2001 SUZUKI GRAND VITARA ECT sensor

ENGINE GENERAL INFORMATION AND DIAGNOSIS (H27 ENGINE) 6-1-27
Scan tool data definitions
COOLANT TEMP (Engine Coolant Temp., °C/°F)
It is detected by engine coolant temp. sensor.
INTAKE AIR TEMP (°C/°F)
It is detected by intake air temp. sensor.
DESIRE IDLE (Desired Idle Speed RPM)
The desired idle speed is an ECM (PCM) internal parameter which indicates the ECM (PCM) requested idle. If
the engine is not running, the number is not valid.
CLOSED THROT POS (Closed Throttle Position ON/OFF)
This parameter will read ON when the throttle valve is fully closed. Or OFF when the throttle is not fully closed.
IAC FLOW DUTY (%)
This parameter indicates IAC valve opening rate which controls bypass air flow.
ENGINE SPEED (RPM)
It is computed by reference pulses from the Camshaft Position Sensor.
SHORT FT B1 (Short Term Fuel Trim Bank 1, %) / SHORT FT B2 (Short Term Fuel Trim Bank 2, %)
Short term fuel trim value represents short term corrections to the air/fuel mixture computation. A value of 0 indi-
cates no correction, a value greater than 0 means an enrichment correction, and a value less than 0 implies an
enleanment correction.
LONG FT B1 (Long Term Fuel Trim Bank 1, %) / LONG FT B2 (Long Term Fuel Trim Bank 2, %)
Long term fuel trim value represents long term corrections to the air/fuel mixture computation. A value of 0 indi-
cates no correction, a value greater than 0 means an enrichment correction, and a value less than 0 implies an
enleanment correction.
IGNITION ADVANCE (Ignition Timing Advance For No.1 Cylinder, °)
Ignition timing of No.1 cylinder is commanded by ECM (PCM). The actual ignition timing should be checked by
using the timing light.
BATTERY VOLTAGE (V)
This parameter indicates battery positive voltage inputted from main relay to ECM (PCM).
MAF (Mass Air Flow Rate, g/s, lb/min)
It represents total mass of air entering intake manifold which is measured by mass air flow sensor.
INJ PULSE WIDTH B1 (Fuel Injection Pulse Width Bank 1, msec) / INJ PULSE WIDTH B2 (Fuel Injec-
tion Pulse Width Bank 2, msec)
This parameter indicates time of the injector drive (valve opening) pulse which is output from ECM (PCM).
THROTTLE POS (Absolute Throttle Position, %)
When throttle position sensor is fully closed position, throttle opening is indicated as 0 % and 100 % for full open
position.

6-1-28 ENGINE GENERAL INFORMATION AND DIAGNOSIS (H27 ENGINE)
TP SENSOR VOLT (TP Sensor Output Voltage, V)
Throttle Position Sensor reading provides throttle valve opening information in the from of voltage.
O2S B1 S1 (HO2S Bank 1 Sensor 1 Output Voltage, V) / O2S B2 S1 (HO2S Bank 2 Sensor 1 Output
Voltage, V)
It indicates output voltage of HO2S SENSOR 1 installed on exhaust manifold (pre-catalyst).
O2S B1 S2 (HO2S Bank 1 Sensor 2 Output Voltage, V) / O2S B2 S2 (HO2S Bank 2 Sensor 2 Output
Voltage, V)
If indicates output voltage of HO2S SENSOR 2 installed on exhaust pipe (post-catalyst). It is used to detect cat-
alyst deterioration.
FUEL SYSTEM B1 (Fuel System Bank 1 Status) / Fuel System B2 (Fuel System Bank 2 Status)
Air/fuel ratio feedback loop status displayed as one of the followings.
OPEN : Open loop-has not yet satisfied conditions to go closed loop.
CLOSED : Closed loop-using oxygen sensor(s) as feedback for fuel control.
OPEN-DRIVE COND : Open loop due to driving conditions (Power enrichment, etc.).
OPEN SYS FAULT : Open loop due to detected system fault.
CLOSED-ONE O2S : Closed loop, but fault with at least one oxygen sensor may be using single oxygen sensor
for fuel control.
CALC LOAD (Calculated Load Value, %)
Engine load displayed as a percentage of maximum possible load. Value is calculated mathematically using the
formula : actual (current) intake air volume ÷ maximum possible intake air volume x 100%.
TOTAL FUEL TRIM (%)
The value of total fuel trim is obtained by putting values of short term fuel trim and long term fuel trim together.
This value indicates how much correction is necessary to keep the air/fuel mixture stoichiometrical.
CANIST PRG DUTY (EVAP Canister Purge Flow Duty, %)
This parameter indicates valve ON (valve open) time rate within a certain set cycle of EVAP canister purge valve
which controls the amount of EVAP purge.
VEHICLE SPEED (km/h, MPH)
It is computed based on pulse signals from vehicle speed sensor on transfer or transmission.
FUEL CUT (ON/OFF)
ON : Fuel being cut (output signal to injector is stopped).
OFF : Fuel not being cut.
MAP (Manifold Absolute Pressure, mmHg, kPa)
This parameter indicates the pressure in the intake manifold absolute pressure.
A/C CONDENSER FAN (ON/OFF)
This parameter indicates the state of the A/C Condenser Fan control signal.
BLOWER FAN (ON/OFF)
This parameter indicates the state of the blower fan motor switch.

ENGINE GENERAL INFORMATION AND DIAGNOSIS (H27 ENGINE) 6-1-29
EGR VALVE (%)
This parameter indicates opening rate of EGR valve which controls the amount of EGR flow.
A/C SWITCH (ON/OFF)
ON : Command for operation being output from A/C amplifier to compressor.
OFF : Command for operation not being output.
PSP SWITCH (ON/OFF)
ON : PSP switch detects P/S operation. (high P/S pressure)
OFF : PSP switch not detects P/S operation.
PNP SIGNAL (Transmission Range Switch, P/N or D range)
Whether the transmission range switch (P/N position switch) at P or N range or at R, D, 2 or L range is displayed.
If at P or N range, “P/N range” is displayed and if at R, D, 2 or L range, “D range” is displayed.
FUEL TANK LEVEL (%)
This parameter indicates approximate fuel level in the fuel tank. As the detectable range of the fuel level sensor
is set as 0 to 100 %, however, with some models whose fuel tank capacity is smaller, the indicated fuel level may
be only 70 % even when the fuel tank is full.
ELECTRIC LOAD (ON/OFF)
ON : Small light switch ON or rear window defogger switch ON.
OFF : Small light switch OFF and rear window defogger switch OFF.
VSS (4-A/T) (km/h, MPH)
It is computed by using pulse signals from vehicle speed sensor on 4-speed automatic transmission.
THROT POS LEVEL (Throttle Position Level For 4-A/T, “0”, “1”, “2”, “3”, “4”,“5”,“6” or “7”)
This parameter indicates which level (zone) the throttle valve opening is in.
The throttle opening is divided into 8 levels (zones) from “0” (about idle position) to “7” (about full open) and sig-
nals are assigned to each opening level (zone). PCM controls the automatic gear change of the automatic trans-
mission by using these signals according to the signal from the TP sensor.
GEAR POSITION (1ST, 2ND, 3RD or 4TH)
The gear position is determined on the basis of the command state signals generated from PCM to shift sole-
noids A and B (#1 and #2) and displayed as shown in the table below.
SHIFT SOL #1 CON/MON (Shift Solenoid #1, A Command/monitor, ON/OFF)
CON-ON : ON command being output to shift solenoid #1, A.
CON-OFF : ON command not being output.
MON-ON : Electricity being passed to shift solenoid #1, A.
MON-OFF : Electricity not being passed.SHIFT SOLENOID-A SHIFT SOLENOID-B
DISPLAY1ST ON OFF
2ND ON ON
3RD OFF ON
4TH OFF 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

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

6-1-34 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

6-1-38 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