to lighting up.
(After the first trip detection, the MIL will light up from engine starting. If a misfire is detected that will cause three way catalyst damage, the MIL will start blinking.)




2. Two Trip Detection Logic (Exhaust quality deterioration)
When a misfire that will not damage the three way catalyst (but will affect exhaust emission) occurs, the malfunction indicator lamp will light up based on the second consecutive trip detection logic. In this condition, ECM monitors the misfire for each 1,000 revolutions of the engine.

DIAGNOSTIC TROUBLE CODE CONFIRMATION PROCEDURE (Overall)

CAUTION: Always drive vehicle at a safe speed.

NOTE: If "DIAGNOSTIC TROUBLE CODE CONFIRMATION PROCEDURE" has been previously conducted, always turn ignition switch "OFF" and wait at least 10 seconds before conducting the next test.




With Consult
1. Turn ignition switch "ON", and select "DATA MONITOR" mode with CONSULT
2. Start engine and warm it up to normal operating temperature.
3. Turn ignition switch "OFF" and wait at least 10 seconds.
4. Start engine again and drive at 1,500 to 3,000 rpm at least 3 minutes.
Hold the accelerator pedal as steady as possible during driving.

NOTE: Refer to the freeze frame data for the test driving condition.

5. If 1st trip DTC is detected, go to "DIAGNOSTIC PROCEDURE.

OR

With Generic Scan Tools
1. Start engine and warm it up to normal operating temperature.
2. Turn ignition switch "OFF" and wait at least 10 seconds.
3. Start engine again and drive at 1,500 to 3,000 rpm for at least 3 minutes.
Hold the accelerator pedal as steady as possible during driving.

NOTE: Refer to the freeze frame data for the test driving condition.

4. Select "MODE 7" with GST.
5. If 1st trip DTC is detected, go to "DIAGNOSTIC PROCEDURE".

OR

Without Scan Tools
1. Start engine and warm it up to normal operating temperature.
2. Turn ignition switch "OFF" and wait at least 10 seconds.
3. Start engine again and drive at 1,500 to 3,000 rpm at least 3 minutes.
Hold the accelerator pedal as steady as possible during driving.
4. Turn ignition switch "OFF", wait at least 10 seconds, and then turn "ON".
5. Perform "Diagnostic Test Mode II (Self-diagnostic results)" with ECM.
6. If 1st trip DTC is detected, go to "DIAGNOSTIC PROCEDURE".

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DIAGNOSTIC PROCEDURE