ECT sensor SUZUKI GRAND VITARA 2001 2.G Repair Manual

ENGINE GENERAL INFORMATION AND DIAGNOSIS (H27 ENGINE) 6-1-77
TROUBLESHOOTING
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 Is there DTC (s) other than “DTC P0171/
P0172”?Go to applicable DTC
FLOW TABLE.Go to Step 3.
3 Check intake system and exhaust system for
leakage.
Are intake system and exhaust system in good
condition?Go to Step 4. Repair or replace.
4 Check fuel pressure referring to “TABLE B-3” in
this section.
Is check result satisfactory?Go to Step 5. Repair or replace.
5 Check fuel injectors referring to “FUEL INJEC-
TOR INSPECTION” in Section 6E2.
Is check result satisfactory?Go to Step 6. Faulty injector (s).
6 Check fuel level sensor referring to “FUEL
LEVEL SENSOR” in Section 6E2.
Is check result satisfactory?Go to Step 7. Faulty fuel level sensor or
its circuit.
7 Check MAF sensor for performance referring to
“MASS AIR FLOW SENSOR” in Section 6E2.
Is check result satisfactory?Go to Step 8. Faulty MAF sensor or its
circuit.
8 Check ECT sensor referring to Section 6E2.
Is check result satisfactory?Go to Step 9. Faulty ECT sensor.
9 Check HO2S-1 referring to “DTC P0130 DIAG.
FLOW TABLE”.
Is check result satisfactory?Substitute a known-good
ECM (PCM) and recheck.Faulty HO2S-1.

6-1-78 ENGINE GENERAL INFORMATION AND DIAGNOSIS (H27 ENGINE)
DTC P0174/P0175 Fuel System Too Lean/Rich (Bank 2)
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

ENGINE GENERAL INFORMATION AND DIAGNOSIS (H27 ENGINE) 6-1-79
TROUBLESHOOTING
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 Is there DTC (s) other than “DTC P0174/
P0175”?Go to applicable DTC
FLOW TABLE.Go to Step 3.
3 Check intake system and exhaust system for
leakage.
Are intake system and exhaust system in good
condition?Go to Step 4. Repair or replace.
4 Check fuel pressure referring to “TABLE B-3” in
this section.
Is check result satisfactory?Go to Step 5. Repair or replace.
5 Check fuel injectors referring to “FUEL INJEC-
TOR INSPECTION” in Section 6E2.
Is check result satisfactory?Go to Step 6. Faulty injector (s).
6 Check fuel level sensor referring to “FUEL
LEVEL SENSOR” in Section 6E2.
Is check result satisfactory?Go to Step 7. Faulty fuel level sensor or
its circuit.
7 Check MAF sensor for performance referring to
“MASS AIR FLOW SENSOR” in Section 6E2.
Is check result satisfactory?Go to Step 8. Faulty MAF sensor or its
circuit.
8 Check ECT sensor referring to Section 6E2.
Is check result satisfactory?Go to Step 9. Faulty ECT sensor.
9 Check HO2S-1 referring to “DTC P0150 DIAG.
FLOW TABLE”.
Is check result satisfactory?Substitute a known-good
ECM (PCM) and recheck.Faulty HO2S-1.

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)

ENGINE GENERAL INFORMATION AND DIAGNOSIS (H27 ENGINE) 6-1-81
TROUBLESHOOTING
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 Ignition system inspection :
1) Check spark plug and ignition spark of cylin-
der where misfire occurs, referring to “IGNI-
TION SYSTEM” section.
Is it in good condition?Go to Step 3. Faulty ignition coil, wire
harness, or other system
parts.
3 Fuel injector circuit inspection :
1) Using sound scope, check each injector
operating sound at engine cranking or
idling.
Do all injectors make operating sound?Go to Step 4. Check coupler connec-
tion and wire harness of
injector not making oper-
ating sound and injector
itself.
If OK, substitute a known-
good ECM (PCM) and
recheck.
4 Fuel pressure inspection :
1) Check fuel pressure referring to “TABLE B-
3” in this section.
Is check result satisfactory?Go to Step 5. Repair or replace.
5 Fuel injector inspection :
1) Check fuel injector(s) referring to Section
6E2.
Is check result satisfactory?Go to Step 6. Replace.
6 Ignition timing inspection :
1) Check ignition timing referring to Section
6F2.
Is check result satisfactory?Go to Step 7. Adjust or check system
related parts.
7 EGR system inspection :
1) Check EGR system referring to Section
6E2.
Is check result satisfactory?Go to Step 8. Repair or replace.
8 Fuel level sensor inspection :
1) Check fuel level sensor referring to Section
6E2.
Is check result satisfactory?Go to Step 9. Repair or replace.
9 Check engine mechanical parts or system
which can cause engine rough idle or poor per-
formance.
• Engine compression (See Section 6A2).
• Valve lash or lash adjuster (See Section
6A2).
• Valve timing (Timing belt or chain installa-
tion. See Section 6A2).
Are they in good condition?Check wire harness and
connection of ECM (PCM)
ground, ignition system
and fuel injector for inter-
mittent open and short.Repair or replace.

6-1-82 ENGINE GENERAL INFORMATION AND DIAGNOSIS (H27 ENGINE)
DTC P0325 (DTC No.43) Knock Sensor Circuit Malfunction
CIRCUIT DESCRIPTION
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.
3) Start engine and run it for 10 sec.
4) Check DTC by using scan tool.
1. Knock sensor
2. ECM (PCM)
DTC DETECTING CONDITION TROUBLE AREA
DTC will set when one of the following condition is
detected.
• KNOCK sensor voltage is 0.90 V or less, or
• KNOCK sensor voltage is 3.98 V or more• “WHT” circuit open or shorted to ground
• KNOCK sensor malfunction
• ECM malfunction

ENGINE GENERAL INFORMATION AND DIAGNOSIS (H27 ENGINE) 6-1-83
TROUBLESHOOTING
Fig. for Steps 2 and 3Step 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 Knock sensor and its circuit check :
1) With engine running, check voltage from
“C51-3-3” terminal of ECM connector to
body ground. See Fig.
Is voltage about 0.90 – 3.98 V?Knock sensor and its cir-
cuit are in good condition.
Intermittent trouble or
faulty ECM.
Recheck, referring to
“INTERMITTENT TROU-
BLE” in Section 0A.Go to Step 3.
3 Knock sensor power source circuit check :
1) Stop engine.
2) With ignition switch at OFF position, discon-
nect knock sensor connector.
3) With ignition switch at ON position, check
voltage from “WHT” to body ground terminal
of knock sensor connector. See Fig.
Is it 4 – 5 V?Substitute a known-good
knock sensor and
recheck.“WHT” wire open, shorted
to ground circuit or poor
“C51-3-3” connection.
If wire and connection are
OK, substitute a known-
good substitute a known-
good ECM and recheck.
1. Knock sensor
2. Knock sensor connector

6-1-84 ENGINE GENERAL INFORMATION AND DIAGNOSIS (H27 ENGINE)
DTC P0335 Crankshaft Position Sensor Circuit Malfunction
WIRING DIAGRAM
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 run
engine at idle speed for 10 sec.
3) Check DTC by using scan tool.
1. CKP sensor
2. ECM (PCM)
DTC DETECTING CONDITION TROUBLE AREA
CKP sensor signal is not input while 100 pulses of
CMP sensor signal are input after engine start.CKP sensor circuit
CKP sensor
ECM (PCM)
NOTE:
Check to make sure that following condition is satisfied when using this “DTC CONFIRMATION PRO-
CEDURE”.
Intake air temp. : – 8°C (18°F) or higher
Engine coolant temp. : – 8 – 110°C (18 – 230°F)
Altitude (barometric pressure) : 2400 m, 8000 ft or less (560 mmHg (75 kPa) or more)

ENGINE GENERAL INFORMATION AND DIAGNOSIS (H27 ENGINE) 6-1-85
TROUBLESHOOTING
[A] Fig. for Step 3 / [B] Fig. for Step 4Step Action Yes No
1 Was “ENGINE DIAG. FLOW TABLE” performed? Go to Step 2. Go to “ENGINE DIAG.
FLOW TABLE” in this
section.
2 CKP sensor and its circuit resistance check :
1) With ignition switch OFF, disconnect ECM
(PCM) coupler (C51-2).
2) Check for proper connection to ECM (PCM) at
C51-2-19 and C51-2-20 terminals.
3) If OK, check resistance of followings.
CKP sensor resistance between C51-2-19 and
C51-2-20 terminals :
484 – 656
Ω
ΩΩ Ω at 20°C (68°F)
CKP sensor resistance between each terminal
and ground :
1 M
Ω
ΩΩ Ω or more
Is check result satisfactory?Go to Step 4. Go to Step 3.
3 CKP sensor resistance check :
1) With ignition switch OFF, disconnect CKP sen-
sor coupler.
2) Check resistance between terminals of CKP
sensor coupler. (See Fig.)
Were measured resistance values as specified in
Step 2?Faulty “WHT/BLU” wire
or “ORN/BLU” wire.Faulty CKP sensor.
4 CKP sensor visual inspection :
Check visually CKP sensor and signal rotor for the
followings. (See Fig.)
• Damage
• No foreign material attached
• Correct installation
Are they in good condition?Intermittent trouble or
faulty ECM (PCM).
Recheck for intermit-
tent referring to
“INTERMITTENT AND
POOR CONNEC-
TION” in Section 0A.Replace or reinstall.
1. Sensor plate

6-1-86 ENGINE GENERAL INFORMATION AND DIAGNOSIS (H27 ENGINE)
DTC P0340 (DTC No.42) Camshaft Position Sensor Circuit Malfunction
WIRING DIAGRAM
SYSTEM DESCRIPTION
CMP sensor detects REF signal and POS signal.
• REF signal : 4 pulses/1 revolution of camshaft. There are 2 different kinds of wavelength. Based on REF sig-
nal, ECM (PCM) judges which cylinder is at TDC.
• POS signal : 6 pulse/1 revolution of camshaft. Each of POS signals has equivalent wavelength. Based on
POS signal, ECM (PCM) judges the wavelength of REF signals, engine speed and piston position.
REFERENCE
Connect oscilloscope between terminals C51-1-13 (POS) or C51-1-12 (REF) and C51-3-26 (ground) of ECM
(PCM) connector connected to ECM (PCM) and check CMP sensor signal.
1. CMP sensor
2. To main relay
3. ECM (PCM)