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-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-201
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 pump control system check for operation
Is fuel pump heard to operate 2 sec. after ignition switch is
turned ON? Fuel pump circuit is in
good condition.
Go to Step 2.
2 Fuel pump relay po wer supply check
1) Disconnect fuel pump relay from individual circuit fuse box No.1 with ignition switch turned OFF.
2) Check for proper connection to fuel pump relay at each terminal.
3) If OK, turn ON ignition switch, measure voltage between “BLK/WHT” wire terminal of fuel pump relay connector
and engine ground.
Is voltage 10 – 14 V? Go to Step 3.
“BLK/WHT” wire is open
or shorted to ground
circuit.
3 Fuel pump relay po wer supply check
1) Turn ON ignition switch, measure voltage between “BLK/ RED” wire terminal of fuel pump relay connector and
engine ground.
Is voltage 10 – 14 V? Go to Step 4.
“BLK/RED” wire is open
circuit.
4 Fuel pump relay check
1) Check fuel pump relay referring to “Main Relay, Fuel
Pump Relay and Starting Moto r Control Relay Inspection
in Section 1C”.
Is relay in good condition? Go to Step 5.
Faulty relay.
5 Fuel pump relay drive signal check
1) Connect fuel pump relay to individual circuit fuse box
No.1.
2) Connect voltmeter between “E23-15” terminal of ECM connector and vehicle body ground.
3) Measure voltage 2 second after ignition switch is turned ON.
Is voltage 10 – 14 V? Go to Step 6.
“GRN/WHT” wire is
open circuit or shorted
to ground circuit.
I2RH01110132-01
Downloaded from www.Manualslib.com manuals search engine 1A-202 Engine General Information and Diagnosis:
6Fuel pump relay drive signal check
1) Measure voltage within 2 second after ignition switch is
turned ON.
Is voltage 0 – 1 V? Go to Step 7. Substitute a known-
good ECM and recheck.
7 Wire circuit check
1) Turn OFF ignition switch.
2) Detach fuel tank referring to “Fuel Tank Removal and
Installation in Section 1G”.
3) Disconnect connector from fuel pump.
4) Measure resistance between “PNK” wire terminal of fuel pump connector and vehicle body ground.
Is resistance infinity? Go to Step 8. “PNK” wire is shorted to
ground.
8 Fuel pump circuit check
1) Connect service wire between “E23-15” terminal of ECM
connector and vehicle body ground.
2) Turn ON ignition switch, measure voltage between “PNK” terminal at fuel pump connector and vehicle body
ground.
Is voltage 10 – 14 V? Go to Step 9. “PNK” wire is open
circuit.
9 Fuel pump circuit check
1) Turn OFF ignition switch.
2) Measure resistance between “BLK” wire terminal at fuel
pump connector and vehicle body ground.
Is resistance less than 5
Ω? Faulty fuel pump. “BLK” wire is open
circuit.
Step Action Yes No
Downloaded from www.Manualslib.com manuals search engine Engine General Information and Diagnosis: 1A-205
A/C System Circuits CheckS7RS0B1104084
Wiring Diagram
E23C37
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
5V
12
E23-1
E23-60
BLK/RED
LT GRN
BLK/REDE23-16
E23-46
L+
L–
H–
H
+
BLU/RED
BLK
BLUWHTBLK
BLU/BLK
BLU/RED
GRN
GRY
E23-48
8
11
2
3BLU/WHT
REDWHTREDWHTE23-3E23-18
E23-19
6
BLK
WHT
BLK 12V
E23-47 GRY
WHT
YELBLU
WHT
BLK/YEL
RED/BLK
GRN/WHT
WHT/BLU1
713
14
5V
5V
4
E23-55C37-14GRY/REDRED
E23-54ORN 5V
E23-57WHT/BLK16
9
10
25
17
5
24
15
22
BLU/YEL
23212019
GRN
BLK
18
26
28
27
I6RS0C110042-01
1. Blower fan motor 11. Radiator cooling fan motor 21. “A/C COMP” fuse
2. Blower fan switch 12. Main relay 22. “IG ACC” fuse
3. A/C switch 13. ECM 23. “RDTR FAN” fuse
4. A/C refrigerant pressure sensor 14. Ignition switch 24. Junction block assembly
5. Blower motor relay 15. BCM 25. “IG2 SIG” fuse
6. Compressor relay 16. Evaporator outlet air temp. sensor 26. HVAC control module
7. A/C compressor 17. “BACK” fuse 27. For manual A/C
8. Radiator cooling fan relay No.1 18. Individual circuit fuse box No.1 28. For automatic A/C
9. Radiator cooling fan relay No.2 19. “HTR FAN” fuse
10. Radiator cooling fan relay No.3 20. “FI” fuse
Downloaded from www.Manualslib.com manuals search engine 1A-206 Engine General Information and Diagnosis:
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”.
• When A/C evaporator outlet air temp. is below 2.5 °C (36.5 °F), A/C remains OFF (“E23-47” terminal
voltage becomes 10 – 14 V). This condition is not abnormal.
Step Action YesNo
1 Reception data check from BCM
1) Connect scan tool to DLC with ignition switch turned
OFF.
2) Turn ON ignition switch.
3) Check DTC for reception data from BCM.
Is there DTC P1678? Go to applicable DTC
diag. flow.
Go to Step 2.
2 A/C switch signal circuit check
1) Start engine and select “DATA LIST” mode on scan tool.
2) Check A/C switch signal under following conditions
respectively.
A/C switch signal
Engine running, A/C switch OFF: OFF
Engine running, A/C switch ON and blower speed
selector turned 1st position or more: ON
Is check result satisfactory? Go to Step 3. Check A/C switch
circuit.
3 DTC check of ECT sensor circuit
1) Check ECM for DTC of ECT sensor circuit.
Is there DTC P0116, DTC P0117 or DTC P0118? Go to applicable DTC
diag. flow.
Go to Step 4.
4 Radiator cooling fan control system check
Is radiator cooling fan started when A/C and blower speed
selector switch are turned ON with engine running? Go to Step 10. Go to Step 5.
5 Radiator cooling fan control circuit check
1) Check DTC with scan tool.
Is DTC P0480 displayed? Go to “DTC P0480: Fan
1 (Radiator Cooling
Fan) Control Circuit”.
Go to Step 6.
Downloaded from www.Manualslib.com manuals search engine Engine General Information and Diagnosis: 1A-209
Electric Load Signal Circuit CheckS7RS0B1104085
Wiring Diagram
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”.
BLK/WHT
BLK/RED
WHT
BRN/WHT
12V5V
11
BLK/YELBLK/YEL
BLK/YEL
BLKBLKBLK
BLK/ORN
10
18
17
BLU/WHT
15
WHTRED
43
YEL
5
13
BLK/WHT
BLKBLK/YEL
GRN
WHT
/BLU
BLU
16
2
6
7
12
8
9
BLK
WHT
RED
E23-29
E23-60
E23-1E23-16
E23-9
E23-3E23-18
C37-58C37-15
E23-31C37-30
BLK/RED
[A]
[B]
E23 C37
34
1819
567
10
11
17
20
47 46
495051
2122
52 16
25 9
24
14
29
5557 54 53
59
60 58 2
262728
15
30
56 4832 31
34353637
4042 39 38
44
45 43 41 331
1213
238
34
1819
567
10
11
17
20
47 46
495051
2122
52 16
25 9
24
14
29
5557 54 53
59
60 58 2
262728
15
30
56 4832 31
34353637
4042 39 38
44
45 43 41 331
12
13
238
1
14
I7RS0B110016-01
[A]: Manual A/C model
6. Ignition switch13. Blower motor
[B]: Auto A/C model 7. Junction block assembly14. HVAC control module
1. Main fuse 8. “IG COIL” fuse15. Blower speed selector
2. Individual circuit fuse box No.1 9. “IG2 SIG” fuse16. Electric load (rear defogger signal and headlight signal), etc.
3. “IG ACC” fuse 10. ECM17. BCM
4. “FI” fuse 11. Main relay18. ABS/ESP® control module
5. “HTR FAN” fuse 12. Blower motor relay
StepAction YesNo
1 DTC check
1) Connect scan tool to DLC with ignition switch turned
OFF.
2) Turn ON ignition switch and check DTC.
Is there any DTS(s) related to CAN? Go to applicable DTC
diag. flow.
Go to Step 2.
Downloaded from www.Manualslib.com manuals search engine 1A-210 Engine General Information and Diagnosis:
2Electric load signal circuit check
1) Start engine and select “Data List” mode on scan tool.
2) Check electric load signal under following conditions
respectively.
Blower fan signal (Manual A/C model)
Blower speed selector turned OFF or 1st position:
OFF
Blower speed selector turned to 2nd position or
more: ON
Blower fan signal (Auto A/C model)
Blower speed selector OFF or 4th position or less:
OFF
Blower speed selector turned to 6th position or
more: ON
Radiator fan signal
Engine coolant temperature is lower than 95 °C (103
° F): OFF
Engine coolant temperature is higher than 97.5 °C
(207.5 °F): ON
Electric load signal
Engine running, rear defogger switch, small light or
headlight switch OFF: OFF
Engine running, rear defogger switch, small light or
headlight switch ON: ON
Is check result satisfactory? Electric load signal
circuit is in good
condition.
Check defective signal
circuit.
Step Action Yes No