Downloaded from www.Manualslib.com manuals search engine 1A-104 Engine General Information and Diagnosis:
4Wire harness check
1) Disconnect connectors from ECM with ignition switch
turned OFF.
2) Check for proper connection of ECM connector at “C37- 43” terminal.
3) Measure voltage between “C37-43” terminal of ECM connector and engine ground with ignition switch turned
ON.
Is voltage 0 V? Substitute a known-
good ECM and recheck.
“RED” wire is shorted to
power circuit.
5 Wire harness check
1) Measure voltage between “WHT” wire terminal of
electric throttle body connector and engine ground with
ignition switch turned ON.
Is voltage 4 – 6 V? Go to Step 9.
Go to Step 6.
6 Wire harness check
1) Turn OFF ignition switch.
2) Remove ECM from its br acket with ECM connectors
connected.
3) Check for proper connection of ECM connector at “C37- 43” and “C37-40” terminals.
4) If OK, measure voltage between “C37-40” terminal of ECM connector and engine ground with ignition switch
turned ON.
Is voltage 4 – 6 V? “WHT” wire is open or
high resistance circuit.
Go to Step 7.
7 Wire harness check
1) Disconnect connectors from ECM with ignition switch
turned OFF.
2) Measure resistance between “WHT” and “RED” wire terminals of electric thrott le body assembly connector.
Is resistance infinity? Go to Step 8.
“WHT” wire is shorted to
“RED” wire.
8 Wire harness check
1) Turn ON ignition switch.
2) Measure voltage between “C37-40” terminal of ECM
connector and engine ground.
Is voltage 0 V? Substitute a known-
good ECM and recheck.
“WHT” wire is shorted to
power circuit.
9 Ground circuit check
1) Turn OFF ignition switch.
2) Measure resistance between “BLK” wire terminal of
electric throttle body connector and engine ground.
Is resistance below 5
Ω? Go to Step 11. Go to Step 10.
10 Ground circuit check
1) Remove ECM from its br acket with ECM connectors
connected.
2) Check for proper connection of ECM connector at “C37- 42” terminal.
3) Measure resistance between “C37-42” terminal of ECM connector and engine ground with ignition switch turned
OFF.
Is resistance below 5
Ω? “BLK” wire is open or
high resistance circuit.
Faulty ECM ground
circuit. If circuit is OK,
substitute a known-
good ECM and recheck.
Step Action Yes No
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DTC P0300 / P0301 / P0302 / P0303 / P0304: Random / Multiple Cylinder Misfire Detected / Cylinder 1
/ Cylinder 2 / Cylinder 3 / Cylinder 4 Misfire Detected
S7RS0B1104039
System Description
ECM measures the angle 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 ECM beyond the DTC de tecting condition, it determines the cylinder where the
misfire occurred and output it as DTC.
DTC Detecting Condition and Trouble Area
DTC Confirmation Procedure
WARNING!
• When performing a road test, select a place where there is no traffic or possibility of a traffic accident and be very careful during testing to avoid occurrence of an accident.
• Road test should be carried out by 2 persons, a driver and a tester, on a level road.
NOTE
Check to make sure that following conditions ar e satisfied when using this “DTC Confirmation
Procedure”.
• Intake air temperature at engine start: –10 °C (14 ° F) to 80 °C (176 °F)
• Intake air temperature: –10 °C (14 °F) to 70 °C (158 °F)
• Engine coolant temp.: –10 °C, 14 °F or higher
• Altitude (barometric pressure): 2400 m, 8000 ft or less (560 mmHg, 75 kPa or more)
1) With ignition switch turned OFF, connect scan tool.
2) Turn ON ignition switch and print Freeze Frame Data or write them down using scan tool.
3) Clear DTC using scan tool.
4) Drive vehicle under freeze frame data condition as noted for 1 min. or more.
5) Stop vehicle and check DTC and pending DTC. 11
Electric throttle body check
1) Check TP sensor referring to “Throttle Position Sensor
Performance Check” under “Electric Throttle Body
Assembly On-Vehicle Inspection in Section 1C”.
Is output voltage within specified value? Substitute a known-
good ECM and recheck.
Replace electric throttle
body.
Step Action Yes No
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 lo ng as this misfire occurs continuously.)
or
• Misfire, which affects exhaust emission adv ersely during 1000 engine revolution, is
detected at 2 or more cylinders. (2 driving cycle detection logic) • Ignition system
• Fuel injector and its circuit
• Fuel pressure
• EGR system
• Abnormal air drawn in
• Engine compression
• Valve lash adjuster
• Valve timing
• Fuel shortage
• Exhaust system
• Fuel of poor quality
DTC P0301, P0302, P0303, P0304:
• Misfire, which causes catalyst to overheat during 200 engine revolutions, is detected
at 1 cylinder. (MIL flashes as long as this misfire occurs continuously.)
or
• Misfire, which affects exhaust emission adv ersely during 1000 engine revolution, is
detected at 1 cylinder. (2 driving cycle detection logic)
Downloaded from www.Manualslib.com manuals search engine 1A-108 Engine General Information and Diagnosis:
DTC Troubleshooting
NOTE
• When measuring circuit voltage, resistance and/or pulse signal at ECM connector, connect the
special tool to ECM and/or the ECM connectors re ferring to “Inspection of ECM and Its Circuits”.
• Upon completion of inspection and repair work, perform “DTC Confirmation Procedure” and confirm that the trouble has been corrected.
Step Action YesNo
1 Was “Engine and Emission Control System Check”
performed? Go to Step 2.
Go to “Engine and
Emission Control
System Check”.
2 Knock sensor circuit check
1) Remove ECM from its br acket with ECM connectors
connected.
2) Measure voltage between “C37-56” terminal of ECM connector and vehicle body ground with engine running.
Is voltage within 1.23 – 3.91 V? Intermittent trouble.
Check for intermittent
referring to “Intermittent
and Poor Connection
Inspection in Section
00”. If OK, substitute a
known-good ECM and
recheck.Go to Step 3.
3 Knock sensor circuit for open check
1) Disconnect connector from knock sensor with ignition
switch turned OFF.
2) Turn ON ignition switch, measure voltage between “RED” wire of knock sensor connector and engine
ground.
Is voltage 4 – 6 V? Go to Step 6.
Go to Step 4.
4 Knock sensor circuit for open check
1) Turn ON ignition switch, measure voltage between “C37-
56” terminal of ECM connector and engine ground
Is voltage 4 – 6 V? “RED” wire is open
circuit.
Go to Step 5.
5 Knock sensor circuit for short check
1) Disconnect connectors from ECM with ignition switch
turned OFF.
2) Measure resistance between “C37-56” terminal of ECM connector and vehicle body ground.
Is resistance infinity? Go to Step 6.
“RED” wire is shorted to
ground circuit.
If wire is OK, substitute
a known-good ECM and
recheck.
6 Knock sensor circuit for short check
1) Disconnect connectors from ECM with ignition switch
turned OFF.
2) Turn ON ignition switch, measure voltage between “C37- 56” terminal of ECM connector and vehicle body ground.
Is voltage 0 V? Go to Step 7.
“RED” wire is shorted to
other circuit.
I2RH01110089-01
Downloaded from www.Manualslib.com manuals search engine Engine General Information and Diagnosis: 1A-115
DTC Troubleshooting
NOTE
• When measuring circuit voltage, resistance and/or pulse signal at ECM connector, connect the
special tool to ECM and/or the ECM connectors re ferring to “Inspection of ECM and Its Circuits”.
• Upon completion of inspection and repair work, perform “DTC Confirmation Procedure” and confirm that the trouble has been corrected.
Step Action YesNo
1 Was “Engine and Emission Control System Check”
performed? Go to Step 2.
Go to “Engine and
Emission Control
System Check”.
2 Ignition spark check
1) Check that each spark plug sparks referring to “Ignition
Spark Test in Section 1H”.
Is check result satisfactory? Intermittent trouble.
Check for intermittent
referring to “Intermittent
and Poor Connection
Inspection in Section
00”.Go to Step 3.
3 Ignition coil power, output and ground circuit check
1) Disconnect ignition coil connector of the cylinder found
as faulty in Step 2.
2) Check ignition coil circuit of the cylinder found as faulty in Step 2 for the following.
• Voltage between power circuit wire terminal of ignition coil connector and vehicle body ground is 10 – 14 V
with ignition switch turned ON.
• Voltage between output circuit wire terminal of ignition coil connector and vehicle body ground is 4 – 6 V with
ignition switch turned ON.
• Resistance between ground circuit wire terminal of ignition coil connector and vehicle body ground is less
than 2 Ω.
Are they in good condition? Go to Step 4.
Repair or replace
defective wire.
4 Ignition coil check
1) Replace ignition coil for No.1 and No.4 spark plugs with
ignition coil for No.2 and No.3 spark plugs.
Is the cylinder found as faulty in good condition now? Faulty ignition coil. Go to Step 5.
5 Ignition coil output circuit check
1) Disconnect connectors from ECM.
2) Check ignition coil circuit of the cylinder found as faulty
in Step 2 for the following.
• Resistance of output wire circuit between ignition coil
connector and ECM connector is less than 2 Ω.
• Resistance of output wire circuit between ignition coil connector and vehicle b ody ground is infinity.
Are they in good condition? Substitute a known-
good ECM and recheck.
Repair or replace
defective wire.
Downloaded from www.Manualslib.com manuals search engine Engine General Information and Diagnosis: 1A-119
DTC Troubleshooting
NOTE
• When measuring circuit voltage, resistance and/or pulse signal at ECM connector, connect the
special tool to ECM and/or the ECM connectors re ferring to “Inspection of ECM and Its Circuits”.
• Upon completion of inspection and repair work, perform “DTC Confirmation Procedure” and confirm that the trouble has been corrected.
Step Action YesNo
1 Was “Engine and Emission Control System Check”
performed? Go to Step 2.
Go to “Engine and
Emission Control
System Description”.
2 EGR valve power supply circuit check
1) Remove air intake pipe.
2) With ignition switch turned OFF, disconnect EGR valve
connector.
3) With ignition switch turned ON, measure voltage between “BLK/RED” wire terminal of EGR valve
connector and vehicle body ground.
Is check voltage 10 – 14 V? Go to Step 3.
“BLK/RED” wire is open
circuit.
3 Wire circuit check
1) Disconnect connectors from ECM with ignition switch
turned OFF.
2) Turn ON ignition switch.
3) Measure voltage between engine ground and each “GRN/RED”, “GRN/ORN”, “W HT/RED”, “BRN/YEL” wire
terminals of EGR valve connector.
Is each voltage 0 V? Go to Step 4.
Faulty wire(s) are
shorted to other circuit.
If wires are OK,
substitute a known-
good ECM and recheck.
4 Wire circuit check
1) With ignition switch turned OFF, measure resistance
between engine ground and each “GRN/RED”, “GRN/
ORN”, “WHT/RED”, “BRN/YEL” wire terminals of EGR
valve connector.
Is resistance infinity? Go to Step 5.
Faulty wire(s) are
shorted to ground
circuit.
If wires are OK,
substitute a known-
good ECM and recheck.
5 Short circuit check for EGR valve control circuit
1) With ignition turned OFF, measure resistance between
each EGR valve control circ uit wire (“GRN/RED”, “GRN/
ORN”, “WHT/RED” and “BRN/ YEL” wire) and each EGR
valve control circuit wire.
Is each resistance infinity? Go to Step 6.
Faulty wire(s) are short
circuit.
6 EGR valve stepper motor coil circuit check
1) With ignition switch turned OFF, connect EGR valve
connector.
2) Measure resistance between “E23-1/16” and each “C37- 4”, “C37-3”, “C37-19”, “C37-18” terminals of ECM
connector.
Is each resistance 20 – 31
Ω at 20 °C, 68 °F? Faulty ECM. Substitute
a known-good ECM and
recheck.
Go to Step 7.
7 EGR valve check
1) Check EGR valve resistance referring to “EGR Valve
Inspection in Section 1B”.
Is resistance within specified value? Faulty wire(s) are open
or high resistance
circuit. If wires are OK,
substitute a known-
good ECM and recheck.Faulty EGR valve.
Downloaded from www.Manualslib.com manuals search engine Engine General Information and Diagnosis: 1A-123
DTC Confirmation Procedure
WARNING!
• When performing a road test, select a place where there is no traffic or possibility of a traffic accident and be very careful during testing to avoid occurrence of an accident.
• Road test should be carried out by 2 persons, a driver and a tester, on a level road.
1) With ignition switch OFF, connect scan tool to DLC.
2) Turn ON ignition switch and clear DTC using scan tool.
3) Start engine and warm up normal operating temperature.
4) Drive vehicle at more than 40 km/h, 25 mph for 5 min. or more.
5) Check DTC and pending DTC.
DTC Troubleshooting
WARNING!
In order to reduce risk of fire and personal injury, this work must be performed in a well ventilated area
and away from any open flames such as gas water heater.
NOTE
• When measuring circuit voltage, resistance and/ or pulse signal at ECM connector, connect the
special tool to ECM and/or the ECM connectors re ferring to “Inspection of ECM and Its Circuits”.
• Upon completion of inspection and repair work, perform “DTC Confirmation Procedure” and confirm that the trouble has been corrected.
Step Action YesNo
1 Was “Engine and Emission Control System Check”
performed? Go to Step 2.
Go to “Engine and
Emission Control
System Check”.
2 EVAP canister purge power supply circuit check
1) Turn OFF ignition switch and disconnect connector from
EVAP canister purge valve.
2) Measure voltage between engine ground and “BLK/ RED” wire terminal of EVAP canister purge valve
connector with ignition switch turned ON.
Is it voltage 10 – 14 V? Go to Step 3.
“BLK/RED” wire is open
circuit.
3 Wire circuit check
1) Disconnect connectors from ECM with ignition switch
turned OFF.
2) Measure resistance between “C37-29” terminal of ECM connector and vehicle body ground.
Is resistance infinity? Go to Step 4.
“BLU/BLK” wire is
shorted to ground
circuit.
4 Wire circuit check
1) Measure voltage between “C37-29” terminal of ECM
connector and vehicle body ground with ignition switch
turned ON.
Is voltage 0 V? Go to Step 5.
“BLU/BLK” wire is
shorted to other circuit.
Downloaded from www.Manualslib.com manuals search engine 1A-124 Engine General Information and Diagnosis:
DTC P0480: Fan 1 (Radiator Cooling Fan) Control CircuitS7RS0B1104050
Wiring Diagram5
Wire circuit check
1) Connect connector to purge control valve with ignition
switch turned OFF.
2) Turn ON ignition switch and measure voltage between “C37-29” terminal of ECM connector and vehicle body
ground.
Is it voltage 10 – 14 V? Go to Step 6. “BLU/BLK” wire is open
circuit.
6 EVAP canister purge control valve check
1) Check EVAP canister purge control valve referring to
“EVAP Canister Purge Valve Inspection in Section 1B”.
Is it in good condition? Go to Step 7. Faulty EVAP canister
purge control valve.
7 EVAP canister purge control circuit check
1) With ignition switch turn OFF, measure resistance
between “E23-1/16” terminal and “C37-29” terminal of
ECM connector.
Is resistance below 40
Ω at 20 °C, 68 °F? Faulty ECM. Substitute
a known-good ECM and
recheck.
“BLK/RED” and/or
“BLU/BLK” wire are high
resistance circuit.
Step Action Yes No
E23
C37
34
1819
567
1011
17
20
47 46
495051
2122
52 16
25 9
24
14
29
55
57 54 53
59
60 58 2
262728
15
30
56 4832 31
34353637
40
42 39 38
44
45 43 41 331
1213
238
34
1819
567
1011
17
20
47 46
495051
2122
52 16
25 9
24
14
29
55
57 54 53
59
60 58 2
262728
15
30
56 4832 31
34353637
40
42 39 38
44
45 43 41 331
1213
238
BLK/REDBLK/RED
BLK/YELBLK/YEL
BLK/YEL
BRN/WHT
12V
5V5V
2
8
E23-1
E23-60
C37-58
C37-15 C37-30
BLK/ORN
BLKBLKE23-31BLK
BLK/RED
LT GRN
BLK/REDE23-16
E23-46
L+
L–
H–
H
+
BLU/RED
BLK
BLUWHTBLK
BLU/BLK
BLU/RED
4
GRN
GRY
E23-48
LT GRN
ORN
C37-24
C37-55
35
6
7
10
9
1
I6RS0C110022-02
1. Individual circuit fuse box No.1
5. Radiator cooling fan relay No. 3 9. “FI” fuse
2. Main relay 6. Radiator cooling fan motor10. “RDTR FAN” fuse
3. Radiator cooling fan relay No. 1 7. ECT sensor
4. Radiator cooling fan relay No. 2 8. ECM
Downloaded from www.Manualslib.com manuals search engine 1A-126 Engine General Information and Diagnosis:
3Wire circuit check
1) Disconnect radiator cooling fan relay No. 1 (1) from
individual circuit fuse box No .1 (2) with ignition switch
turned OFF.
2) Turn ON ignition switch, measure voltage between each engine ground to “BLK/RED” and “GRY” wire terminal.
Is voltage 10 – 14 V? Go to Step 4. Open wire in “BLK/RED”
and/or “GRY” wire are
open circuit.
4 Wire circuit check
1) Connect radiator cooling fan relay No. 1 to individual
circuit fuse box No.1 with ignition switch turned OFF.
2) Remove ECM from its br acket with ECM connectors
connected.
3) Turn ON ignition switch, ma ke sure that A/C switch is
OFF position.
4) Measure voltage between vehicle body ground and “E23-46” terminal of ECM connector when engine
coolant temp. is below 95 °C, 203 °F.
Is voltage 10 – 14 V? Go to Step 8.
Go to Step 5.
5 Wire circuit check
1) Disconnect connectors from ECM with ignition switch
turned OFF.
2) Disconnect radiator cooling fan relay No. 1 from individual circuit fuse box No.1.
3) Measure resistance between “E23-46” terminal of ECM connector and vehicle ground.
Is resistance infinity? Go to Step 6.
“LT GRN” wire is
shorted to ground
circuit.
6 Wire circuit check
1) Turn ON ignition switch.
2) Measure voltage between “E23-46” terminal of ECM
connector and vehicle body ground.
Is voltage 0 V? Go to Step 7.
“LT GRN” wire is
shorted to other circuit.
7 Radiator cooling fan relay No. 1 check
1) Check radiator cooling fan relay No. 1 referring to
“Radiator Cooling Fan Relay Inspection in Section 1F”.
Is check result satisfactory? “LT GRN” wire is open
circuit.
Replace relay.
Step
Action YesNo
1
2
I7RS0A110010-01