Suzuki 2000 Grand Vitara SQ625 Service Manual page 185

6-1-74 ENGINE (H25 ENGINE)
WARNING:
D When performing a road test, select a place where there is no traffic or possibility of a traffic accident
and very careful during to avoid occurrence of an accident.
D Road test, should be carried out with 2 person, a driver and tester, on a level road.
D Intake air temperature: between –14_C and 70_C (6.8_F and 158_F)
D Atmospheric pressure: higher than 560 mmHg (Altitude: lower than 2790 m (9150 ft))
D Following DTC is not detected: P0135
(1) With ignition switch OFF, connect scan tool.
(2) Turn ON ignition switch and clear DTC by using scan tool if any.
(3) Start engine and warm up to normal operating temperature.
(4) Increase vehicle speed till engine speed is reached 2000 – 3000 r/min.
(5) Keep above vehicle speed for 1 min. (Throttle valve operating is kept constant in this step.)
(6) Stop vehicle and check DTC and pending DTC by using scan tool.
DTC TROUBLESHOOTING
STEP
1 Was "ENGINE DIAG. FLOW TABLE" performed?
2 HO2S Voltage check:
(1) With ignition switch OFF, install scan tool.
(2) Operate engine for 60 sec. or more with following
condition.
Engine coolant temp > 70_C Engine coolant tem . > 70 C
Engine speed > 2000 r/min.
(3) While repeating racing engine, check "O2S B1 S1"
(HO2S voltage) displayed on scan tool.
Is less than 0.4 V voltage displayed?
3 HO2S Voltage check:
(1) Remove ECM (PCM) cover.
(2) Start engine and check voltage between C51-3-15
and C51-3-21 while repeating racing engine.
Is the voltage while fuel is cut less than 0.1 V?
4 HO2S Wire Harness check:
(1) Check "R/Bl" and "Gr/Y" wire.
Are they in good condition?
5 Fuel Injector Circuit check:
(1) Check fuel injector circuit referring to "TABLE B-2"
in this section.
Is it in good condition?
6 Fuel Injector inspection:
(1) Inspect fuel injectors (No.2, 4, 6) referring to
"ENGINE AND EMISSION CONTROL" section.
Are they in good condition?
7 Fuel Pressure inspection:
(1) Check fuel pressure referring to following
"TABLE B-3" in this section.
Is fuel pressure within specification?
ACTION YES
Go to Step 2.
Intermittent trouble.
If OK, substitute a
known-good ECM
(PCM) and recheck.
Substitute a known-
good ECM (PCM)
and recheck.
Go to Step 5.
Go to Step 6.
Go to Step 7.
Replace HO2S and
recheck.
If DTC P0151
detected, substitute a
known good ECM
(PCM) and recheck.
NO
Go to "ENGINE
DIAG. FLOW
TABLE".
Go to Step 3.
Go to Step 4.
Repair or replace.
Repair or replace.
Faulty fuel injector(s).
Repair or replace.