Downloaded from www.Manualslib.com manuals search engine Engine General Information and Diagnosis: 1A-177
C37-10 WHTOxygen signal of
HO2S-1 0 – 1 V Ignition switch turned ON.
—
*Deflects between
over 0.5 V and under 0.45 V
(“Reference
waveform No.10: ” and “Reference
waveform No.11: ”) While engine running at
2,000 r/min. for 1 min. or
longer after warmed up.
C37-11 BRN Oxygen signal of
HO2S-2 4 – 5 V Ignition switch turned ON.
—
*Deflects between
over 0.5 V and under 0.45 V
(“Reference
waveform No.12: ”) While engine running at
2,000 r/min. or more after
vehicle running over 30
km/h, 19 mph for 5 min.
C37-12 WHT CAN (low)
(communication
line (active low
signal) to TCM (A/T
model) *0.5 – 2.5 V
(“Reference
waveform No.13: ”) Ignition switch turned ON
with engine stop. CAN communication line
signal is pulse. Pulse
signal displayed with a
regular frequency which
varies depending on
engine condition.
C37-13 RED CAN (high)
communication line
(active high signal)
to TCM (A/T
model) *2.5 – 4.5 V
(“Reference
waveform No.13: ”)
C37-14 GRY/
RED Output of 5 V
power source for
MAP sensor, A/C
refrigerant
pressure sensor
4.5 – 5.5 V Ignition switch turned ON. —
C37-15 BLK Ground for ECM Below 0.3 V Ignition switch turned ON. —
C37-16 BLU/
RED Fuel injector No.3
output 10 – 14 V Ignition switch turned ON. —
*0 – 0.6 V ↑↓
10 – 14 V
(“Reference
waveform No.1: ” and
“Reference waveform No.14: ”) Engine running at idle
after warmed up engine.
Output signal is active low
pulse. Pulse frequency
varies depending on
engine speed.
C37-17 BLU/
ORNFuel injector No.4
output 10 – 14 V Ignition switch turned ON. —
*0 – 0.6 V ↑↓
10 – 14 V
(“Reference
waveform No.1: ” and
“Reference waveform No.15: ”) Engine running at idle
after warmed up engine.
Output signal is active low
pulse. Pulse frequency
varies depending on
engine speed.
C37-18 BRN/
YEL EGR valve
(stepper motor coil
4) output 10 – 14 V Ignition switch turned ON. —
*0 – 1 V ↑↓
10 – 14 V
(“Reference
waveform No.4: ”) Ignition switch is turned to
ST (cranking) position. Output signal is active low
duty pulse. Number of
pulse generated times
varies depending on
vehicle condition.
C37-19 WHT/
RED EGR valve
(stepper motor coil
3) output 10 – 14 V Ignition switch turned ON. —
*0 – 1 V ↑↓
1
0 – 14 V
(“Reference
waveform No.4: ”) Ignition switch is turned to
ST (cranking) position. Output signal is active low
duty pulse. Number of
pulse generated times
varies depending on
vehicle condition.
Terminal
No. Wire
color Circuit Normal voltage
ConditionRemarks
Downloaded from www.Manualslib.com manuals search engine 1A-180 Engine General Information and Diagnosis:
C37-50 —Ground of ECM for
shield wire Below 0.3 V Ignition switch turned ON. —
C37-51 — Ground of ECM for
shield wire Below 0.3 V Ignition switch turned ON. —
C37-52 — Ground of ECM for
shield wire Below 0.3 V Ignition switch turned ON. —
C37-53 RED/
BLK MAP sensor signal Approx. 4 V
(“Reference
waveform No.23: ”) Ignition switch turned ON
with barometric pressure
at 100 kPa, 760 mmHg.
—
0.4 – 2.0 V
(“Reference
waveform No.24: ”) While engine running at
specified idle speed after
warmed up with
barometric pressure at
100 kPa, 760 mmHg.
C37-54 GRN TP sensor (main)
signal 0.75 – 1.08 V
Ignition switch turned ON
and accelerator pedal at
idle position after warmed
up engine.
—
3.67 – 4.24 V Ignition switch turned ON
and accelerator pedal at
full depressed position
after warmed up engine.
C37-55 ORN Ground for sensors Below 0.3 V Ignition switch turned ON. —
C37-56 RED Knock sensor
signal 2 – 3 V
(“Reference
waveform No.25: ” and “Reference
waveform No.26: ”) Ignition switch turned ON.
—
Engine running at 4000 r/
min. after warmed up.
C37-57 YEL Ground for sensors Below 0.3 V Ignition switch turned ON. —
C37-58 BLK/
ORN Ground for ECM Below 0.3 V Ignition switch turned ON.
—
C37-59 YEL/
GRN Oil control valve
ground
Below 1.3 V Ignition switch turned ON.
—
C37-60 YEL/
RED Oil control valve
output *0 – 0.6 V
↑↓
10 – 14 V
(“Reference
waveform No.27: ” and “Reference
waveform No.28: ”) At the moment of ignition
switch turned ON.
Output signal is active
high pulse. Duty ratio
varies depending on
vehicle condition.
Terminal
No. Wire
color Circuit Normal voltage
ConditionRemarks
Terminal
No. Wire
color Circuit Normal voltage Condition Remarks
E23-1 BLK/
RED Main power supply 10 – 14 V Ignition switch turned ON. —
E23-2 WHT/
RED Power source for
ECM internal
memory
10 – 14 V Ignition switch turned ON. —
E23-3 RED CAN (high)
communication line
(active high signal)
for ABS control
module, BCM,
combination meter *2.5 – 4.5 V
(“Reference
waveform No.29: ”) Ignition switch turned ON
with engine at stop. CAN communication line
signal is pulse. Pulse
signal displayed with a
regular frequency with
varies depending on
engine condition.
Downloaded from www.Manualslib.com manuals search engine 1A-182 Engine General Information and Diagnosis:
E23-25 PPLVehicle speed
signal output for P/
S control module *0 – 1 V
↑↓
10 – 14 V
(“Reference
waveform No.32: ”) Vehicle running. Sensor signal is pulse.
Pulse frequency varies
depending on vehicle
speed.
(21 pulses are generated
per sec. at 30 km/h, 19
mph.) (2561 pulses/km)
E23-26 RED/
BLU EPS signal 10 – 14 V Ignition switch turned ON.
—
0 – 1 V With engine running at idle
speed, and steering wheel
turned to the right or left as
far as it stops.
E23-27 — — — — —
E23-28 YEL/
BLK Serial
communication line
for immobilizer coil
antenna
10 – 14 V Ignition switch turned ON. —
E23-29 BLK/
WHT Ignition switch
signal 0 – 1 V Ignition switch turned OFF.
—
10 – 14 V Ignition switch turned ON.
E23-30 WHT Starting motor
control relay output 0 – 1 V Ignition switch turned ON.
—
0 – 1 V Ignition switch is turned to
ST (engine cranking)
position.
E23-31 BLK Ground for ECM Below 0.3 V Ignition switch turned ON. —
E23-32 RED/
YEL Power supply of
throttle actuator
drive circuit
10 – 14 V Ignition switch turned ON. —
E23-33 — — — — —
E23-34 RED Output for 5 V
power source of
APP sensor (sub) 4.5 – 5.5 V Ignition switch turned ON. —
E23-35 BRN Output for 5 V
power source of
APP sensor (main) 4.5 – 5.5 V Ignition switch turned ON. —
E23-36 YEL APP sensor (sub)
signal 1.55 – 1.65 V
Ignition switch turned ON
and accelerator pedal at
idle position after warmed
up engine.
—
4.18 – 5.12 V Ignition switch turned ON
and accelerator pedal at
full depressed position
after warmed up engine.
E23-37 YEL APP sensor (main)
signal 0.75 – 0.85 V
Ignition switch turned ON
and accelerator pedal at
idle position after warmed
up engine.
—
3.46 – 4.24 V Ignition switch turned ON
and accelerator pedal at
full depressed position
after warmed up engine.
E23-38 — — — — —
E23-39 — — — — —
E23-40 — — — — —
E23-41 — — — — —
E23-42 — — — — —
E23-43 — — — — —
E23-44 — — — — —
Terminal
No. Wire
color Circuit Normal voltage Condition Remarks
Downloaded from www.Manualslib.com manuals search engine 1A-194 Engine General Information and Diagnosis:
ECM Power and Ground Circuit CheckS7RS0B1104080
Wiring DiagramC37-3 to E23-1/16 EGR valve
(stepping motor No.2 coil)
20 – 31 Ω —
C37-18 to E23-1/16 EGR valv e (stepping motor No.4 coil)
C37-19 to E23-1/16 EGR valv e (stepping motor No.3 coil)
C37-46 to E23-29 Heater of HO2S-1 2 – 11 Ω—
C37-1 to E23-1/16 No.1 fuel injector 10.8 – 18.2 Ω —
E23-47 to E23-1/16 A/C compressor relay 160 – 240 Ω —
C37-60 to C37-59 Oil control valve 6 – 15 Ω —
E23-45 to E23-1/16 Throttle actuator control relay 160 – 240 Ω —
Terminals
CircuitStandard resistance Condition
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/RED
BLK/REDBLK/RED
BLK/YELBLK/YEL
BLK/YEL
GRN
BRN/WHT
12V
5VE23-1
E23-60
E23-16
WHT 2
4
11
6
3
12
13 14
7
1
16
17
89
15
10
5
WHT/REDE23-2
C37-58
C37-15C37-30
BLK/ORN
BLKBLKE23-31BLK
WHT
GRY/REDRED/BLK
ORN
C37-14C37-53
C37-55E23-54
REDE23-55
GRNBRN
BLU
REDYELWHT
E23-35E23-37E23-52
E23-51
E23-34E23-36
E23-50
LT GRN/REDLT GRN/BLKC37-45C37-44
C37-43
C37-54C37-40C37-42C37-41
RED
GRN
WHTBLK
ORN
BLK/WHTE23-29
I6RS0C110039-01
1. Main fuse box 7. Individual circuit fuse box No.1 13. A/C refrigerant pressure sensor (if equipped with A/C)
2. Ignition switch 8. “IG ACC” fuse14. APP sensor (main)
3. Main relay 9. “FI” fuse15. APP sensor (sub)
4. BCM (included in junction block assembly) 10. “RADIO” fuse 16. TP sensor (main)
5. “IG COIL” fuse 11. DLC17. TP sensor (sub)
6. ECM 12. MAP sensor
Downloaded from www.Manualslib.com manuals search engine Engine General Information and Diagnosis: 1A-195
Circuit Description
When the ignition switch is turned ON, the main relay turns ON (the contact point closes) and the main power is
supplied to ECM.
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 referri ng to “Inspection of ECM and Its Circuits”.
StepAction YesNo
1 Circuit fuse check
1) Disconnect connectors from ECM with ignition switch
turned OFF.
2) Check for proper connection to ECM connector at “E23- 2”, “E23-29”, “E23-60”, “E23-1”, “E23-16”, “E23-31”,
“C37-58”, “C37-15” and “C37-30” terminals.
3) If OK, check “RADIO” fuse and “IG COIL” fuse for blowing.
Are “RADIO” fuse and “IG COIL” fuse in good condition? Go to Step 2.
Replace fuse (s) and
check for short in
circuits connected to
fuse(s).
2 Power supply circuit check
1) Measure voltage between “E23-2” terminal of ECM
connector and body ground.
Is voltage 10 – 14 V? Go to Step 3.
“WHT/RED” or “WHT”
wire is open circuit.
3 Ignition signal check
1) Turn ignition switch to ON position.
2) Measure voltage between “E23-29” terminal of ECM
connector and body ground.
Is voltage 10 – 14 V? Go to Step 4.
“BLK/WHT” or “GRN”
wire is open circuit.
4 Main relay circuit check
1) Turn ignition switch to OFF position.
2) Check “FI” fuse (1) in indivi dual circuit fuse box No.1 for
blowing.
3) If OK, measure voltage between “E23-60” terminal of ECM connector and body ground.
Is voltage 10 – 14 V? Go to Step 5.
Go to Step 9.
1
I4RS0A110016-01
Downloaded from www.Manualslib.com manuals search engine Engine General Information and Diagnosis: 1A-197
10Main relay check
1) Check main relay referring to “Main Relay, Fuel Pump
Relay and Starting Motor Control Relay Inspection in
Section 1C”.
Is main relay in good condition? “BRN/WHT” wire is
open or high resistance
circuit.
Replace main relay.
11 Sensor power source circuit check
1) Connect connectors to ECM with ignition switch turned
OFF.
2) Turn ON ignition switch, measure each voltage between “C37-14”, “E23-35”, “E23-34” and “C37-43” terminals of
ECM connector and vehicle body ground.
Is each voltage 4 – 6 V? ECM power and ground
circuit is in good
condition.
Go to Step 12.
12 Sensor power source circuit check
1) Disconnect connectors from ECM, TP sensor, APP
sensor, MAP sensor and A/C refrigerant pressure sensor
(if equipped with A/C) with i gnition switch turned OFF.
2) Measure each resistance between “C37-14”, “E23-35”, “E23-34” and “C37-43” terminals of ECM connector and
vehicle body ground.
Is each resistance infinity? Check internal short
circuit of TP sensor,
APP sensor, MAP
sensor and/or A/C
refrigerant pressure
sensor (if equipped with
A/C).
“GRY/RED” wire is
shorted to ground
circuit.
Step Action Yes No
Downloaded from www.Manualslib.com manuals search engine Engine General Information and Diagnosis: 1A-199
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 referri ng to “Inspection of ECM and Its Circuits”.
StepAction YesNo
1 Fuel injector check for operating sound
1) Using sound scope, check each injector for operating
sound at engine cranking.
Do all 4 injector ma ke operating sound? Fuel injectors circuit is
in good condition.
Go to Step 2.
2 Fuel injector resistance check
1) Disconnect connectors from fuel injectors with ignition
switch turned OFF.
2) Check for proper connection to fuel injector at each terminals.
3) If OK, check all 4 fuel inject ors for resistance referring to
“Fuel Injector On-Vehicle Inspection in Section 1G”.
Are all injectors in good condition? Go to Step 3.
Faulty fuel injector.
3 Fuel injector insulation resistance check
1) Check that there is insulation between each fuel injector
terminal and engine ground.
Is there insulation? Go to Step 4.
Faulty fuel injector.
4 Fuel injector power supply check
1) Measure voltage between each “BLK/RED” wire terminal
of fuel injector connector and engine ground with ignition
switch turned ON.
Is voltage 10 – 14 V? Go to Step 5.
“BLK/RED” wire is open
or shorted to ground
circuit.
If it is in good condition,
go to “ECM Power and
Ground Circuit Check”.
5 Wire circuit check
1) Turn OFF ignition switch.
2) Disconnect connectors from ECM.
3) Measure resistance between each “BLU/YEL”, “BLU/
WHT”, “BLU/RED”, “BLU/ORN” wire terminal of fuel
injector connector and vehicle body ground.
Is resistance infinity? Go to Step 6.
“BLU/YEL”, “BLU/WHT”,
“BLU/RED” and/or
“BLU/ORN” wire(s) are
shorted to ground.
6 Wire circuit check
1) Measure voltage between each “BLU/YEL”, “BLU/WHT”,
“BLU/RED”, “BLU/ORN” wire terminal of fuel injector
connector and vehicle body ground with ignition switch
turned ON.
Is voltage 0 V? Go to Step 7.
“BLU/YEL”, “BLU/WHT”,
“BLU/RED” and/or
“BLU/ORN” wire(s) are
shorted to power supply
circuit.
7 Fuel injector drive signal check
1) Connect connectors to each fuel injector and ECM with
ignition switch turned OFF.
2) Turn ON ignition switch.
3) Measure voltage between each “C37-1”, “C37-2”, “C37- 16”, “C37-17” terminal of ECM connector and vehicle
body ground.
Is voltage 10 – 14 V? Check fuel injector
referring to “Fuel
Injector Inspection in
Section 1G”.
If check result is
satisfactory, substitute a
known-good ECM and
recheck.
“BLU/YEL”, “BLU/WHT”,
“BLU/RED” and/or
“BLU/ORN” wire(s) are
open circuit.
Downloaded from www.Manualslib.com manuals search engine Engine General Information and Diagnosis: 1A-215
7Radiator cooling fan No. 2 wire circuit check
1) Turn ON ignition switch.
2) Measure voltage between “BLU/BLK” wire terminal of
disconnected radiator cooling fan control relay No. 2
connector and vehicle body ground.
Is voltage 0 V? Go to Step 8. “BLU/BLK” wire is
shorted to power supply
circuit.
8 Radiator cooling fan control No. 2 check
1) Connect radiator cooling fan control relay No. 2 to
individual circuit fuse box No.1 with ignition switch
turned OFF.
2) Run engine when ECT is over 102.5 °C, 216.5 °F.
3) Measure voltage between vehicle body ground and “BLU/BLK” wire terminal of disconnected radiator
cooling fan motor connector.
Is voltage 10 – 14 V? Go to Step 10. Go to Step 9.
9 Radiator cooling fan control relay No.2 check
1) Remove radiator cooling fan control relay No.2 with
ignition switch turned OFF.
2) Check radiator cooling fan control relay No.2 referring to “Radiator Cooling Fan Relay Inspection in Section 1F”.
Is it in good condition? “BLU/BLK” wire is open
or high resistance
circuit.
Faulty radiator cooling
fan control relay No.2.
10 Radiator cooling fan No. 3 wire circuit check
1) Remove radiator cooling fan control relay No.3 with
ignition switch turned OFF.
2) Measure resistance between vehicle body ground and “BLK” wire terminal of disconnected radiator cooling fan
control relay No. 3 connector in individual circuit fuse
box No.1.
Is resistance below 1
Ω? Go to Step 11. “BLK” wire is open or
high resistance circuit.
11 Radiator cooling fan control No. 3 check
1) Connect radiator cooling fan control relay No. 3 to
individual circuit fuse box No.1 with ignition switch
turned OFF.
2) Run engine when ECT is over 102.5 °C, 216.5 °F.
3) Measure resistance between vehicle body ground and “BLU/WHT” wire terminal of disconnected radiator
cooling fan motor connector.
Is resistance below 2
Ω? Go to Step 13. Go to Step 12.
12 Radiator cooling fan control relay No. 3 check
1) Remove radiator cooling fan control relay No.3 with
ignition switch turned OFF.
2) Check radiator cooling fan control relay No.3 referring to “Radiator Cooling Fan Relay Inspection in Section 1F”.
Is it in good condition? “BLU/WHT” wire is open
or high resistance
circuit.
Faulty radiator cooling
fan control relay No.3.
13 Radiator cooling fan check
1) Check radiator cooling fan referring to “Radiator Cooling
Fan Motor On-Vehicle Inspection in Section 1F”.
Is it in good condition? Substitute a known-
good ECM and recheck.
Faulty radiator cooling
fan.
Step
Action YesNo