2001 SUZUKI GRAND VITARA Owners Manual

6-1-96 ENGINE GENERAL INFORMATION AND DIAGNOSIS (H27 ENGINE)
DTC P0430 Catalyst System Efficiency Below Threshold (Bank 2)
SYSTEM DIAGRAM
CIRCUIT DESCRIPTION
Exhaust oxygen concentration at the pre-catalyst and the post-catalyst of WU-TWC is detected from HO2S-1
and HO2S-2 respectively and accordingly ECM (PCM) controls the closed loop which then controls the fuel
injection volume. (Refer to Section 6E2.) While the above control is going on and if WU-TWC is in good condi-
tion, the output voltage of HO2S-2 is maintained at specified level. As WU-TWC becomes deteriorated, even
when the above control is going on, the exhaust gas which has passed TWC then passes HO2S-2 at the
exhaust oxygen concentration similar to that of the pre-catalyst without being oxygenated or converted. Thus,
waveforms of HO2S-1 and HO2S-2 output voltages become alike. ECM (PCM) judges deterioration of WU-TWC
by comparing waveforms of HO2S-1 and HO2S-2.
DTC DETECTING CONDITION AND TROUBLE AREA
1. HO2S-1 (Bank-2) 4. TWC
2. HO2S-2 (Bank-2) 5. ECM (PCM)
3. WU-TWC
DTC DETECTING CONDITION TROUBLE AREA
While running under conditions described for DTC CON-
FIRMATION PROCEDURE, output waveform of HO2S-1
becomes similar to that of HO2S-2.
(2 driving cycle detection logic)• Exhaust gas leakage
• Warm up three way catalytic converter
• Heated oxygen sensor – 2 or its circuit
•ECM (PCM)

ENGINE GENERAL INFORMATION AND DIAGNOSIS (H27 ENGINE) 6-1-97
DTC CONFIRMATION PROCEDURE
1) Connect scan tool to DLC with ignition switch OFF.
2) Turn ON ignition switch and clear DTC, pending DTC and freeze frame data by using scan tool.
3) Increase vehicle speed to 80 – 90 km/h (50 – 56 mph).
4) Keep above vehicle speed for 5 min. or more (Throttle valve opening is kept constant in this step).
5) Stop vehicle and check if pending DTC exists by using scan tool. If not, check if catalyst monitoring test has
completed by using scan tool. If not in both of above checks (i.e., no pending DTC and catalyst monitoring
test not completed), check vehicle condition (environmental) and repeat Step 3) through 5).
TROUBLESHOOTING
WARNING:
When performing a road test, select a place where there is no traffic or possibility of a traffic acci-
dent and be very careful during testing to avoid occurrence of an accident.
Road test should be carried out with 2 persons, a driver and a tester, on a level road.
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)
Step Action Yes No
1 Was “ENGINE DIAG. FLOW TABLE” per-
formed?Go to Step 2. Go to “ENGINE DIAG.
FLOW TABLE” in this
section.
2 Exhaust system visual inspection :
1) Check exhaust system for leaks, damage
and loose connection.
Is it in good condition?Go to Step 3. Repair or replace.
3 HO2S-2 output voltage check :
1) Check output voltage of HO2S-2 referring
Step 2 of DTC P0156 Diag. Flow Table.
Is check result satisfactory?Replace warm up three
way catalytic converter.Check “RED/YEL” and
“GRY/YEL” wires for open
and short, and connec-
tions for poor connection.
If wires and connections
are OK, replace HO2S-2.

6-1-98 ENGINE GENERAL INFORMATION AND DIAGNOSIS (H27 ENGINE)
DTC P0443 Evap Control System Purge Control Valve Circuit Malfunction
SYSTEM/WIRING DIAGRAM
DTC DETECTING CONDITION AND TROUBLE AREA
DTC CONFIRMATION PROCEDURE
1. Main fuse 3. EVAP canister purge valve
2. Main relay 4. ECM (PCM)
DTC DETECTING CONDITION TROUBLE AREA
Monitor signal of EVAP canister purge valve is different
from command signal. (Circuit open or short)
(2 driving cycle detection logic)• EVAP canister purge valve and its circuit
•ECM (PCM)
WARNING:
When performing a road test, select a place where there is no traffic or possibility of a traffic acci-
dent and be very careful during testing to avoid occurrence of an accident.
Road test should be carried out with 2 persons, a driver and a tester, on a level road.
NOTE:
Check to make sure that following condition is satisfied when using the “DTC Confirmation Proce-
dure.”
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)

ENGINE GENERAL INFORMATION AND DIAGNOSIS (H27 ENGINE) 6-1-99
1) Connect scan tool to DLC with ignition switch OFF.
2) Turn ON ignition switch and clear DTC, pending DTC and freeze frame data by using scan tool.
3) Start engine and warm up it completely.
4) Increase vehicle speed to 55 km/h (35 mph) or more.
5) Keep driving above vehicle speed for 20 min or more (Change of vehicle speed is permitted in this step).
6) Release accelerator pedal, stop vehicle and run engine at speed for 2 min.
7) Check DTC and pending DTC by using scan tool.
TROUBLESHOOTING
Step Action Yes No
1 Was “ENGINE DIAG. FLOW TABLE” per-
formed?Go to Step 2. Go to “ENGINE DIAG.
FLOW TABLE” in this
section.
2 Check EVAP canister purge system for opera-
tion referring to “EVAP CANISTER PURGE
SYSTEM INSPECTION” in this section.
Is check result satisfactory?Intermittent trouble or
faulty ECM (PCM).
Check for intermittent
referring to “INTERMIT-
TENT AND POOR CON-
NECTION” in Section 0A.Go to Step 3.
3 Check EVAP canister purge valve for resistance
referring to “EVAP CANISTER PURGE VALVE
INSPECTION” in this section.
Is resistance as specified?“GRN/BLK” or “BLU/BLK”
circuit open or short.
If wire and connections
are OK, substitute a
known-good ECM (PCM)
and recheck.Replace EVAP canister
purge valve.

6-1-100 ENGINE GENERAL INFORMATION AND DIAGNOSIS (H27 ENGINE)
Evap canister purge system inspection
1) Warm up engine to normal operating temperature.
2) Hoist vehicle so that all wheels rotate freely.
3) Set M/T in “Neutral” or A/T in “P” position and parking brake.
4) Disconnect purge hose (1) from EVAP canister.
5) Place finger against the end of disconnected hose (1) and
check that vacuum is not felt there when engine is running at
idle speed.
6) Release parking brake lever, set transfer in “2H” and M/T in
“1st” or A/T in “L”.
7) Also check that vacuum is felt when engine speed is
increased to higher than about 1,500 r/min. and keep it for 3
min. or more. If check result is not described in steps 5) and
7), check EVAP canister purge valve, wire harness and vac-
uum passage.
Vacuum passage inspection
Start engine and run it at idle speed. With finger placed against
vacuum nozzle (1), check that vacuum is applied.
If it is not applied, clean vacuum passage by blowing compressed
air.
WARNING:
Make sure that transfer is set to “2H” range position for
this check. If it is set to “4H” or “4L” position, front and
rear wheels turn at high speed and a very dangerous sit-
uation may occur.
1

ENGINE GENERAL INFORMATION AND DIAGNOSIS (H27 ENGINE) 6-1-101
Vacuum hose inspection
Check hoses for connection, leakage, clog and deterioration.
Replace as necessary.
Evap canister purge valve and its circuit inspection
1) Connect SUZUKI scan tool to DLC (1) with ignition switch
OFF and disconnect vacuum hoses from each pipe.
2) Turn ignition switch ON, clear DTC and select “MISC TEST”
mode on SUZUKI scan tool.
3) Check purge valve for operation and vacuum passage for
clog when valve is switched ON and OFF by using SUZUKI
scan tool.
If check result is not described, check vacuum hoses, purge
valve, wire harness and connections.
EVAP canister purge valve :
Valve OFF [A] : When blowing into hose “A”, air should
not come out of hose “B”.
Valve ON [B] : When blowing into hose “A”, air should
come out of hose “B”.
Evap canister purge valve inspection
1) With ignition switch OFF, disconnect coupler from canister
purge valve.
2) Check resistance between two terminals of EVAP canister
purge valve (1).
If resistance is as specified, proceed to next operation check.
If not, replace.
Resistance of EVAP canister purge valve :
28 – 35
Ω
ΩΩ Ω at 20°C (68°F)
3) Disconnect vacuum hoses from intake manifold and its EVAP
canister.
4) With coupler disconnected, blow into hose “A” (1). Air should
not come out of hose “B” (2).

6-1-102 ENGINE GENERAL INFORMATION AND DIAGNOSIS (H27 ENGINE)
5) Connect 12 V-battery to EVAP canister purge valve (3) termi-
nals. In this state, blow hose “A” (1).
Air should come out of hose “B” (2).
If check result is not as described, replace EVAP canister
purge valve.
6) Connect vacuum hoses.
7) Connect EVAP canister purge valve coupler securely.WARNING:
Do not suck the air through valve. Fuel vapor inside valve
is harmful.

ENGINE GENERAL INFORMATION AND DIAGNOSIS (H27 ENGINE) 6-1-103
DTC P0460 Fuel Level Sensor Circuit High Input
WIRING DIAGRAM/CIRCUIT DESCRIPTION
DTC DETECTING CONDITION AND TROUBLE AREA
DTC CONFIRMATION PROCEDURE
1) Connect scan tool to DLC with ignition switch OFF.
2) Turn ON ignition switch and clear DTC, pending DTC and freeze frame data by using scan tool and run
engine for 1 min.
3) Check pending DTC by using scan tool.
1. Fuel level sensor
2. Fuel meter in combination meter
3. ECM (PCM)
DTC DETECTING CONDITION TROUBLE AREA
Fuel level sensor output voltage higher than specified
value is detected for specified time.
(2 driving cycle detection logic)•Fuel level gauge or its circuit
•Fuel level sensor or its circuit
•ECM (PCM)
NOTE:
Check to make sure that following condition is satisfied when using this “DTC CONFIRMATION PRO-
CEDURE”.
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)