2001 SUZUKI GRAND VITARA engine

ENGINE GENERAL INFORMATION AND DIAGNOSIS (H27 ENGINE) 6-1-45
Table A-3 Malfunction Indicator Lamp Check – MIL Flashes at Ignition Switch
ON (Vehicle with Monitor Connector)
WIRING DIAGRAM/CIRCUIT DESCRIPTION
Refer to TABLE A-1.
TROUBLESHOOTING
Table A-4 Malfunction Indicator Lamp Check – MIL Does Not Flash or Just
Remains ON Even with Grounding Diagnosis Switch Terminal (Vehicle with
Monitor Connector)
WIRING DIAGRAM/CIRCUIT DESCRIPTION
Refer to TABLE A-1.
TROUBLESHOOTING
Step Action Yes No
1 MIL Flashing Pattern check:
1) Turn ignition switch ON.
Does lamp flashing pattern indicate diagnostic
trouble code?Go to Step 2. Go to “Diagnosis” in Sec-
tion 8G.
2 Diag. Switch Circuit check:
Is diag. switch terminal connected to ground via
service wire?System is in good condi-
tion.“YEL” circuit shorted to
ground. If circuit is OK
substitute a known-good
ECM (PCM) and recheck.
Step Action Yes No
1 MIL Circuit check:
1) Turn ignition switch OFF and disconnect
connectors from ECM (PCM).
Does MIL turn ON at ignition switch ON?“PPL/YEL” circuit shorted
to ground.Go to Step 2.
2 ECM (PCM) Connection check:
1) Turn ignition switch OFF.
Is connector (E61-29 connection) connected to
ECM (PCM) properly?Go to Step 3. Poor connector connec-
tion.
3 Diag. switch Terminal Circuit check:
1) Connect connectors to ECM (PCM).
2) Using service wire, ground E61-29 terminal
with connectors connected to ECM (PCM).
3) Turn ignition switch ON.
Does MIL flash?“YEL” or “BLK” circuit
open.Substitute a known-good
ECM (PCM) and recheck.

6-1-46 ENGINE GENERAL INFORMATION AND DIAGNOSIS (H27 ENGINE)
Table A-5 ECM (PCM) Power and Ground Circuit Check – MIL Doesn’t Light at
Ignition Switch ON and Engine Doesn’t Start Though It Is Cranked Up
WIRING DIAGRAM
CIRCUIT DESCRIPTION
When the ignition switch is turned ON, the main relay turns ON (the contact point closes) and the main power is
supplied to ECM (PCM).
1. MIL
2. To ignition switch
3. Main fuse
4. Main relay
5. ECM (PCM)

ENGINE GENERAL INFORMATION AND DIAGNOSIS (H27 ENGINE) 6-1-47
INSPECTION
Step Action Yes No
1 Main relay operating sound check :
Is operating sound of main relay heard at igni-
tion switch ON?Go to Step 5. Go to Step 2.
2 Fuse check :
Is main “FI” fuse in good condition?Go to Step 3. Check for short in circuits
connected to this fuse.
3 Main relay check :
1) Turn OFF ignition switch and remove main
relay.
2) Check for proper connection to main relay
at terminal 3 and 4.
3) If OK, check main relay for resistance and
operation referring to “MAIN RELAY
INSPECTION” in Section 6E2.
Is check result satisfactory?Go to Step 4. Replace main relay.
4 ECM (PCM) power circuit check :
1) Turn OFF ignition switch, disconnect con-
nectors from ECM (PCM) and install main
relay.
2) Check for proper connection to ECM (PCM)
at terminals C51-3-20, E61-9, C51-3-15 and
C51-3-4.
3) If OK, then measure voltage between termi-
nal C51-3-20 and ground, E61-9 and
ground with ignition switch ON.
Is each voltage 10 – 14 V?Go to Step 5. “BLK/WHT”, “BLU” or
“BLK/RED” circuit open.
5 ECM power circuit check :
1) Using service wire, ground terminal E61-9
and measure voltage between terminal
C51-3-15 and ground at ignition switch ON.
Is it 10 – 14 V?Check ground circuits
“BLK/GRN” and “BLK/
ORN” for open.
If OK, then substitute a
known-good ECM (PCM)
and recheck.Go to Step 6.
6 Is operating sound of main relay heard in Step
1?Go to Step 7. “BLK/RED” or “BLU/BLK”
wire open.
7 Main relay check :
1) Check main relay according to procedure in
Step 3.
Is main relay in good condition?“BLK/RED” or “BLU/BLK”
wire open.Replace main relay.

6-1-48 ENGINE GENERAL INFORMATION AND DIAGNOSIS (H27 ENGINE)
DTC P0100 (DTC No.33, 34) Mass Air Flow Circuit Malfunction
WIRING DIAGRAM
DTC DETECTING CONDITION AND TROUBLE AREA
1. Main fuse
2. Main relay
3. ECM/PCM
4. Mass air flow sensor
DTC DETECTING CONDITION TROUBLE AREA
Any one of the following conditions are detected for 5
sec. continuously.
• Engine running and more than 3 sec. after ignition
switch ON and less than 0.64 mA MAF sensor out-
put current continues for 100 msec.
• Engine running and more than 3 sec. after ignition
switch ON and more than 4.90 mA MAF sensor out-
put current continues for 100 msec.• MAF sensor circuit
• MAF sensor
• ECM (PCM)

ENGINE GENERAL INFORMATION AND DIAGNOSIS (H27 ENGINE) 6-1-49
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 at idle speed for 20 sec. or more.
3) Check DTC by using scan tool.
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 person, 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 MAF sensor check :
1) Connect scan tool to DLC with ignition
switch OFF.
2) Start engine and check MAF value dis-
played on scan tool. (Refer to “SCAN TOOL
DATA” in this section for normal value.)
Is normal value indicated?Intermittent trouble.
Check for intermittent
referring to “INTERMIT-
TENT AND POOR CON-
NECTION” in Section 0A.Go to Step 3.
3 MAF sensor power supply check :
1) With ignition switch OFF, disconnect MAF
sensor coupler.
2) With ignition switch ON, check voltage
between E154-3 of MAF sensor coupler and
ground.
Is voltage 10 – 14 V?Go to Step 4. Faulty “BLU/BLK” wire.
4 MAF sensor output voltage check :
1) With ignition switch OFF, connect MAF sen-
sor coupler.
2) Remove ECM (PCM) cover.
3) With ignition switch ON leaving engine OFF,
check voltage between C51-3-10 and C51-
3-5 terminal.
Is voltage 1.0 – 1.6 V?Poor C51-3-10 or/C51-3-5
terminal connection.
If OK, substitute a known-
good ECM (PCM) and
recheck.Faulty “PPL/WHT” wire.
Poor E154 coupler termi-
nal connection.
If wire and connection are
OK, substitute a known-
good MAF sensor and
recheck.

6-1-50 ENGINE GENERAL INFORMATION AND DIAGNOSIS (H27 ENGINE)
DTC P0110 (DTC No.23, 25) Intake Air Temp. (IAT) Circuit Malfunction
WIRING DIAGRAM
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 at idle speed and engine coolant temp. 110°C (230°F) or lower for 10 sec. or more.
3) Check DTC by using scan tool.
1. IAT sensor
2. ECM (PCM)
DTC DETECTING CONDITION TROUBLE AREA
Any one of the conditions are detected for 5 sec. con-
tinuously.
• Low intake air temperature (high voltage-high resis-
tance)
• High intake air temperature (Low voltage-low resis-
tance)• IAT sensor circuit
• IAT sensor
• ECM (PCM) malfunction

ENGINE GENERAL INFORMATION AND DIAGNOSIS (H27 ENGINE) 6-1-51
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 IAT sensor and its circuit :
1) Connect scan tool with ignition switch OFF.
2) Turn ignition switch ON.
3) Check intake air temp. displayed on scan
tool.
Is – 40°C (– 40°F) or 165°C (329°F) indicated?Go to Step 3. Intermittent trouble.
Check for intermittent
referring to “INTERMIT-
TENT AND POOR CON-
NECTION” in Section 0A.
3 Check wire harness :
1) Disconnect IAT sensor connector with igni-
tion switch OFF.
2) Check for proper connection to IAT sensor
at “LT BLU” and “GRY/YEL” wire terminals.
If OK, then with ignition switch ON, is voltage
applied to “LT BLU” wire terminal about 4 – 6 V?Go to Step 4. “LT BLU” wire open or
short, or poor C51-3-1
connection.
If wire and connection are
OK, substitute a known-
good ECM (PCM) and
recheck.
4 Check wire harness :
1) Using service wire, connect IAT sensor con-
nector terminals.
2) Turn ignition switch ON and check intake air
temp. displayed on scan tool.
Is 165°C (329°F) indicated?Replace IAT sensor. “GRY/YEL” wire open or
poor C51-3-25 connec-
tion.
If wire and connection are
OK, substitute a known-
good ECM (PCM) and
recheck.

6-1-52 ENGINE GENERAL INFORMATION AND DIAGNOSIS (H27 ENGINE)
DTC P0115 (DTC No.14, 15) Engine Coolant Temp. Circuit Malfunction
WIRING DIAGRAM
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 at idle speed for 10 sec. or more.
3) Check DTC by using scan tool.
1. ECT sensor
2. To combination (ECT) meter
3. ECM (PCM)
DTC DETECTING CONDITION TROUBLE AREA
Any one of the conditions are detected for 5 sec. continu-
ously.
• Low engine coolant temperature (high voltage-high
resistance)
• High engine coolant temperature (low voltage-low
resistance)ECT sensor circuit
ECT sensor
ECM (PCM)
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)