Suzuki SX4 Service Manual page 114

1A-64 Engine General Information and Diagnosis:
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) or more
• Altitude (barometric pressure): 2500 m, 8200 ft or less (560 mmHg, 74.4 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 100 km/h (62 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 troubleshooting 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?
3 MAF sensor and its circuit check
1) With ignition switch turned OFF, install scan tool.
2) Start engine and warm up to normal operation
temperature.
3) Check MAF value using scan tool. (Refer to "Scan Tool
Data" for normal value.)
Is each value within specified range?
4 MAF sensor output voltage check
1) Turn OFF ignition switch.
2) Remove ECM from its bracket with ECM connectors
connected.
3) Measure voltage between "C01-26" and "C01-27"
terminals of ECM connector referring to "Mass Air Flow
(MAF) and Intake Air Temperature (IAT) Sensor On-
Vehicle Inspection in Section 1C".
Is each value within specified range?
Action Yes
Go to Step 2.
Go to Step 3.
Go to Step 11.
Poor "C01-26" and/or
"C01-27" terminal
connection.
If OK, substitute a
known-good ECM and
recheck.
No
Go to "Engine and
Emission Control
System Check".
Repair or replace.
Go to Step 4.
Go to Step 5.