If the ECM detects that engine speed variation indicates a misfire sufficient to cause three-way catalyst converter damage or emissions level to exceed standard value, the ECM sets DTC P0301. If the misfire rate is high enough to damage the catalyst, the MIL will flash to alert the vehicle operator.
Item | Detecting Condition | Possible Cause |
DTC Strategy |
•
Signal monitoring | 1. Poor connector connection 2. Incorrect valve timing 3. Uneven compression 4. Air leakage 5. Improper fuel pressure or dirty fuel 6. Blocked/leaking injector #1 7. Faulty injector #1 |
Enable Condition |
•
25 sec. after engine "ON"
•
No CKPS error
•
No rough road condition
•
No fuel cut-off condition | |
Threshold Value |
•
The total misfire rate is greater than 10% under driving condition (Emission threshold)
•
The total misfire rate is greater than 25% under driving condition (Catalyst damage threshold) | |
Diagnosis Time |
•
Continuous | |
MIL ON Condition |
•
3 driving cycles or immediatley (Blink) |
