2001 SUZUKI GRAND VITARA ignition system

6-1-14 ENGINE GENERAL INFORMATION AND DIAGNOSIS (H27 ENGINE)
STEP 6. AND 7. RECHECKING AND RECORD OF DTC
Refer to “DTC Check” in this section for checking procedure.
STEP 8. ENGINE BASIC INSPECTION AND ENGINE DIAGNOSIS TABLE
Perform basic engine check according to the “ENGINE BASIC INSPECTION FLOW TABLE” first. When the end
of the flow table has been reached, check the parts of the system suspected as a possible cause referring to
“ENGINE DIAGNOSIS TABLE” and based on symptoms appearing on the vehicle (symptoms obtained through
steps of customer complaint analysis, trouble symptom confirmation and/or basic engine check) and repair or
replace faulty parts, if any.
Engine Basic Inspection Flow Table
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 battery voltage.
Is it 11 V or more?Go to Step 3. Charge or replace battery.
3 Is engine cranked? Go to Step 4. Go to “DIAGNOSIS” in
Section 6H.
4 Does engine start? Go to Step 5. Go to Step 7.
5 Check engine idle speed/IAC duty referring to
“IDLE SPEED/IAC DUTY INSPECTION” in
Section 6E2.
Is check result as specified?Go to Step 6. Go to “ENGINE DIAGNO-
SIS TABLE” in this sec-
tion.
6 Check ignition timing referring to “IGNITION
TIMING INSPECTION” in Section 6F2.
Is check result as specified?Go to “ENGINE DIAGNO-
SIS TABLE” in this sec-
tion.Adjust ignition timing.
7 Check fuel supply as follows :
1) Check to make sure that enough fuel is
filled in fuel tank.
2) Turn ON ignition switch for 3 seconds and
then OFF.
Repeat this a few times.
Is fuel return pressure (returning sounds) felt
from fuel return hose when ignition switch is
turned ON?Go to Step 9. Go to Step 8.
8 Check fuel pump for operating.
1) Was fuel pump operating sound heard from
fuel filler for about 3 seconds after ignition
switch ON and stop?Go to “DIAG. FLOW
TABLE B-3” in this sec-
tion.Go to “DIAG. FLOW
TABLE B-1” in this sec-
tion.
9 Check ignition spark referring to “IGNITION
SPARK TEST” in Section 6E2.
Is it in good condition?Go to Step 10. Go to “DIAGNOSIS” in
Section 6F2.
10 Check fuel injector referring to “Fuel INJECTOR
INSPECTION” in Section 6E2.
Is it in good condition?Go to “ENGINE DIAGNO-
SIS TABLE” in this sec-
tion.Go to “DIAG. FLOW
TABLE B-2” in this sec-
tion.

ENGINE GENERAL INFORMATION AND DIAGNOSIS (H27 ENGINE) 6-1-25
INJ PULSE WIDTH B2 At specified idle speed with no load after
warming up.2.0 – 3.3 msec
✱
At 2500 r/min with no load after warming up. 2.2 – 3.2 msec
THROTTLE POS
(Absolute Throttle Posi-
tion)With ignition switch ON/warmed up engine
stopped, accelerator pedal released9.8 – 18.2 %
With ignition switch ON/warmed up engine
stopped, accelerator pedal depressed fully72 – 87.2 %
TP SENSOR VOLT
(TP Sensor Output Volt-
age)With ignition switch ON/warmed up engine
stopped, accelerator pedal released0.49 – 0.91 V
✱
With ignition switch ON/warmed up engine
stopped, accelerator pedal depressed fully.3.76 – 4.36 V
O2S B1 S1
(HO2S-1 Output Voltage)At specified idle speed after warming up
0.05 – 0.95 V
O2S B1 S2
(HO2S-2 Output Voltage)When engine is running at 2000 r/min. for 3
min or longer after warming up.0.05 – 0.95 V
O2S B2 S1
(HO2S-2 Output Voltage)When engine is running at 2000 r/min. for 3
min or longer after warming up.0.05 – 0.95 V
O2S B2 S2
(HO2S-2 Output Voltage)When engine is running at 2000 r/min. for 3
min or longer after warming up.0.05 – 0.95 V
FUEL SYSTEM B1
(Fuel System Status)At specified idle speed after warming up.
Closed✱
FUEL SYSTEM B2
(Fuel System Status)At specified idle speed after warming up.
Closed
CALC LOAD
(Calculated Load Value)At specified idle speed with no load after
warming up.10 – 25 %
At 2500 r/min with no load after warming up. 14 – 23 %
TOTAL FT TRIM B1 At specified idle speed after warming up. –30 – +30 %✱
TOTAL FT TRIM B2 At specified idle speed after warming up. –30 – +30 %
MAP At specified idle speed after warming up. 25 – 35 kPa
CANIST PRG DUTY
(EVAP Canister Purge
Flow Duty)At specified idle speed after warming up.
0 %✱
VEHICLE SPEED. At stop. 0 km/h 0 MPH
FUEL CUT When engine is at fuel cut condition ON
✱
Other than fuel cut condition OFF
EGR VALVE At specified idle speed after warming up 0 %✱
BLOWER FAN Ignition switch ON, blower fan switch ON ON
✱
Ignition switch ON, blower fan switch OFF OFF
A/C CONDENSER FAN Ignition switch ON, A/C not operating OFF
✱
Ignition switch ON, A/C operating ON
PSP SWITCH Engine running at idle speed and steering
wheel at straight ahead positionOFF
✱
Engine running at idle speed and steering
wheel turned to the right or left as far as it
stopsON
A/C SWITCH
(if equipped)When A/C not operating OFF
✱
When A/C operating ON SCAN TOOL DATA CONDITIONNORMAL CONDITION/
REFERENCE VALUEOTHER

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

ENGINE GENERAL INFORMATION AND DIAGNOSIS (H27 ENGINE) 6-1-33
Surges
(Engine power varia-
tion under steady
throttle or cruise.
Feels like the vehicle
speeds up and down
with no change in the
accelerator pedal.)Defective spark plug
(excess carbon deposits, improper gap, and
burned electrodes, etc.)Spark plugs in Section 6F2.
Variable fuel pressure
(clogged fuel filter, kinky or damaged fuel hose
and line, faulty fuel pressure regulator)“DIAG. FLOW TABLE B-3” in this
section.
Faulty EGR system “DTC P0400 DIAG. FLOW TABLE”
in this section.
Faulty MAF sensor MAF sensor in Section 6E2.
Faulty injector Fuel injector in Section 6E2.
Faulty ECM (PCM) Inspection of ECM (PCM) and its
circuit in this section.
Excessive detonation
(The engine makes
sharp metallic knocks
that change with throt-
tle opening. Sounds
like pop corn pop-
ping.)Engine overheating Refer to “OVERHEATING” in this
table.
Faulty spark plug Spark plugs in Section 6F2.
Improper ignition timing Ignition timing in Section 6F2.
Clogged fuel filter and fuel lines Fuel pressure check in Section
6E2.
Faulty EGR system “DTC P0400 DIAG. FLOW TABLE”
in this section.
Faulty ECT sensor or MAF sensor ECT sensor or MAF sensor in Sec-
tion 6E2.
Faulty injector Fuel injector in Section 6E2.
Faulty ECM (PCM) Inspection of ECM (PCM) and its
circuit in this section.
Excessive carbon deposits in combustion
chamberPiston and cylinder head cleaning
in Section 6A2.
Poor knock sensor performance “DTC P0325 DIAG. FLOW TABLE”
in this section.
Overheating
Inoperative thermostat Thermostat in Section 6B.
Poor water pump performance Water pump in Section 6B.
Clogged or leaky radiator Radiator in Section 6B.
Improper engine oil grade Engine oil and oil filter change in
Section 0B.
Clogged oil filter or oil strainer Oil pressure check in Section 6A2.
Poor oil pump performance Oil pressure check in Section 6A2.
Dragging brakes Diagnosis in Section 5.
Slipping clutch Diagnosis in Section 7C1.
Blown cylinder head gasket Cylinder head inspection in Section
6A2. Condition Possible Cause Correction

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.

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.

6-1-76 ENGINE GENERAL INFORMATION AND DIAGNOSIS (H27 ENGINE)
DTC P0171/P0172 Fuel System Too Lean/Rich (Bank 1)
DTC DETECTING CONDITION AND POSSIBLE CAUSE
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 warm up
engine completely.
3) Increase vehicle speed to 50 – 60 km/h (30 – 40 mph).
4) Keep driving above vehicle speed for 3 min. or more.
5) Stop vehicle and check pending DTC by using scan tool.DTC DETECTING CONDITION TROUBLE AREA
When running after engine warmed (2 driving cycle
detection logic).
• Short term fuel trim exceeding 15 % or long term fuel
trim exceeding 20 % and total trim exceeding 43 % is
detected.
– Fuel system too lean
• Short term fuel trim less than – 11 % or long term fuel
trim less than – 11 % and total trim less than – 30 % is
detected.
– Fuel trim too rich• Vacuum leaks (air inhaling)
• Exhaust gas leakage
• Fuel pressure out of specification
• Heated oxygen sensor malfunction
• EGR system malfunction
• MAF sensor poor performance
• ECT sensor poor performance
• Fuel level sensor.
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 persons, 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. at start : – 8 – 60°C (18 – 140°F)
Engine coolant temp. at start : – 8 – 95°C (18 – 203°F)
Altitude (barometric pressure) : 2400 m, 8000 ft or less (560 mmHg (75 kPa) or more)
Intake air temp. : – 8°C (18°F) or higher
Engine coolant temp. : 110°C (230°F) or lower