engine overheat SUZUKI GRAND VITARA 2001 2.G Owners Manual

1B-12 AIR CONDITIONING (OPTIONAL)
Performance diagnosis table
HIGH PRESSURE GAUGE
LOW PRESSURE GAUGE
THERMOMETER AT CENTER DUCT
Condition Possible Cause Correction
Pressure high
(“A” area of high side
graph)Refrigerant overcharged Recharge.
Expansion valve frozen or clogged Check expansion valve.
Clogged refrigerant passage of high side Clean or replace.
Condenser cooling fan malfunction (Insufficient cooling
of condenser)Check condenser cooling fan.
Dirty or bent condenser fins (Insufficient cooling of con-
denser)Clean or repair.
Compressor malfunction (Insufficient oil etc.) Check compressor.
Engine overheat Check engine cooling system.
Pressure low
(“B” area of high side
graph)Insufficient refrigerant (Insufficient charge or leakage) Check for leakage, repair if necessary
and recharge.
Expansion valve malfunction (valve opens too wide) Check expansion valve.
Compressor malfunction (Insufficient compression) Check compressor.
Condition Possible Cause Correction
Pressure high
(“C” area of low side
graph)Expansion valve malfunction (valve opens too wide) Check expansion valve.
Compressor malfunction (Insufficient compression) Check compressor.
Pressure low
(“D” area of low side
graph)Insufficient refrigerant (Insufficient charge or leakage) Check for leakage, repair if necessary
and recharge.
Expansion valve malfunction (valve opens too narrow) Check expansion valve.
Clogged refrigerant passage (crashed pipe) Repair or replace.
Condition Possible Cause Correction
Outlet air temperature at
center duct is high
(Crossing point is in area
“E”)Insufficient or excessive charge of refrigerant Check refrigerant pressure.
Dirty or bent A/C evaporator fins Clean or repair.
Air leakage from cooling (heater) unit or air duct Repair or replace.
Malfunctioning, switch over function of damper in cool-
ing (heater) unitRepair or replace.
Compressor malfunction Check compressor.
Outlet air temperature at
center duct is low
(Crossing point is in area
“F”)Insufficient air volume from center duct (Heater blower
malfunction)Check blower motor and fan.
Compressor malfunction Check compressor.
NOTE:
If ambient temperature is within 30 - 35 °C (85 - 95 °F), it is possible to do using “DETAIL DIAGNOSIS
TABLE” in this section for detail diagnosis.

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

6-1-80 ENGINE GENERAL INFORMATION AND DIAGNOSIS (H27 ENGINE)
DTC P0300/P0301/P0302/P0303/P0304/P0305/P0306 Random Misfire/Cylinder
1 Misfire/Cylinder 2 Misfire/Cylinder 3 Misfire/Cylinder 4 Misfire Detected/Cyl-
inder 5 Misfire Detected/Cylinder 6 Misfire Detected
SYSTEM DESCRIPTION
ECM (PCM) measures the angle speed of the crankshaft based on the pulse signal from the CKP sensor and
CMP sensor for each cylinder. If it detects a large change in the angle speed of the crankshaft, it concludes
occurrence of a misfire. When the number of misfire is counted by the ECM (PCM) beyond the DTC detecting
condition, it determines the cylinder where the misfire occurred and outputs it as DTC.
DTC DETECTING CONDITION AND TROUBLE AREA
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 start
engine.
3) Increase vehicle speed to speed recorded as freeze frame data (V) ± 5 km/h when detecting misfire.
4) Keep driving above vehicle speed for 5 min.
5) Stop vehicle and check DTC (or pending DTC) by using scan tool.DTC DETECTING CONDITION TROUBLE AREA
DTC P0300 :
• Misfire which causes catalyst to overheat during 200 engine
revolutions is detected at 2 or more cylinders. (MIL flashes as
long as this misfire occurs continuously.)
• Misfire which affects exhaust emission adversely during 1000
engine revolutions is detected at 2 or more cylinders (2 driving
cycle detection logic)• Ignition system
• Fuel injector and its circuit
• Fuel line pressure
• Engine compression
• Abnormal air drawn in
• EGR system
• Fuel level sensor
• Valve lash adjuster
• Valve timing DTC P0301, P0302, P0303, P0304, P0305, P0306 :
• Misfire which causes catalyst to overheat during 200 engine
revolutions is detected at 1 cylinder. (MIL flashes as long as
this misfire occurs continuously.)
• Misfire which affects exhaust emission adversely during 1000
engine revolutions is detected at 1 cylinder
(2 driving cycle detection logic)
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. : – 8 – 70°C (18 – 158°F)
Engine coolant temp. : – 8°C (18°F) or higher
Altitude (barometric pressure) : 2400 m, 8000 ft or less (560 mmHg (75 kPa) or more)