2001 SUZUKI GRAND VITARA engine start circuit

6-1-16 ENGINE GENERAL INFORMATION AND DIAGNOSIS (H27 ENGINE)
Malfunction Indicator Lamp (MIL) Check
1) Turn ON ignition switch (but the engine at stop) and check
that MIL (1) lights.
If MIL does not light up, go to “Diagnostic Flow Table A-1” for
troubleshooting.
2) Start engine and check that MIL turns OFF.
3) If MIL remains ON, and no DTC is stored in ECM (PCM), go
to “Diagnostic Flow Table A-2” for troubleshooting.
Diagnostic Trouble Code (DTC) Check
[Using SUZUKI scan tool]
1) Prepare generic scan tool or SUZUKI scan tool (2).
2) With ignition switch OFF, connect it to data link connector
(DLC) (3) located on underside of instrument panel at
driver’s seat side.
Special tool
(A) : SUZUKI scan tool
3) Turn ignition switch ON and confirm that MIL lights.
4) Read DTC and freeze frame data according to instructions
displayed on scan tool and print them or write them down.
Refer to scan tool operator’s manual for further details.
If communication between scan tool and ECM (PCM) is not
possible, check if scan tool is communicable by connecting it
to ECM (PCM) in another vehicle. If communication is possi-
ble in this case, scan tool is in good condition. Then check
data link connector and serial data line (circuit) in the vehicle
with which communication was not possible.
5) After completing the check, turn ignition switch off and dis-
connect scan tool from data link connector.

ENGINE GENERAL INFORMATION AND DIAGNOSIS (H27 ENGINE) 6-1-21
For A/T system (Refer to Section 7B1 for diagnosis)
P0505Idle air control system mal-
functionDifference between desired idle speed
and actual idle speed continues to
exceed specified value for longer than
specified time.2 driving
cyclesNot
applicable
P0601
(No.71)Internal control module mem-
ory check sum errorData write error (or check sum error)
when written into ECM1 driving
cycle1 driving
cycle
P1408Manifold absolute pressure
sensor circuit malfunctionManifold absolute pressure sensor
output voltage is higher or lower than
specified value (or sensor circuit
shorted to ground or open).2 driving
cyclesNot
applicable
P1450Barometric pressure sensor
circuit malfunctionBarometric pressure is lower or higher
than specification.1 driving
cycleNot
applicable
P1451Barometric pressure sensor
performance problemDifference between intake manifold
pressure and barometric pressure is
larger than specification.2 driving
cyclesNot
applicable
P1500Engine starter signal circuit
malfunctionEngine starts with no starter signal or
signal input during long period after
start.2 driving
cyclesNot
applicable
P1510ECM back-up power supply
malfunctionNo back-up power after starting
engine.1 driving
cycleNot
applicable DTC NO. DETECTED ITEMDETECTING CONDITION
(DTC will set when detecting : )MIL
(vehicle
without
monitor
connector)MIL
(vehicle
with
monitor
connector)
DTC NO. DETECTED ITEMDETECTING CONDITION
(DTC will set when detecting : )MIL
(vehicle
without
monitor
connector)MIL
(vehicle
with
monitor
connector)
P0705
(No.72)Transmission range switch cir-
cuit malfunctionMultiple signals inputted simulta-
neously or P, R, N, D, 2 or L range sig-
nal not inputted while running at
60km/h or more.2 driving
cyclesNot
applicable
P0715
(No.76)Input speed sensor circuit
malfunctionInput speed sensor signal is lower
than specification while running.2 driving
cyclesNot
applicable
P0720
(No.75)Output speed sensor circuit
malfunctionOutput speed sensor signal not input-
ted while VSS signal being inputted.2 driving
cyclesNot
applicable
P0741TCC (lock-up) solenoid perfor-
mance or stuck offActual TCC operation does not agree
with ON/OFF control from PCM to
TCC.2 driving
cyclesNot
applicable
P0743
(No.65)
(No.66)TCC (lock-up) solenoid electri-
calMonitor signal OFF is detected when
TCC control solenoid is ON or monitor
signal ON is detected when it is OFF.1 driving
cycleNot
applicable
P0751Shift solenoid A (#1) perfor-
mance or stuck offGear change control from PCM to A/T
does not agree with actual gear posi-
tion of A/T.2 driving
cyclesNot
applicable

ENGINE GENERAL INFORMATION AND DIAGNOSIS (H27 ENGINE) 6-1-23
Fail-Safe Table
When any of the following DTCs is detected, ECM (PCM) enters fail-safe mode as long as malfunction continues
to exist but that mode is canceled when ECM (PCM) detects normal condition after that.
DTC NO. TROUBLE AREA FAIL SAFE OPERATION
P0100
(No.33, 34)MAF SENSOR• Injector drive time (fuel injection volume) is determined according to
throttle valve opening and engine speed.
• EGR valve stops.
• Air flow of IAC valve is limited.
P0110
(No.23, 25)IAT SENSOR Each control is performed on the basis of 22.1°C intake air temp.
P0115
(No.14, 15)ECT SENSOR• Each control except 4-A/T is performed on the basis of 29.9°C engine
coolant temp.
• 4-A/T control is performed assuming 31°C (engine warmed up) or
higher after 15 min. from engine start.
P0120
(No.21, 22)TP SENSOR• Each control except 4-A/T is performed on the basis of 124.5° throttle
valve opening.
• 4-A/T control is performed on the basis of 0° throttle valve opening.
P0460 FUEL LEVEL SENSOR Each control is performed in the basis of full fuel level.
P0500VEHICLE SPEED
SENSORAir flow of IAC valve is limited.
P1450BAROMETRIC
PRESSURE SENSOREach control is performed based on 760 mmHg barometric pressure.
P0705 TR SWITCH A/T control is performed in priority order of L, 2, N, D, R and P.
P0720OUTPUT SPEED
SENSOR CIRCUIT
MALFUNCTIONA/T control is performed by using signal from VSS.
P0753SHIFT SOLENOID
A (#1)• A/T control using 3rd gear is performed when D range, 1st, or 2nd
gear is used.
• TCC solenoid OFF
P0758SHIFT SOLENOID
B (#2)• A/T control using 4th gear is performed when D range, 2nd or 3rd
gear is used.
• When both shift solenoids A (#1) and B (#2) failed simultaneously,
A/T control using 4th gear is always performed in D range.
• TCC solenoid OFF
P0743TCC (Lock-up)
SOLENOIDTCC (Lock-up) solenoid OFF

ENGINE GENERAL INFORMATION AND DIAGNOSIS (H27 ENGINE) 6-1-31
Engine Diagnosis Table
Perform troubleshooting referring to following table when ECM (PCM) has detected no DTC and no abnormality
has been found in visual inspection and engine basic inspection previously.
Condition Possible Cause Correction
Hard starting
(Engine cranks OK)Faulty idle air control system “DIAG. FLOW TABLE B-4” in this
section.
Faulty ECT sensor or MAF sensor ECT sensor or MAF sensor in Sec-
tion 6E2.
Faulty ECM (PCM) Inspection of ECM (PCM) and its
circuit in this section.
Low compression Compression check in Section
6A2.
Faulty hydraulic valve lash adjuster Valve lash adjuster in Section 6A2.
Compression leak from valve seat Valves inspection in Section 6A2.
Sticky valve stem Valves inspection in Section 6A2.
Weak or damaged valve springs Valves spring inspection in Section
6A2.
Compression leak at cylinder head gasket Cylinder head inspection in Section
6A2.
Sticking or damaged piston ring Piston ring inspection in Section
6A2.
Worn piston, ring or cylinder Cylinders, pistons and piston rings
inspection in Section 6A2.
Malfunctioning PCV valve PCV system inspection in Section
6E2.
Engine has no power
Engine overheating Refer to “OVERHEATING” in this
table.
Defective spark plug Spark plugs in Section 6F2.
Faulty ignition coil with ignitor Ignition coil in Section 6F2.
Fuel pressure out of specification
(dirty fuel filter, dirty or clogged fuel hose or
pipe, malfunctioning fuel pressure regulator,
malfunctioning fuel pump)“DIAG. FLOW TABLE B-3” in this
section.
Maladjusted TP sensor installation angle TP sensor in Section 6E2.
Faulty EGR system “DTC P0400 DIAG. FLOW TABLE”
in this section.
Faulty injector Fuel injector in Section 6E2.
Faulty TP sensor, ECT sensor or MAF sensor TP sensor, ECT sensor or MAF
sensor in Section 6E2.
Faulty ECM (PCM) Inspection of ECM (PCM) and its
circuit in this section.
Low compression Refer to the same item in “HARD
STARTING” of this table.
Dragging brakes Diagnosis in Section 5.
Slipping clutch Diagnosis in Section 7C1.

6-1-32 ENGINE GENERAL INFORMATION AND DIAGNOSIS (H27 ENGINE)
Improper engine idling
or engine fails to idleFaulty spark plug Spark plugs in Section 6F2.
Faulty ignition coil with ignitor Ignition coil in Section 6F2.
Fuel pressure out of specification “DIAG. FLOW TABLE B-3” in this
section.
Engine overheating Refer to “OVERHEATING” in this
table.
Maladjusted TP sensor installation angle if
adjustableTP sensor in Section 6E2.
Faulty idle air control system “DIAG. FLOW TABLE B-4” in this
section.
Faulty FIA (fast idle air) valve FIA valve in Section 6E2.
Faulty evaporative emission control system EVAP control system in Section
6E2.
Faulty EGR system “DTC P0400 DIAG. FLOW TABLE”
in this section.
Faulty injector Fuel injection in Section 6E2.
Faulty ECT sensor, TP sensor or MAF sensor ECT sensor, TP sensor or MAF
sensor in Section 6E2.
Faulty ECM (PCM) Inspection of ECM (PCM) and its
circuit in this section.
Low compression Refer to the same item in “HARD
STARTING” of this table.
Malfunctioning PCV valve PCV system inspection in Section
6E2.
Engine hesitates
(Momentary lack of
response as the accel-
erator is depressed.
Can occur at all vehi-
cle speeds.
Usually most severe
when first trying to
make the vehicle
move, as from a stop
sign.)Spark plug faulty or plug gap as out of adjust-
mentSpark plugs in Section 6F2.
Fuel pressure out of specification
(clogged fuel filter, faulty fuel pressure regula-
tor, clogged fuel filter, hose or pipe)“DIAG. FLOW TABLE B-3” in this
section.
Engine overheating Refer to “OVERHEATING” in this
table.
Faulty EGR system “DTC P0400 DIAG. FLOW TABLE”
in this section.
Faulty injector Fuel injector in Section 6E2.
Faulty TP sensor, ECT sensor or MAF sensor TP sensor, ECT sensor or MAF
sensor in Section 6E2.
Faulty ECM (PCM) Inspection of ECM (PCM) and its
circuit in this section.
Low compression Refer to the same item in “HARD
STARTING” of this table. Condition Possible Cause Correction

6-1-34 ENGINE GENERAL INFORMATION AND DIAGNOSIS (H27 ENGINE)
Poor gasoline mileage
Faulty spark plug (improper gap, heavy depos-
its, and burned electrodes, etc.)Spark plugs in Section 6F2.
Fuel pressure out of specification “DIAG. FLOW TABLE B-3” in this
section.
Faulty TP sensor, ECT sensor or MAF sensor TP sensor, ECT sensor or MAF
sensor in Section 6E2.
Faulty EGR system “DTC P0400 DIAG. FLOW TABLE”
in this section.
Faulty injector Fuel injector in Section 6E2.
Faulty ECM (PCM) Inspection of ECM (PCM) and its
circuit in this section.
Low compression Refer to the same item in “HARD
STARTING” of this table.
Poor valve seating Valves inspection in Section 6A2.
Dragging brakes Diagnosis in Section 5.
Slipping clutch Diagnosis in Section 7C1.
Thermostat out of order Thermostat in Section 6B.
Improper tire pressure Diagnosis in Section 3.
Excessive engine oil
consumptionSticky piston ring Piston cleaning in Section 6A2.
Worn piston and cylinder Cylinders, pistons and piston rings
inspection in Section 6A2.
Worn piston ring groove and ring Pistons and piston rings inspection
in Section 6A2.
Improper location of piston ring gap Pistons installation in Section 6A2.
Worn or damaged valve stem seal Valves and cylinder head in Sec-
tion 6A2.
Worn valve stem Valves inspection in Section 6A2.
Low oil pressure
Improper oil viscosity Engine oil and oil filter change in
Section 0B.
Malfunctioning oil pressure switch Oil pressure switch inspection in
Section 8.
Clogged oil strainer Oil pan and oil pump strainer clean-
ing in Section 6A2.
Functional deterioration of oil pump Oil pump in Section 6A2.
Worn oil pump relief valve Oil pump in Section 6A2.
Excessive clearance in various sliding parts “INSPECTION” for each parts in
Section 6A2. Condition Possible Cause Correction

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) 6-1-43
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.