| DESCRIPTION |
Random misfire detected |
| DETECTION CONDITION |
Determination conditions |
- Any one of the following conditions is met:
- The misfire rate for every 200 rotations of the crankshaft exceeds the specified value (misfire which may damage catalytic converter).
- The misfire rate for every 1, 000 rotations of the crankshaft exceeds the specified value (misfire going against emission regulations).
|
| Preconditions |
- Battery voltage: 9-18 V
- Engine speed: 500-6, 700 rpm
- Engine coolant temperature: 20 °C {68 °F} or more
- Not cranking
- Not stalling
- Fuel-cut control not implemented
- Crankshaft installation tolerance learning completed
- Engine condition is stabilized (not directly after gear change)
|
| Malfunction determination period |
- 200 rotations of crankshaft (misfire which may damage catalytic converter)
- 1, 000 rotations of crankshaft (misfire going against emission regulations)
|
| Drive cycle |
|
| Self test type |
|
| Sensor used |
- CKP sensor
- MAF sensor
- MAP sensor
|
| FAIL-SAFE FUNCTION |
- Limits intake air amount
- Implement fuel-cut control (if the catalytic converter may be damaged, perform fuel-cut on cylinder misfiring the most).
|
| VEHICLE STATUS WHEN DTCs ARE OUTPUT |
- Misfiring which may damage catalytic converter (number of drive cycles: 1):
- Check engine light flashes and pending code is recorded
- Drive cycle directly after above drive cycle (number of drive cycles: 2):
- Malfunction determined: check engine light is illuminated
- Normal is determined: Pending code cleared
- Rough idling, poor acceleration, stalling
|
| POSSIBLE CAUSE |
- Improper operation of ignition system
- Spark plug malfunction
- Ignition coil related wiring harness or connector malfunction
- Ignition coil malfunction
- Fuel injector malfunction
- Improper operation of fuel injector
- Fuel injector related wiring harness malfunction
- Erratic signal to PCM
- CKP sensor signal malfunction
- ECT sensor signal malfunction
- MAF sensor signal malfunction
- MAP sensor signal malfunction
- IAT sensor No. 1 signal malfunction
- APP sensor signal malfunction
- TP sensor signal malfunction
- VSS signal malfunction
- Related connector or terminals malfunction
- Related wiring harness malfunction
- Poor drive belt assembly or adhesion of oil
- Drive belt auto tensioner malfunction
- Air leakage from intake air system (between intake manifold and cylinder head)
- Engine malfunction
- Insufficient engine compression
- Engine coolant leakage to combustion chamber
- PCM malfunction
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