2001 SUZUKI GRAND VITARA engine fuel

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

ENGINE GENERAL INFORMATION AND DIAGNOSIS (H27 ENGINE) 6-1-35
Engine noise
(Note : Before check-
ing the mechanical
noise, make sure the
followings : Ignition
timing is properly
adjusted, Specified
spark plug is used,
Specified fuel is used.)Faulty hydraulic valve lash adjuster Hydraulic valve lash adjuster in
Section 6A2.
Worn valve stem and guide Valves inspection in Section 6A2.
Weak or broken valve spring Valve springs inspection in Section
6A2.
Warped or bent valve Valves inspection in Section 6A2.
Loose camshaft housing bolts Camshafts in Section 6A2.
Worn piston, ring and cylinder bore Pistons and cylinders inspection in
Section 6A2.
Worn crankpin bearing Crankpin and connecting rod bear-
ing inspection in Section 6A2.
Worn crankpin Crankpin and connecting rod bear-
ing inspection in Section 6A2.
Loose connecting rod nuts Connecting rod installation in Sec-
tion 6A2.
Low oil pressure Refer to “LOW OIL PRESSURE” of
this table.
Worn crankshaft journal bearing Crankshaft and bearing inspection
in Section 6A2.
Worn crankshaft journal Crankshaft and bearing inspection
in Section 6A2.
Loose lower crankcase (bearing cap) bolts Crankshaft installation in Section
6A2.
Excessive crankshaft thrust play Crankshaft inspection in Section
6A2. Condition Possible Cause Correction

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) 6-1-41
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

6-1-58 ENGINE GENERAL INFORMATION AND DIAGNOSIS (H27 ENGINE)
DTC P0130 (DTC No.13) HO2S-1 (Bank 1) Circuit Malfunction or No Activity
Detected
WIRING DIAGRAM
DTC DETECTING CONDITION AND TROUBLE AREA
1. HO2S heater relay
2. ECM (PCM)
3. HO2S-1 (Bank-1)
NOTE:
For vehicle with monitor connector, DTC will set when following only (*) mark condition is detected.
DTC DETECTING CONDITION TROUBLE AREA
Any one of the following conditions are detected in idle state while running
under driving conditions described for “DTC CONFIRMATION PROCEDURE”.
• 4.5 V or more HO2S circuit voltage is detected, when 5 V power is con-
nected to HO2S circuit in ECM (PCM), or
• Max. output voltage of HO2S is 0.6 V or lower on average and its minimum
voltage on average is 0.3 V or lower.
• Min. output voltage of HO2S is over 3.0 V or
• Max. output voltage of HO2S is 0.74 V or higher on average and its min.
voltage on average is 0.33 V or higher.
• *Output voltage of HO2S-1 does not exceed 0.45 V for specified time.
(2 driving cycle detection logic)HO2S-1 or its circuit.
Fuel system
ECM (PCM)

6-1-60 ENGINE GENERAL INFORMATION AND DIAGNOSIS (H27 ENGINE)
Fig. for Step 2
DTC P0133 HO2S-1 (Bank 1) Circuit Slow Response
WIRING DIAGRAM/CIRCUIT DESCRIPTION
Refer to DTC P0130.
DTC DETECTING CONDITION AND TROUBLE AREA
DTC CONFIRMATION PROCEDURE
Refer to DTC P0130.
TROUBLESHOOTING
4 Short term fuel trim check :
1) Run engine at 2000 r/min. for 60 sec.
2) With engine idling, check short term fuel trim displayed
on scan tool.
Is it within – 20 to +20 %?Intermittent trouble
or faulty ECM
(PCM).
Check for intermit-
tent referring to
“INTERMITTENT
AND POOR CON-
NECTION” in Sec-
tion 0A.Go to DTC P0171/
P0172 Diag. Flow
Table. Step Action Yes No
1. Normal
2. NG
DTC DETECTING CONDITION TROUBLE AREA
Following conditions are detected in idle state while running under driving
conditions described for “DTC CONFIRMATION PROCEDURE”.
Hi/Lo cycle (TRANS TIME displayed on scan tool) of HO2S-1 output voltage
is longer than specification or response rates of Hi → Lo and Lo → Hi
(TRANS TIME displayed as R → L threshold V or L → R threshold V on scan
tool) are longer than specification.
(2 driving cycle detection logic)HO2S-1
ECM (PCM)
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 1) Replace HO2S-1 and recheck.
Is DTC P0133 detected?Substitute a known-good
ECM (PCM) and recheck.HO2S-1 malfunction.

ENGINE GENERAL INFORMATION AND DIAGNOSIS (H27 ENGINE) 6-1-63
DTC P0136 HO2S-2 (Bank 1) Circuit Malfunction
WIRING DIAGRAM
DTC DETECTING CONDITION AND TROUBLE AREA
DTC CONFIRMATION PROCEDURE
1. HO2S heater relay
2. ECM (PCM)
3. HO2S-2 (Bank-1)
DTC DETECTING CONDITION TROUBLE AREA
DTC will set when any one of following conditions is detected (2 driving
cycle detection logic).
• 4.5 V or more HO2S circuit voltage is detected when 5 V power is con-
nected to HO2S circuit in ECM (PCM).
• While running with A/F feed back, average output voltage during speci-
fied time is too high or too low.
or
• While running with A/F feed back, max output voltage during specified
time is lower than specified value or min. output voltage during speci-
fied time is higher than specified value.• HO2S-2 or its circuit
• Fuel system
•ECM (PCM)
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.