ignition switch SUZUKI GRAND VITARA 2001 2.G Workshop Manual

6-1-36 ENGINE GENERAL INFORMATION AND DIAGNOSIS (H27 ENGINE)
Inspection of PCM (ECM) and its Circuits
PCM (ECM) and its circuits can be checked at PCM (ECM) wiring
couplers by measuring voltage and resistance.
VOLTAGE CHECK
1) Remove PCM (ECM) cover from bracket referring to PCM
(ECM) REMOVAL.
2) Check voltage at each terminal of couplers connected.CAUTION:
PCM/ECM cannot be checked by itself. It is strictly pro-
hibited to connect voltmeter or ohmmeter to PCM (ECM)
with couplers disconnected from it.
NOTE:
As each terminal voltage is affected by the battery volt-
age, confirm that it is 11 V or more when ignition switch
is ON.
1. PCM (ECM)
2. PCM (ECM) connector (Viewed from harness side)

ENGINE GENERAL INFORMATION AND DIAGNOSIS (H27 ENGINE) 6-1-37
TERMINAL CIRCUIT NORMAL VOLTAGE CONDITION
E61-1Power source for CO adjusting
resistor (if equipped)10 – 14 V Ignition switch ON
E61-2 Power source for back up 10 – 14 V Ignition switch ON and OFF
E61-3 – – –
E61-4Cruise control module
(throttle opening signal)
(if equipped)Ignition switch ON, Voltage varies as specified at figure in
cruise control diagnosis of Section 8E while throttle valve is
opened gradually.
E61-5Duty output terminal
(vehicle with monitor connector)0 – 1 V Ignition switch ON
E61-6 Tachometer 0 – 1 V Ignition switch ON, engine stops
E61-7Malfunction indicator lamp
(“SERVICE ENGINE SOON” lamp)0 – 2.5 V Ignition switch ON, engine stops
10 – 14 V Engine running
E61-8 A/C cut signal (if equipped)0 – 1.5 V A/C is not operating
10 – 14 V A/C is operating
E61-9 Main relay10 – 14 V Ignition switch OFF
0 – 2 VIgnition switch ON or for 4 seconds
after ignition switch OFF
E61-10 CO adjusting resistor (if equipped) – –
E61-11 – – –
E61-12Data link connector (5V)
(Vehicle with monitor connector)4 – 6 V Ignition switch ON
E61-13 Data link connector (12V) 10 – 14 V Scan tool not connected to DLC
E61-14Test switch terminal
(Vehicle with monitor connector)10 – 14 V Ignition switch ON
E61-15 Rear defogger switch (if equipped)0 – 1.5 VIgnition switch ON, rear defogger
switch OFF
10 – 14 VIgnition switch ON, rear defogger
switch
E61-16 Heater blower switch10 – 14 VIgnition switch ON, heater blower
switch OFF
0 – 1.5 VIgnition switch ON, heater blower
switch ON
E61-17 A/C signal (if equipped)10 – 14 VIgnition switch ON, A/C switch or
heater blower switch OFF
0 – 1 VIgnition switch ON, A/C switch ON
and heater blower switch ON
E61-18 – – –
E61-19 “4WD” lamp0 – 1 VIgnition switch ON, Transfer lever :
4H or 4L range
10 – 14 VIgnition switch ON, Transfer lever :
2H range
E61-20 “O/D OFF” lamp (A/T vehicle)0 – 1 VFor 4 sec. after ignition switch ON
or overdrive cut switch ON
10 – 14 VAfter 4 sec. from ignition switch ON
and overdrive cut switch OFF
E61-21 “POWER” lamp (A/T vehicle)0 – 1 VIgnition switch ON, P/N change
switch : POWER mode
10 – 14 VIgnition switch ON, P/N change
switch : NORMAL mode

6-1-38 ENGINE GENERAL INFORMATION AND DIAGNOSIS (H27 ENGINE)
E61-22A/C condenser fan motor relay
(if equipped)10 – 14 VIgnition switch ON, A/C not oper-
ated and Engine coolant temp. :
less than 113°C, 235°F
E61-23 Fuel pump relay0 – 2.5 VFor 3 sec. after ignition switch ON
or while engine running
10 – 14 VAfter 3 sec. from ignition switch ON
with engine stopped
E61-24Ground for CO adjusting resistor
(if equipped)––
E61-25 – – –
E61-26 – – –
E61-27 – – –
E61-28 Fuel level sensor 0 – 6 VIgnition switch ON
Voltage depends on fuel level
E61-29Diag. switch terminal
(vehicle with monitor connector)10 – 14 V Ignition switch ON
E61-30 ABS control module 10 – 14 V Ignition switch ON
E61-31Power/Normal change switch
(A/T vehicle)0 – 1 VIgnition switch ON, P/N change
switch : POWER mode
10 – 14 VIgnition switch ON, P/N change
switch : NORMAL mode
E61-32 Lighting switch0 – 1 VIgnition switch ON, lighting switch
OFF
10 – 14 VIgnition switch ON, lighting switch
ON
E61-33 Overdrive cut switch (A/T vehicle)10 – 14 VIgnition switch ON, overdrive cut
switch released
0 – 1 VIgnition switch ON, overdrive cut
switch pressed
E61-34 Stop lamp switch0 – 1 VBrake pedal released (switch OFF),
Ignition switch ON
10 – 14 VBrake pedal depressed (switch ON),
Ignition switch ON
E61-35 Cruise control module (if equipped) 10 – 14 V Ignition switch ON
C51-3-1 Intake air temp. sensor 2.2 – 3.0 VIgnition switch ON, Sensor ambient
temp. : 20°C, 68°F
C51-3-2 Engine coolant temp. sensor 0.5 – 0.9 VIgnition switch ON, Engine coolant
temp. : 80°C, 176°F
C51-3-3 Knock sensor About 2.5 VWith engine running at idle after
warned up
C51-3-4 Power source 10 – 14 V Ignition switch ON
C51-3-5 Ground for MAF sensor – –
C51-3-6 Ground – –
C51-3-7 4WD switch0 – 1 VIgnition switch ON, Transfer lever :
4H or 4L range
10 – 14 VIgnition switch ON, Transfer lever :
2H range
C51-3-8 Manifold absolute pressure sensor 3.3 – 4.3 V Ignition switch ON and engine stops TERMINAL CIRCUIT NORMAL VOLTAGE CONDITION

ENGINE GENERAL INFORMATION AND DIAGNOSIS (H27 ENGINE) 6-1-39
C51-3-9 Throttle position sensor0.5 – 1.2 VIgnition switch ON, Throttle valve at
idle position
3.4 – 4.7 VIgnition switch ON, Throttle valve at
full open position
C51-3-10 Mass air flow sensor1.0 – 1.6 V Ignition switch ON and engine stops
1.7 – 2.0 V With engine running at idle speed
C51-3-11Heated oxygen sensor-1 (bank 1)
(if equipped)Deflects between
over and under 0.45 VWhile engine running at 2,000 r/min.
for 1 min. or longer after warmed up
C51-3-12 Ground for TP sensor – –
C51-3-13 Power source for TP sensor
4.75 – 5.25 V Ignition switch ON
C51-3-14 Power source for MAP sensor
C51-3-15 Power source 10 – 14 V Ignition switch ON
C51-3-16 – – –
C51-3-17 Ground – –
C51-3-18Pressure switch in 4WD air pump
assembly10 – 14 VIgnition switch ON, Transfer lever :
4H or 4L range
0 – 1 VIgnition switch ON, Transfer lever :
2H range
C51-3-19 – – –
C51-3-20 Ignition switch 10 – 14 V Ignition switch ON
C51-3-21Heated oxygen sensor-1 (bank 2)
(if equipped)Deflects between over
and under 0.45 VWhile engine running at 2,000 r/min.
for 1 min. or longer after warmed up
C51-3-22Heated oxygen sensor-2 (bank 1)
(if equipped)Deflects between over
and under 0.45 VWhile engine running at 2,000 r/min.
for 1 min. or longer after warmed up
C51-3-23Heated oxygen sensor-2 (bank 2)
(if equipped)Deflects between over
and under 0.45 VWhile engine running at 2,000 r/min.
for 1 min. or longer after warmed up
C51-3-24 Ground for ECT sensor – –
C51-3-25 Ground for IAT sensor, MAP sensor – –
C51-3-26 Ground for CMP sensor – –
C51-1-1 Shift solenoid B (A/T vehicle) 0 – 1 V Ignition switch ON
C51-1-2 Shift solenoid A (A/T vehicle) 10 – 14 V Ignition switch ON
C51-1-3 – – –
C51-1-4 IAC valve (stepper motor coil 2) – –
C51-1-5 IAC valve (stepper motor coil 1) – –
C51-1-6Transmission range switch “R”
(A/T vehicle)10 – 14 VIgnition switch ON, selector lever :
“R” range
0 – 1 VIgnition switch ON, selector lever :
Other than “R”
C51-1-7Transmission range switch “P”
(A/T vehicle)10 – 14 VIgnition switch ON, selector lever :
“P” range
0 – 1 VIgnition switch ON, selector lever :
Other than “P” range
C51-1-8 TCC solenoid (A/T vehicle) 0 – 1 V Ignition switch ON
C51-1-9 4WD air pump assembly10 – 14 VIgnition switch ON, Transfer lever :
4H or 4L range
0 – 1 VIgnition switch ON, Transfer lever :
2H range TERMINAL CIRCUIT NORMAL VOLTAGE CONDITION

6-1-40 ENGINE GENERAL INFORMATION AND DIAGNOSIS (H27 ENGINE)
C51-1-10A/T input speed sensor (–)
(A/T vehicle)About 2.5 V Ignition switch ON
C51-1-11A/T input speed sensor (+)
(A/T vehicle)About 2.5 V Ignition switch ON
C51-1-12 Camshaft position sensor 1Deflects between
0 – 1 V and 4 – 6 VIgnition switch ON, crankshaft
turned slowly
C51-1-13 Camshaft position sensor 2Deflects between
0 – 1 V and 4 – 6 VIgnition switch ON, crankshaft
turned slowly
C51-1-14 Vehicle speed sensorDeflects between
0 – 1 V and over 4VIgnition switch ON, Rear right tire
turned slowly with rear left tire
locked
C51-1-15 EVAP canister purge valve 10 – 14 V Ignition switch ON
C51-1-16 IAC valve (stepper motor coil 4) – –
C51-1-17 IAC valve (stepper motor coil 3) – –
C51-1-18Transmission range switch “D”
(A/T vehicle)10 – 14 VIgnition switch ON, selector lever :
“D” range
0 – 1 VIgnition switch ON, selector lever :
Other than “D” range
C51-1-19Transmission range switch “N”
(A/T vehicle)10 – 14 VIgnition switch ON, selector lever :
“N” range
0 – 1 VIgnition switch ON, selector lever :
Other than “N” range
C51-1-20Shield wire ground for A/T output
speed sensor (A/T vehicle)––
C51-1-21Shield wire ground for A/T input
speed sensor (A/T vehicle)––
C51-1-22A/T output speed sensor (–)
(A/T vehicle)About 2.5 V Ignition switch ON
C51-1-23A/T output speed sensor (+)
(A/T vehicle)About 2.5 V Ignition switch ON
C51-1-24 Engine start signal10 – 14 V While engine cranking
0 – 1 V Other than above
C51-1-25 Power steering pressure switch10 – 14 V Ignition switch ON
0 – 1 VWith engine running at idle speed,
turning steering wheel to the right or
left as far as it stops
C51-1-26 4WD low switch0 – 1 VIgnition switch ON, Transfer lever :
4WD low range
10 – 14 VIgnition switch ON, Transfer lever :
4H or 2H range
C51-1-27Transmission range switch “L”
(A/T vehicle)10 – 14 VIgnition switch ON, selector lever :
“L” range
0 – 1 VIgnition switch ON, selector lever :
Other than “L” range
C51-1-28Transmission range switch “2”
(A/T vehicle)10 – 14 VIgnition switch ON, selector lever :
“2” range
0 – 1 VIgnition switch ON, selector lever :
Other than “2” range TERMINAL CIRCUIT NORMAL VOLTAGE CONDITION

ENGINE GENERAL INFORMATION AND DIAGNOSIS (H27 ENGINE) 6-1-41
C51-2-1 Fuel injector No.2
10 – 14 V Ignition switch ON
C51-2-2 Fuel injector No.1
C51-2-3 – – –
C51-2-4Heater of HO2S-1 (bank 1)
(if equipped)10 – 14 V Ignition switch ON
0 – 2 VAt specified idle speed after engine
warmed up
C51-2-5Heater of HO2S-1 (bank 2)
(if equipped)10 – 14 V Ignition switch ON
0 – 2 VAt specified idle speed after engine
warmed up
C51-2-6 – – –
C51-2-7 Ground – –
C51-2-8 Fuel injector No.4
10 – 14 V Ignition switch ON
C51-2-9 Fuel injector No.3
C51-2-10 – – –
C51-2-11 – – –
C51-2-12EGR valve (stepper motor coil 4)
(if equipped)0 – 1 V
Ignition switch ON C51-2-13EGR valve (stepper motor coil 3)
(if equipped)10 – 14 V
C51-2-14EGR valve (stepper motor coil 2)
(if equipped)10 – 14 V
C51-2-15EGR valve (stepper motor coil 1)
(if equipped)0 – 1 V
C51-2-16Heater of HO2S-2 (bank 1)
(if equipped)10 – 14 V Ignition switch ON
0 – 1 VAt specified idle speed after engine
warmed up
C51-2-17Heater of HO2S-2 (bank 2)
(if equipped)10 – 14 V Ignition switch ON
0 – 1 VAt specified idle speed after engine
warmed up
C51-2-18 – – –
C51-2-19Crankshaft position sensor (+)
(if equipped)––
C51-2-20Crankshaft position sensor (–)
(if equipped)––
C51-2-21 Fuel injector No.6
10 – 14 V Ignition switch ON
C51-2-22 Fuel injector No.5
C51-2-23 Ignition coil assembly for No.6 – –
C51-2-24 Ignition coil assembly for No.5 – –
C51-2-25 Ignition coil assembly for No.4 – –
C51-2-26 Ignition coil assembly for No.3 – –
C51-2-27 Ignition coil assembly for No.2 – –
C51-2-28 Ignition coil assembly for No.1 – –
C51-2-29 – – –
C51-2-30Ground for CKP sensor shield wire
(if equipped)–– TERMINAL CIRCUIT NORMAL VOLTAGE CONDITION

6-1-42 ENGINE GENERAL INFORMATION AND DIAGNOSIS (H27 ENGINE)
RESISTANCE CHECK
1) Disconnect couplers (1) from ECM/PCM with ignition switch
OFF.
2) Check resistance between each pair of terminals of discon-
nected couplers (1) as listed in following table. CAUTION:
Never touch terminals of ECM/PCM itself or connect volt-
meter or ohmmeter (2).
CAUTION:
Be sure to connect ohmmeter (2) probe from wire har-
ness side of coupler.
Be sure to turn OFF ignition switch for this check.
Resistance in table represents that when parts temper-
ature is 20°C (68°F).
TERMINALS CIRCUIT STANDARD
RESISTANCECONDITION
E61-9 and E61-2 Main relay 79 – 95 Ω–
E61-22 and C51-3-20 A/C fan motor relay (if equipped) 75 – 110 ΩBattery disconnected
and ignition switch ON
E61-23 and C51-3-20 Fuel pump relay 79 – 95 Ω–
C51-3-6 and Body ground Ground Continuity –
C51-3-17 and Body ground Ground Continuity –
C51-1-1 and Body ground Shift solenoid B (A/T) 11 – 15 Ω–
C51-1-2 and Body ground Shift solenoid A (A/T)
C51-1-4 and C51-3-4 IAC valve (stepper motor coil 2) 25.5 – 33.5 Ω–
C51-1-5 and C51-3-4 IAC valve (stepper motor coil 1)
C51-1-8 and Body ground TCC solenoid (A/T) 11 – 15 Ω–
C51-1-15 and C51-3-4 EVAP canister purge valve 28 – 35 Ω–
C51-1-16 and C51-3-4 IAC valve (stepper motor coil 4) 25.5 – 33.5 Ω–
C51-1-17 and C51-3-4 IAC valve (stepper motor coil 3)
C51-2-1 and C51-3-4 Fuel injector No.2 13 – 16 Ω–
C51-2-2 and C51-3-4 Fuel injector No.1
C51-2-4, C51-2-5 and E61-9 Heater of HO2S-1 5.0 – 6.4 Ω–
C51-2-7 and Body ground Ground Continuity –
C51-2-8 and C51-3-4 Fuel injector No.4 13 – 16 Ω–
C51-2-9 and C51-3-4 Fuel injector No.3
C51-2-12 and C51-3-4 EGR valve (stepper motor coil 4) 20 – 24 Ω–
C51-2-13 and C51-3-4 EGR valve (stepper motor coil 3)
C51-2-14 and C51-3-4 EGR valve (stepper motor coil 2)
C51-2-15 and C51-3-4 EGR valve (stepper motor coil 1)
C51-2-16, C51- 2-17 and
E61-9Heater of HO2S-2 11.7 – 14.3 Ω–
C51-2-21 and C51-3-4 Fuel injector No.6
13 – 16 Ω–
C51-2-22 and C51-3-4 Fuel injector No.5

ENGINE GENERAL INFORMATION AND DIAGNOSIS (H27 ENGINE) 6-1-43
Table A-1 Malfunction Indicator Lamp Circuit Check – Lamp Does Not Come
“ON” or Dims at Ignition Switch ON (But Engine at Stop)
WIRING DIAGRAM
CIRCUIT DESCRIPTION
When the ignition switch is turned ON, ECM causes the main relay to turn ON (close the contact point). Then,
ECM being supplied with the main power, turns ON the malfunction indicator lamp (MIL). When the engine
starts to run and no malfunction is detected in the system, MIL goes OFF but if a malfunction was or is detected,
MIL remains ON even when the engine is running.
INSPECTION
1. MIL
2. To ignition switch
3. Main fuse
4. Main relay
5. ECM (PCM)
6. Monitor connector (if equipped)
Step Action Yes No
1 MIL power supply check :
1) Turn ignition switch ON.
Do other indicator/warning lights in combination
meter comes ON?Go to Step 2. “IG METER” fuse blown,
main fuse blown, Ignition
switch malfunction, “BLK/
WHT” circuit between “IG
METER” fuse and combi-
nation meter or poor cou-
pler connection at
combination meter.

6-1-44 ENGINE GENERAL INFORMATION AND DIAGNOSIS (H27 ENGINE)
Table A-2 Malfunction Indicator Lamp Circuit Check – Lamp Remains “ON”
after Engine Starts
WIRING DIAGRAM/CIRCUIT DESCRIPTION
Refer to TABLE A-1.
INSPECTION
2 ECM power and ground circuit check :
Does engine start?Go to Step 3. Go to “TABLE A-3 ECM
(PCM) POWER AND
GROUND CIRCUIT
CHECK” in this section.
If engine is not cranked,
go to “DIAGNOSIS” in
Section 6G.
3 MIL circuit check :
1) Turn ignition switch OFF and disconnect
connectors from ECM.
2) Check for proper connection to ECM at ter-
minal E61-7.
3) If OK, then using service wire, ground termi-
nal E61-7 in connector disconnected.
Does MIL turn on at ignition switch ON?Substitute a known-good
ECM (PCM) and recheck.Bulb burned out or “PPL/
YEL” wire circuit open. Step Action Yes No
Step Action Yes No
1 DTC check :
1) With ignition switch OFF, install scan tool.
2) Start engine and check DTC.
Is there any malfunction DTC (s).Go to Step 2 of “ENGINE
DIAG. FLOW TABLE” in
this section.Go to Step 2.
2 MIL circuit check :
1) With ignition switch OFF, disconnect cou-
plers from ECM (PCM).
Does MIL turn ON at ignition switch ON?“PPL/YEL” wire shorted to
ground circuit.Substitute a known-good
ECM (PCM) and recheck.

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.