2001 SUZUKI GRAND VITARA start circuit

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.

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.

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)