Page 249 of 1496

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.  
         
        
        
     
        
        Page 250 of 1496
Downloaded from www.Manualslib.com manuals search engine 1A-200 Engine General Information and Diagnosis: 
Fuel Pump and Its Circuit CheckS7RS0B1104082
Wiring Diagram
E23-1
E23-60
E23-15
BRN/WHT
BLK/REDBLK/YEL
BLK/YEL
BLK/RED
E23-29BLK/WHT
GRN/WHT
BLK/WHT
BLK/WHT
PNK
BLK
WHT
GRN
C37-58
C37-15
C37-30
BLK/ORN
BLK
BLKE23-31BLK
78
9 6
4 3
2 5
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 48 32 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/YEL
1
E23-16BLK/RED
BLK/RED
I6RS0C110041-01
1. Main fuse box 4. Fuel pump relay 7. Ignition switch
2. Main relay 5. Fuel pump 8. “FI” fuse
3. ECM 6. “IG COIL” fuse 9. “IG ACC” fuse  
         
        
        
     
        
        Page 251 of 1496

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  
         
        
        
     
        
        Page 252 of 1496

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  
         
        
        
     
        
        Page 253 of 1496
Downloaded from www.Manualslib.com manuals search engine Engine General Information and Diagnosis:  1A-203
Fuel Pressure CheckS7RS0B1104083
System Diagram
Special tool
(A):  09912–58442
(B):  09912–58432
(C):  09912–58490
I3RM0A110081-01
1. Injector2. Delivery pipe 3. Fuel filter and fuel pump  
         
        
        
     
        
        Page 254 of 1496

Downloaded from www.Manualslib.com manuals search engine 1A-204 Engine General Information and Diagnosis: 
Troubleshooting
NOTE
Before using following flow, check to make sure that battery voltage is higher than 11 V. If battery 
voltage is low, pressure becomes lower than specification even if fuel pump and line are in good 
condition.
 
StepAction YesNo
1 Fuel pressure check
1) Check fuel pressure referring to “Fuel Pressure 
Inspection in Section 1G”.
Is check result satisfactory? Go to Step 2.
Go to Step 5.
2 Fuel pressure check
1) Start engine and warm it up to normal operating 
temperature.
2) Keep engine speed at 4000 rpm.
Does fuel pressure show about the same value as Step 1? Go to Step 3.
Go to Step 8.
3 Fuel line check
1) Check fuel pipe, fuel hose and joint for fuel leakage.
Are they in good condition? Go to Step 4.
Repair or replace 
defective part.
4 Fuel line check
1) Check fuel pipe, fuel hose and joint for damage or 
deform.
Are they in good condition? Faulty fuel pressure 
regulator.
Repair or replace 
damaged or damaged 
part.
5 Was fuel pressure higher than specification in Step 1? Go to Step 6.Go to Step 7.
6 Fuel line check
1) Check fuel pipe, fuel hose and joint for damage or 
deform.
Are they in good condition? Faulty fuel pressure 
regulator.
Repair or replace 
damaged or damaged 
part.
7 Fuel pump operating sound check
1) Remove fuel filler cap and th en turn ON ignition switch.
Can you hear operating sound? Go to Step 8.
Faulty fuel pump.
8 Fuel line check
1) Check fuel pipe, fuel hose and joint for damage or 
deform.
Are they in good condition? Clogged fuel filter, faulty 
fuel pump, faulty fuel 
pressure regulator or 
fuel leakage from hose 
connection in fuel tank.Repair or replace 
defective part.  
         
        
        
     
        
        Page 255 of 1496

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  
         
        
        
     
        
        Page 256 of 1496

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.