Suzuki Grand Vitara Service Manual page 80

1A-73 Engine General Information and Diagnosis:
DTC Detecting Condition and Trouble Area
DTC detecting condition
• MAF volume is greater than 25 g/sec even if engine
revolution is less than 900 rpm and intake manifold
pressure is less than 45 kPa (6.35 psi) with TP less than
3.0°.
• MAF volume is lower than 4 g/sec even if engine revolution
is more than 2500 rpm and intake manifold pressure is
more than 50 kPa (7.25 psi) with TP more than 15°.
(2 driving cycle detection logic)
DTC Confirmation Procedure
WARNING
!
• When performing a road test, select a place where there is no traffic or possibility of a traffic
accident and be very careful during testing to avoid occurrence of an accident.
• Road test should be carried out by 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 temperature at engine start: –10 °C (14°F) to 80 °C (176 °F)
• Intake air temperature: –10 °C (14 °F) to 70 °C (158 °F)
• Engine coolant temperature: 70 °C (158 °F) to 150 °C (302 °F)
• Altitude (barometric pressure): 2400 m, 8000 ft or less (560 mmHg, 75 kPa or more)
1) With ignition switch turned OFF, connect scan tool.
2) Turn ON ignition switch and clear DTC using scan tool.
3) Start engine and warm up to normal operating temperature. (ECT approx. 90 – 95 °C, 194 – 203 °F)
4) Drive vehicle with engine speed: more than 2500 rpm for 1 min.
5) Increase vehicle speed to 80 km/h (45 mile/h) at 5th gear or D range.
6) Release accelerator pedal to decrease vehicle speed to 40 km/h (25 mile/h).
7) Stop vehicle and run it idle for 1 min.
8) Check DTC and pending DTC.
DTC Troubleshooting
NOTE
Before this trouble shooting is performed, read the precautions for DTC troubleshooting referring to
"Precautions For DTC Troubleshooting: ".
Step
1 Was "Engine and Emission Control System Check"
performed?
2 Visual inspection
Check MAF sensor and air intake system for:
• Objects which block measuring duct and resistor of MAF
sensor.
• Other air flow which does not pass the MAF sensor.
Are they in good condition?
www.CarGarage.ir
Action
www.CarGarage.ir
Trouble area
• Air intake system (clog or leakage)
• MAF sensor circuit
• MAF sensor
• TP sensor and/or its circuit
• MAP sensor and/or its circuit
• ECM
Yes
Go to Step 2.
Go to Step 3.
No
Go to "Engine and
Emission Control
System Check: ".
Repair or replace.