2001 SUZUKI GRAND VITARA engine

ENGINE GENERAL INFORMATION AND DIAGNOSIS (H27 ENGINE) 6-1-117
Fig. for Step 2
Table B-2 Fuel Injectors and Circuit Inspection
WIRING DIAGRAM
3 Fuel pump relay check :
1) Check fuel pump relay referring to “FUEL
PUMP RELAY INSPECTION” in Section
6E2.
Is it in good condition?“BLK/WHT” or “WHT/
GRN” circuit open or poor
E61-23 connection.
If wire and connection are
OK, substitute a known-
good ECM (PCM) and
recheck.Replace fuel pump relay. Step Action Yes No
1. Fuel pump relay connector
1. To ignition switch 4. Injector No.1 7. Injector No.4 10. ECM (PCM)
2. Main fuse 5. Injector No.2 8. Injector No.5
3. Main relay 6. Injector No.3 9. Injector No.6

6-1-118 ENGINE GENERAL INFORMATION AND DIAGNOSIS (H27 ENGINE)
INSPECTION
Step Action Yes No
1 Check injector for operating sound :
Using sound scope, check each injector for
operating sound at engine cranking.
Do all 6 injectors make operating sound?Go to Step 2. Go to Step 3.
2 Wire harness check :
1) Remove ECM (PCM) cover and disconnect
connectors from ECM (PCM).
2) Check for resistance between following ter-
minals of ECM (PCM) connector discon-
nected.
Fuel injector and its circuit resistance (C51-
2-1 – C51-3-4, C51-2-2 – C51-3-4, C51-2-8 –
C51-3-4, C51-2-9 – C51-3-4, C51-2-21 – C51-
3-4 and C51-2-22 – C51-3-4) :
14.2 – 14.8
Ω
ΩΩ Ω at 20°C (68°F)
Is check result as specified?Fuel injector circuit is in
good condition.“PNK”, “PNK/BLK”, “PNK/
GRN”, “PNK/BLU”, “GRY/
GRN” and “GRY/BLK”
shorted each other.
3 Does none of 6 injectors make operating sound
at Step 1?Go to Step 4. Check coupler connec-
tion and wire harness of
injector not making oper-
ating sound and injector
itself (Refer to “FUEL
INJECTOR INSPEC-
TION” in Section 6E2).
4 Check power circuit of injectors for open and
short.
Is it normal?Check all 6 injectors for
resistance respectively.
It resistance is OK, substi-
tute a known-good ECM
(PCM) and recheck.Power circuit open or
short.

ENGINE GENERAL INFORMATION AND DIAGNOSIS (H27 ENGINE) 6-1-119
Table B-3 Fuel Pressure Inspection
SYSTEM DIAGRAM
Special tool
(A) : 09912-58441
(B) : 09912-58431
(C) : 09919-58421
INSPECTION
1. Injector 4. Fuel filter
2. Delivery pipe 5. Fuel pump
3. Fuel pressure regulator
NOTE:
Before using the following flow table, check to make sure that battery voltage is higher than 11 V. If
battery voltage is low, pressure becomes lower than specification even if fuel pump and line are in
good condition.
Step Action Yes No
1 1) Install fuel pressure gauge, referring to
“FUEL PRESSURE INSPECTION” in Sec-
tion 6E2.
2) Operate fuel pump.
Is fuel pressure then 270 – 310 kPa
(2.7 – 3.1 kg/cm
2, 38.4 – 44.0 psi)?Go to Step 2. Go to Step 5.
2
Is 200 kPa (2.0 kg/cm
2, 28.4 psi) or higher fuel
pressure retained for 1 minute after fuel pump
is stopped at Step 1?Go to Step 3. Go to Step 4.

6-1-120 ENGINE GENERAL INFORMATION AND DIAGNOSIS (H27 ENGINE)
3 1) Start engine and warm it up to normal oper-
ating temperature.
2) Keep it running at specified idle speed.
Is fuel pressure then within 210 – 260 kPa
(2.1 – 2.6 kg/cm
2, 29.8 – 37.0 psi)?Normal fuel pressure. Clogged vacuum passage
for fuel pressure regula-
tor or faulty fuel pressure
regulator.
4 Is there fuel leakage from fuel feed line hose,
pipe or joint?Fuel leakage from hose,
pipe or joint.Go to Step 10.
5 Was fuel pressure higher than spec. in Step 1? Go to Step 6. Go to Step 7.
6 1) Disconnect fuel return hose from fuel pipe
and connect new hose to it.
2) Put the other end of new return hose into
approved gasoline container.
3) Operate fuel pump.
Is specified fuel pressure obtained then?Restricted fuel return
hose or pipe.Faulty fuel pressure regu-
lator.
7 Was no fuel pressure applied in Step 1? Go to Step 8. Go to Step 9.
(Low pressure is mea-
sured.)
8 With fuel pump operated and fuel return hose
blocked by pinching it, is fuel pressure applied?Faulty fuel pressure regu-
lator.Shortage of fuel or fuel
pump or its circuit defec-
tive (Refer to “TABLE B-
1”).
9 1) Operate fuel pump.
2) With fuel return hose blocked by pinching it,
check fuel pressure.
Is it 450 kPa (4.5 kg/cm
2, 64.0 psi) or more?Faulty fuel pressure regu-
lator.Clogged fuel filter,
restricted fuel feed hose
or pipe, faulty fuel pump
or fuel leakage from hose
connection in fuel tank.
10 1) Disconnect fuel return hose from fuel pipe
and connect new hose to it.
2) Put the other end of new return hose into
approved gasoline container.
3) Check again if specified fuel pressure is
retained.
While doing so, does fuel come out return
hose?Faulty fuel pressure regu-
lator.Fuel leakage from injec-
tor, faulty fuel pump
(faulty check valve in fuel
pump) or fuel leakage
from fuel pressure regula-
tor diaphragm. Step Action Yes No

ENGINE GENERAL INFORMATION AND DIAGNOSIS (H27 ENGINE) 6-1-121
Table B-4 Idle Air Control System Inspection
WIRING DIAGRAM
INSPECTION
1. Throttle body 3. ECM (PCM) 5. Main fuse
2. Idle air control valve 4. Sensed information 6. Main relay
Step Action Yes No
1 Check engine idle speed and IAC duty
referring to “IDLE SPEED/IAC DUTY
INSPECTION” in Section 6E2.
Is idle speed/IAC duty within specifica-
tion?Go to Step 2. Go to Step 3.
2 Is engine idle speed kept specified speed
even with headlights turned ON?System is in good condition. Go to Step 3.

6-1-122 ENGINE GENERAL INFORMATION AND DIAGNOSIS (H27 ENGINE)
3 Check IAC valve referring to “IAC VALVE
INSPECTION” in Section 6E2.
Is check result as specified?Go to Step 4. IAC valve malfunction, “BLU/
BLK”, “LT GRN/BLK”, “PPL/
BLK”, “GRY/BLU” or “PPL/
YEL” wire open or short or
poor coupler connection.
If all above are OK, substi-
tute a known-good ECM
(PCM) and recheck.
4 Was idle speed within specification in
Step 1?Check for following :
FIA valve, Vacuum leaks, air inhal-
ing, EVAP canister purge control
system, accessory engine load,
stuck of PCV valve, clog of idle air
passage, MAF sensor, TP sensor,
ECT sensor, EGR valve malfunc-
tion (leakage from valve seat), A/C
signal, transmission range switch
signal and power steering switch
signal.Go to Step 5.
5 Was idle speed higher than specification
in Step 1?Go to Step 6. Go to Step 8.
6 Check A/C (input) signal circuit referring
to Step 1 of “Table B-5”. (A/C signal can
be also checked by using SUZUKI scan
tool.)
Is it in good condition?Go to Step 7. A/C signal circuit open or
short, or A/C system mal-
function.
7 Was IAC duty less than about 2% in Step
1 of this table?
Check FIA valve.
Check abnormal air inhaling from
intake manifold, throttle body, PCV
valve and EVAP canister purge
control system.Check TP sensor (closed
throttle position) and ECT
sensor for performance.
If sensors are OK, substitute
a known-good ECM (PCM)
and recheck.
8 Check transmission range switch signal
referring to “INSPECTION OF ECM
(PCM) AND ITS CIRCUIT” in this section.
Is check result satisfactory?Go to Step 9. Transmission range switch
malfunction or its circuits
open or short.
9 Was IAC duty more than about 30% in
Step 1 of this table?Check parts or system which can
cause engine low idle.
Check FIA valve.
Air inhaling from between throttle
body and MAF sensor, EGR valve
malfunction (leakage from valve
seat), accessory engine load, clog
of idle air passage and etc.Substitute a known-good
ECM (PCM) and recheck. Step Action Yes No

ENGINE GENERAL INFORMATION AND DIAGNOSIS (H27 ENGINE) 6-1-123
Table B-5 A/C Signal Circuits Inspection (If Equipped)
WIRING DIAGRAM
INSPECTION
1. A/C control module (amplifier)
2. ECM (PCM)
Step Action Yes No
1 Check A/C Signal Circuit.
1) Check voltage at terminal E61-17 with ignition
switch ON.
A/C signal circuit specification :
A/C switch and/or heater blower switch OFF (A/
C is not operating) : 10 – 14 V
Both A/C switch and heater blower switch ON :
0 – 1.5 V
Are check result as specified?Go to Step 2.“YEL/BLK” circuit open or
short, Evaporative tem-
perature is below 1°C
(34°F) or faulty A/C sys-
tem.
2 Check A/C Cut Signal Circuit.
1) Check voltage at terminal E61-8.
A/C cut signal specification :
While engine running and A/C switch and/or
heater blower switch OFF
(A/C is not operating) : 0 – 1.5 V
While engine running at idle speed and both A/
C switch and heater blower switch ON
(A/C is operating) : 10 – 14 V
Are check result as specified?A/C control signal cir-
cuits are in good con-
dition.“GRY/WHT” circuit open
or short, Poor perfor-
mance of ECT sensor, TP
sensor, Engine start sig-
nal inputted or A/C ampli-
fier malfunction.
If none of the above
exists, substitute a
known-good ECM (PCM)
and recheck.

6-1-124 ENGINE GENERAL INFORMATION AND DIAGNOSIS (H27 ENGINE)
Table B-6 A/C Condenser Fan Motor Relay Control System Inspection (If
Equipped)
WIRING DIAGRAM
INSPECTION
1. To ignition switch 3. A/C fuse 5. A/C condenser fan motor
2. Main fuse 4. A/C condenser fan motor relay 6. ECM (PCM)
WARNING:
Keep hands, tools, and clothing away from A/C condenser fan to help prevent personal injury. This
fan is electric and can come on whether or not the engine is running. The fan can start automatically
in response to the ECT sensor with the ignition switch in the “ON” position.
Step Action Yes No
1 1) Check DTC referring to “DTC CHECK” in this sec-
tion.
Is there any malfunction DTC?Go to applicable DTC
Diag. Flow Table.Go to Step 2.
2 1) Check A/C condenser fan for operation.
A/C condenser fan should be operated under follow-
ing condition A or B only.
A : When engine is running and A/C is operating.
B : When engine coolant temp. is 113°C (235°F) or
more with ignition switch ON.
Is check result as specified?This system is in
good condition.Go to Step 3.
3 1) Remove ECM (PCM) cover.
2) Check voltage between E61-22 terminal of ECM
(PCM) connected coupler and ground.
Other than conditions A and B in Step 2 :
10 – 14 V
Under condition A or B in Step 2 :
0 – 1 V
Is check result as specified?Fuse blown, “RED”,
“RED/BLK” or “RED/
BLU” circuit open,
malfunction of con-
denser fan motor or
relay.“YEL/GRN” circuit
open, “YEL/BLU” cir-
cuit open or short, or
relay malfunction.
If above are OK, sub-
stitute a known-good
ECM (PCM) and
recheck.