ECT sensor SUZUKI JIMNY 2005 3.G Service Owners Manual

Downloaded from www.Manualslib.com manuals search engine 6-68 ENGINE GENERAL INFORMATION AND DIAGNOSIS
DTC P0171 Fuel System Too Lean
DTC P0172 Fuel System Too Rich
CIRCUIT DESCRIPTION
[a] : Signal to decrease amount of fuel injection [d] : A/F mixture becomes richer
(Oxygen concentration decreases)1. Injector
[b] : Signal to increase amount of fuel injection [e] : High voltage 2. Heated oxygen sensor-1 (HO2S-1)
[c] : A/F mixture becomes leaner
(Oxygen concentration increases)[f] : Low voltage
DTC DETECTING CONDITION POSSIBLE CAUSE
When following condition occurs while engine running
under closed loop condition.
–Air / fuel ratio too lean
(Total fuel trim (short and long terms added) is more
than 30%)
or
–Air / fuel ratio too rich
(Total fuel trim is less than –30%)
✱
✱✱ ✱2 driving cycle detection logic, continuous monitoring.Vacuum leaks (air drawn in).
Exhaust gas leakage.
Heated oxygen sensor-1 circuit malfunction.
Fuel pressure out of specification.
Fuel injector malfunction (clogged or leakage).
MAP sensor poor performance.
ECT sensor poor performance.
IAT sensor poor performance.
TP sensor poor performance.
EVAP control system malfunction.
PCV valve malfunction.

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5 Check Fuel Injectors and Circuit.
1) Using sound scope (4) or such, check operating
sound of each injector (5) when engine is run-
ning. Cycle of operating sound should vary
according to engine speed. See Fig. 3.
If no sound or an unusual sound is heard, check
injector circuit (wire or coupler) or injector.
2) Turn ignition switch OFF and disconnect a fuel
injector connector.
3) Check for proper connection to fuel injector at
each terminal.
4) If OK, then check injector resistance.
See Fig. 4.
Injector resistance
11.3 – 13.8 ohm at 20 °C (68 °F)
5) Carry out steps 1) and 3) on each injector.
6) Check each injector for injected fuel volume
referring to Section 6E. See Fig. 5.
Injected fuel volume
43 – 47 cc/15 sec (1.45/1.51 – 1.58/1.65 US/
Imp.oz/15 sec)
7) Check each injector for fuel leakage after injec-
tor closed.
Fuel leakage
Less than 1 drop / min. (1)
Is check result in step 1) and 3) to 7) satisfactory?Go to Step 6. Check injector circuit or
replace fuel injector(s).
6 Check EVAP Canister Purge Valve.
1) Disconnect purge hose (2) from EVAP canister.
2) Place finger against the end of disconnected
hose.
3) Check that vacuum is not felt there when
engine is cool and running at idle. See Fig. 6.
Is vacuum felt?Check EVAP control
system (See Section
6E).Go to Step 7.
7 Check intake manifold absolute pressure sensor for
performance (See step 4) of DTC P0105 (No.11)
Diag. Flow Table).
Is it in good condition?Go to Step 8. Repair or replace.
8 Check engine coolant temp. sensor for perfor-
mance (See Section 6E).
Is it in good condition?Go to Step 9. Replace engine coolant
temp. sensor.
9 Check intake air temp. sensor for performance
(See Section 6E).
Is it in good condition?Go to Step 10. Replace intake air temp.
sensor.
10 Check throttle position sensor for performance
(See step 5) of DTC P0121 Diag. Flow Table).
Is it in good condition?Go to Step 11. Replace throttle position
sensor.
11 Check PCV valve for valve clogging
(See Section 6E).
Is it good condition?Substitute a known-
good ECM and recheck.Replace PCV valve. Step Action Yes No

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DTC P0300 Random Misfire Detected (Misfire Detected at 2 or More Cylinders)
DTC P0301 Cylinder 1 Misfire Detected
DTC P0302 Cylinder 2 Misfire Detected
DTC P0303 Cylinder 3 Misfire Detected
DTC P0304 Cylinder 4 Misfire Detected
CIRCUIT DESCRIPTION
ECM monitors crankshaft revolution speed and engine speed via the crankshaft position sensor and cylinder No.
via the camshaft position sensor. Then it calculates the change in the crankshaft revolution speed and from how
many times such change occurred in every 200 or 1000 engine revolutions, it detects occurrence of misfire.
When ECM detects a misfire (misfire rate per 200 revolutions) which can cause overheat and damage to the
three way catalytic converter, it makes the malfunction indicator lamp (MIL) flash as long as misfire occurs at
that rate.
After that, however, when the misfire rate drops, MIL remains ON until it has been judged as normal 3 times
under the same driving conditions.
Also, when ECM detects a misfire (misfire rate per 1000 revolutions) which will not cause damage to three way
catalytic converter but can cause exhaust emission to be deteriorated, it makes MIL light according to the 2 driv-
ing cycle detection logic.
1. Ignition coil assembly (for No.1 and No.4 cylinder)
2. Ignition coil assembly (for No.2 and No.3 cylinder)
3. Fuel injector
4. CKP sensor
5. CMP sensor

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DTC CONFIRMATION PROCEDURE
1) Turn ignition switch OFF.
2) Clear DTC with ignition switch ON.
3) Check vehicle and environmental condition for :
–Altitude (barometric pressure) : 2400 m, 8000 ft or less (560 mmHg, 75 kPa or more)
–Ambient temp. : –10 °C, 14 °F or higher
–Intake air temp. : 70 °C, 158 °F or lower
–Engine coolant temp. : – 10 – 110 °C, 14 – 230 °F
4) Start engine and keep it at idle for 2 min. or more.
5) Check DTC in “DTC” mode and pending DTC in “ON BOARD TEST” or “PENDING DTC” mode.
6) If DTC is not detected at idle, consult usual driving based on information obtained in “Customer complaint
analysis” and “Freeze frame data check”.
INSPECTION
DTC DETECTING CONDITION POSSIBLE CAUSE
Engine under other than high revolution condition
Not on rough road
Engine speed changing rate (below specified value)
Manifold absolute pressure changing rate (below
specified value)
Throttle opening changing rate (below specified
value)
Misfire rate per 200 or 1000 engine revolutions (how
much and how often crankshaft revolution speed
changes) is higher than specified valueEngine overheating
Vacuum leaks (air inhaling) from air intake system
Ignition system malfunction (spark plug(s), high-
tension cord(s), ignition coil assembly)
Fuel pressure out of specification
Fuel injector malfunction (clogged or leakage)
Engine compression out of specification
Valve lash (clearance) out of specification
Manifold absolute pressure sensor malfunction
Engine coolant temp. sensor malfunction
PCV valve malfunction
EVAP control system malfunction
EGR system malfunction
NOTE:
Among different types of random misfire, if misfire occurs at cylinders 1 and 4 or cylinders 3 and 2
simultaneously, it may not possible to reconfirm DTC by using the following DTC confirmation proce-
dure. When diagnosing the trouble of DTC P0300 (Random misfire detected) of the engine which is
apparently misfiring, even if DTC P0300 cannot be reconfirmed by using the following DTC confirma-
tion procedure, proceed to the following Diag. Flow Table.
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.
Step Action Yes No
1Was “Engine Diag. Flow Table” performed? Go to Step 2. Go to “Engine
Diag. Flow Table”.
2 Is there DTC other than Fuel system (DTC P0171/
P0172) and misfire (DTC P0300 – P0304)?Go to applicable DTC
Diag. Flow Table.Go to Step 3.

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[A] Fig. 1 for Step 3 / [B] Fig. 2 for Step 3 / [C] Fig. 3 for Step 4 / [D] Fig. 4 for Step 5 / [E] Fig. 5 for Step 47 Check EVAP Canister Purge Valve for Closing.
1) Disconnect purge hose (1) from EVAP canister.
2) Place finger against the end of disconnected hose.
3) Check that vacuum is not felt there, when engine is
cool and running at idle. See Fig. 7.
Is vacuum felt?Check EVAP control
system
(See Section 6E).Go to Step 8.
8 Check manifold absolute pressure sensor for perfor-
mance (See step 4) DTC P0105 Diag. Flow Table).
Is it in good condition?Go to Step 9. Repair or replace.
9 Check engine coolant temp. sensor for performance
(See Section 6E).
Is it in good condition?Go to Step 10. Replace engine
coolant temp. sen-
sor.
10 Check parts or system which can cause engine rough
idle or poor performance.
Engine compression (See Section 6A1).
Valve lash (See Section 6A1).
Valve timing (Timing belt installation. See Section
6A1).
Are they in good condition?Check wire harness
and connection of
ECM ground, ignition
system and fuel injec-
tor for intermittent
open and short.Repair or replace. Step Action Yes No
CAUTION:
For iridium spark plugs, do not adjust air gap or clean.
3. Fuel delivery pipe
4. Fuel feed hose
3. Fuel pressure gauge & 3 way joint

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DTC P0325 (DTC No.17) Knock Sensor Circuit Malfunction
CIRCUIT DESCRIPTION
DTC CONFIRMATION PROCEDURE
1) Clear DTC, start engine and keep it at idle for 1 min.
2) Select “DTC” mode on scan tool and check DTC.
INSPECTION
DTC DETECTING CONDITION POSSIBLE CAUSE
Knock sensor voltage is 3.91 V or more
Knock sensor voltage is 1.23 V or less“W” circuit open or shorted to ground
Knock sensor malfunction
ECM malfunction
Step Action Yes No
1Was “Engine Diag. Flow Table” performed? Go to Step 2. Go to “Engine Diag. Flow
Table”.
2 1) With engine running, check voltage from
“E19-25” terminal of ECM connector to
body ground. See Fig. 1.
2) Is voltage about 1.25 – 3.75 V?Knock sensor and its cir-
cuit are in good condition.
Intermittent trouble or
faulty ECM.
Recheck, referring to
“Intermittent Trouble” in
Section 0A.Go to Step 3.
3 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 “W” to body ground terminal of
knock sensor connector. See Fig. 2.
Is it 4 – 5 V?Faulty knock sensor.
Substitute a known-good
knock sensor and
recheck.“W” wire open, shorted to
ground circuit or poor
“E19-25” connection.
If wire and connection are
OK, substitute a known-
good ECM and recheck.

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DTC P0335 (DTC No.23) Crankshaft Position (CKP) Sensor Circuit Malfunction
CIRCUIT DESCRIPTION
REFERENCE
Connect oscilloscope between terminals E19-23 of ECM connector connected to ECM and body ground and
check CKP sensor signal.
DTC CONFIRMATION PROCEDURE
1) Clear DTC and crank engine for 2 sec.
2) Select “DTC” mode on scan tool and check DTC.
DTC DETECTING CONDITION POSSIBLE CAUSE
NO CKP sensor signal for 2 seconds at engine crank-
ing.CKP sensor circuit open or short.
Signal teeth damaged.
CKP sensor malfunction, foreign material being
attached or improper installation.
ECM malfunction.
1. 10° signal [A] : Oscilloscope Waveforms [C] : Waveforms at 2000 rpm
2. 30° signal [B] : Waveforms at idle speed

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INSPECTION
Step Action Yes No
1Was “Engine Diag. Flow Table” performed? Go to Step 2. Go to “Engine Diag.
Flow Table”.
2 Check CKP Sensor and connector for proper
installation.
Is CKP sensor installed properly and connector
connected securely?Go to Step 3. Correct.
3 Check Wire Harness and Connection.
1) Disconnect connector from CKP sensor.
2) Check for proper connection to CKP sensor at
each terminal.
3) If OK, turn ignition switch ON and check for
voltage at each terminal of sensor connector
disconnected. See Fig. 1.
Terminal “B+” : 10 – 14 V
Terminal “Vout” : 4 – 5 V
Terminal “GND” : 0 V
Is check result satisfactory?Go to Step 5. Go to Step 4.
4 Was terminal “Vout” voltage out of specification in
Step 3 check?“G/R” wire open, short or
poor connection.
If wire and connection are
OK, substitute a known-
good ECM and recheck.“Bl/B” or “B/R” wire
open, short or poor
connection.
5 Check Ground Circuit for Open.
1) Turn ignition switch OFF.
2) Check for continuity between “GND” terminal
of CKP sensor connector and engine ground.
Is continuity indicated?Go to Step 6.“B/R” wire open or
poor ground connec-
tion.
6 Check CKP Sensor for Operation.
1) Remove CKP sensor from sensor case.
2) Remove metal particles on end face of CKP
sensor, if any.
3) Connect each connector to ECM and CKP
sensor.
4) Turn ignition switch ON.
5) Check for voltage at terminal E19-23 of con-
nector connected to ECM by passing magnetic
substance (iron) (1) while keeping approxi-
mately 1 mm (0.03 in.) gap with respect to end
face of CKP sensor. See Fig. 2 and 3.
Does voltage vary from low (0 – 1 V) to high (4 – 5
V) or from high to low?Go to Step 7. Replace CKP sensor.
7 Check signal rotor for the following. See Fig. 4.
Damage
No foreign material attached
Is it in good condition?Intermittent trouble or
faulty ECM.
Check for intermittent
referring to “Intermittent
and Poor Connection” in
Section 0A.Clean rotor teeth or
replace CKP sensor.

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DTC P0340 (DTC No.15) Camshaft Position (CMP) Sensor Circuit Malfunction
CIRCUIT DESCRIPTION
REFERENCE
Connect oscilloscope between terminals E19-11 of ECM connector connected to ECM and body ground and
check CMP sensor signal.
DTC CONFIRMATION PROCEDURE
1) Clear DTC.
2) Start engine and keep it at idle for 1 min.
3) Select “DTC” mode on scan tool and check DTC.
DTC DETECTING CONDITION POSSIBLE CAUSE
The number of CMP sensor signal pulses is incor-
rect during 8 revolution of crankshaft.CMP sensor circuit open or short.
Signal rotor teeth damaged.
CMP sensor malfunction, foreign material being
attached or improper installation.
ECM malfunction.
CMP sensor phase lag.
1. No.1 cylinder 3. No.3 cylinder [A] : Oscilloscope Waveforms [C] : CKP sensor waveform
2. No.2 cylinder 4. No.4 cylinder [B] : Waveforms at specified idle speed [D] : CMP sensor waveform

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INSPECTION
Step Action Yes No
1Was “Engine Diag. Flow Table” performed? Go to Step 2. Go to “Engine Diag.
Flow Table”.
2 Check CMP Sensor and connector for proper installa-
tion.
Is CMP sensor installed properly and connector con-
nected securely?Go to Step 3. Correct.
3 Check Wire Harness and Connection.
1) Disconnect connector from CMP sensor.
2) Check for proper connection to CMP sensor at
each terminal.
3) If OK, turn ignition switch ON and check for volt-
age at each terminal of sensor connector discon-
nected. See Fig. 1.
Terminal “B+” : 10 – 14 V
Terminal “Vout” : 4 – 5 V
Terminal “GND” : 0 V
Is check result satisfactory?Go to Step 5. Go to Step 4.
4 Was terminal “Vout” voltage out of specification in
Step 3 check?“W” wire open, short or
poor connection.
If wire and connection
are OK, substitute a
known-good ECM and
recheck.“Bl/B” or “B/R” wire
open, short or poor
connection.
5 Check Ground Circuit for Open.
1) Turn ignition switch OFF.
2) Check for continuity between “GND” terminal of
CMP sensor connector and engine ground.
Is continuity indicated?Go to Step 6.“B/R” wire open or
poor ground connec-
tion.
6 Check CMP Sensor for Operation.
1) Remove CMP sensor from sensor case.
2) Remove metal particles on end face of CMP sen-
sor, if any.
3) Connect each connector to ECM and CMP sensor.
4) Turn ignition switch ON.
5) Check for voltage at terminal E19-11 of connector
connected to ECM by passing magnetic sub-
stance (iron) (1) while keeping approximately 1
mm (0.03 in.) gap with respect to end face of CMP
sensor. See Fig. 2 and 3.
Does voltage vary from low (0 – 1 V) to high (4 – 5 V)
or from high to low?Go to Step 7. Replace CMP sen-
sor.
7 Check signal rotor for the following.
See Fig. 4.
Damage
No foreign material attached
Is it in good condition?Intermittent trouble or
faulty ECM.
Check for intermittent
referring to “Intermittent
and Poor Connection” in
Section 0A.Clean rotor teeth or
replace CMP sensor.