Suzuki GRAND VITARA XL-7 Owner's Manual page 225

6-1-64 ENGINE GENERAL INFORMATION AND DIAGNOSIS (H27 ENGINE)
NOTE:
Check to make sure that following conditions are satisfied when using this "DTC CONFIRMATION
PROCEDURE".
• Intake air temp. : – 8°C (18°F) or higher
• Engine coolant temp. : – 8 – 110°C (18 – 230°F)
• Altitude (barometric pressure) : 2400 m, 8000 ft or less (560 mmHg (75 kPa) or more)
1) Connect scan tool with ignition switch OFF.
2) Turn ON ignition switch and clear DTC, pending DTC and freeze frame data in ECM memory by using scan
tool and start engine.
3) Increase vehicle speed to 55 km/h (40 mph) or more.
4) Keep driving above vehicle speed till engine is warmed up completely (Changed of vehicle speed is permit-
ted in this step).
5) Keep driving 50 – 60 km/h (30 – 40 mph) for 8 min. or more.
6) Stop vehicle and check if pending DTC exists by using scan tool. If not, check if oxygen sensor heater moni-
toring test has completed by using scan tool. If not in both of above checks (i.e., no pending DTC and oxy-
gen sensor heater monitoring test not completed), check vehicle conditions (environmental) and repeat
Steps 3) through 6).
TROUBLESHOOTING
Step
1 Was "ENGINE DIAG. FLOW TABLE" per-
formed?
2 HO2S-2 output voltage check :
1) Connect scan tool to DLC with ignition
switch OFF.
2) Drive vehicle about 35 mph, 55 km/h for 2
min. or more.
3) Stop vehicle and check HO2S-2 output volt-
age displayed on scan tool while repeating
racing engine.
Is over and below 0.3 V indicated?
3 HO2S-2 check :
1) With ignition switch OFF, disconnect HO2S-
2 coupler.
2) Connect voltmeter between "2" and "1" of
HO2S-2 coupler.
3) Start engine and check voltmeter while
repeating racing engine.
Is over and below 0.3 V indicated?
4 Short term fuel trim check :
1) Run engine at 2000 r/min. for 60 sec.
2) With engine idling, check short term fuel
trim displayed on scan tool.
Is it within – 20 to +20 %?
Action Yes
Go to Step 2.
Go to Step 4.
"RED/BLK" or "GRY/YEL"
circuit open/short.
If wire and connection are
OK, substitute a known-
good ECM (PCM) and
recheck.
Intermittent trouble or
faulty ECM (PCM).
Check for intermittent
referring to "INTERMIT-
TENT AND POOR CON-
NECTION" in Section 0A.
No
Go to "ENGINE DIAG.
FLOW TABLE" in this
section.
Go to Step 3.
Replace HO2S-2.
Go to DTC P0171/P0172
Diag. Flow Table.