Suzuki Engine 2002 GRAND VITARA SQ625, Руководство по обслуживанию

Страница: 89 / 834

6-84 ENGINE GENERAL INFORMATION AND DIAGNOSIS (G16/J20 ENGINES)
DTC P0300 Random Misfire Detected
DTC P0301 Cylinder 1 Misfire Detected
DTC P0302 Cylinder 2 Misfire Detected
DTC P0303 Cylinder 3 Misfire Detected
DTC P0304 Cylinder 4 Misfire Detected
SYSTEM DESCRIPTION
ECM (PCM) measures the angle speed of the crankshaft based on the pulse signal from the CKP sensor and
CMP sensor for each cylinder. If it detects a large change in the angle speed of the crankshaft, it concludes
occurrence of a misfire. When the number of misfire is counted by the ECM (PCM) beyond the DTC detecting
condition, it determines the cylinder where the misfire occurred and outputs it as DTC.
DTC DETECTING CONDITION AND TROUBLE AREA
DTC CONFIRMATION PROCEDURE
1) Connect scan tool to DLC with ignition switch OFF.
2) Turn ON ignition switch and clear DTC, pending DTC and freeze frame data by using scan tool and start
engine.
3) Increase vehicle speed to speed recorded as freeze frame data (V) ±5 km/h when detecting misfire.
4) Keep driving above vehicle speed for 5 min.
5) Stop vehicle and check DTC (or pending DTC) by using scan tool.
DTC DETECTING CONDITION TROUBLE AREA
DTC
P0300
• Misfire which causes catalyst to overheat during 200
engine revolutions is detected at 2 or more cylinders.
(MIL flashes as long as this misfire occurs continu-
ously.)
• Misfire which affects exhaust emission adversely
during 1000 engine revolutions is detected at 2 or
more cylinders (2 driving cycles detection logic)
• Ignition system
• Fuel injector and its circuit
• Fuel line pressure
• Engine compression
• Abnormal air drawn in
• EGR system
• Fuel level sensor
• Valve clearance (valve lash adjuster)
• Valve timing
DTC
P0301,
P0302,
P0303,
P0304
• Misfire which causes catalyst to overheat during 200
engine revolutions is detected at 1 cylinder. (MIL
flashes as long as this misfire occurs continuously.)
• Misfire which affects exhaust emission adversely
during 1000 engine revolutions is detected at 1 cylin-
der (2 driving cycles detection logic)
WARNING:
• When performing a road test, select a place where there is no traffic or possibility of a traffic acci-
dent and be very careful during testing to avoid occurrence of an accident.
• Road test should be carried out with 2 persons, a driver and a tester, on a level road.
NOTE:
Check to make sure that the following conditions are satisfied when using this “DTC Confirmation
Procedure”.
• Intake air temp. : –8 – 70°C (18 – 158°F)
• Engine coolant temp. : –8°C, 18°F or higher
• Altitude (barometric pressure) : 2400 m, 8000 ft or less (560 mmHg, 75 kPa or more)