Suzuki 2000 Grand Vitara SQ625 Service Manual page 67

DTC CONFIRMATION PROCEDURE
WARNING:
D 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.
D 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 PRO-
CEDURE.
D Intake air temp.: –8_C, 18_F or higher
D Engine coolant temp.: –8 – 110_C (18 – 230_F)
D 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 (Change of vehicle speed is permitted
in this step).
5) Keep driving 50 – 60 km/h (30 – 40 mph) for 8 min. or more.
6) Stop vehicle and check if DTC and pending DTC exists by using scan tool. If not, check if oxygen sensor monitor-
ing test has completed by using scan tool. If not in both of above checks (i.e., no pending DTC and oxygen sen-
sor monitoring test not completed), check vehicle conditions (environmental) and repeat Steps 3) through 6).
TROUBLESHOOTING (DTC P0136)
STEP
1 Was "ENGINE DIAG. FLOW TABLE" performed?
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 voltage
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
ENGINE DIAGNOSIS (G16 / J20 ENGINES) 6-63
YES
Go to Step 2.
Go to Step 4.
"R/G" or "Gr/Y" 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 "Intermittent
and Poor Connection"
in Section 0A.
NO
Go to "ENGINE
DIAG. FLOW
TABLE".
Go to Step 3.
Replace HO2S-2.
Go to DTC P0171/
P0172 Diag. Flow
Table.