Ground SUZUKI SWIFT 2008 2.G Service Owners Manual
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Page 222 of 1496

Downloaded from www.Manualslib.com manuals search engine 1A-172 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 APP sensor and its circuit check
1) Connect scan tool to DLC with ignition switch turned 
OFF.
2) Turn ON ignition switch.
3) Check each voltage of “APP Sensor 1 Volt” and “APP  Sensor 2 Volt” displayed on scan tool when accelerator 
pedal is idle position and fully depressed.
Is displayed each APP sensor value as described voltage in 
“Scan Tool Data”? Intermittent trouble.
Check for intermittent 
referring to “Intermittent 
and Poor Connection 
Inspection in Section 
00”.
Go to Step 3.
3 ECM voltage check
1) Disconnect connector from  APP sensor with ignition 
switch turned OFF.
2) Check for proper connection to APP sensor at “BRN”,  “GRN”, “BLU”, “RED”, “YEL” and “WHT” wire terminals.
3) If OK, measure voltage between “BRN” wire terminal of  APP sensor connector and vehicle body ground, 
between “RED” wire terminal  of APP sensor connector 
and vehicle body ground with ignition switch turned ON.
Is each voltage 4 – 6 V? Go to Step 6.
Go to Step 4.
4 Wire harness check
1) Disconnect connectors from ECM with ignition switch 
turned OFF.
2) Check for proper connection of ECM connector at “E23- 35” and “E23-34” terminals.
3) If OK, measure resistance between “E23-35” terminal of  ECM connector and engine ground, between “E23-34” 
terminal of ECM connector and engine ground.
Is each resistance infinity? Go to Step 5.
“BRN” wire or “RED” 
wire is shorted to other 
circuit.
5 Wire harness check
1) Measure voltage between “E23-35” terminal of ECM 
connector and engine ground, between “E23-34” 
terminal of ECM connector and engine ground with 
ignition switch turned ON.
Is each voltage 0 V? Substitute a known-
good ECM and recheck.
“BRN” wire or “RED” 
wire is shorted to other 
circuit.
"GRN"
"BLU"
"BRN"
"YEL"
"WHT"
"RED"
I4RS0B110048-01  
Page 223 of 1496

Downloaded from www.Manualslib.com manuals search engine Engine General Information and Diagnosis:  1A-173
DTC P2227 / P2228 / P2229: Barometric Pressure Circuit MalfunctionS7RS0B1104078
DTC P2227: Barometric Pressure Circuit Range / Performance
DTC P2228: Barometric Pressure Circuit Low
DTC P2229: Barometric Pressure Circuit High
System Description
Barometric pressure sensor is installed in ECM.
DTC Detecting Condition and Trouble Area6
Wire harness check
1) Disconnect connectors from ECM with ignition switch 
turned OFF.
2) Check for proper connection of ECM connector at “E23- 37”, “E23-52”, “E23-36” and “E23-51” terminals.
3) If OK, measure resistance between “GRN” wire terminal  of APP sensor connector  and vehicle body ground, 
between “YEL” wire terminal  of APP sensor connector 
and vehicle body ground.
Is each resistance infinity? Go to Step 7. “GRN” wire or “YEL” 
wire is shorted to other 
circuit.
7 Wire harness check
1) Turn ON ignition switch.
2) Measure voltage between “E23-37” terminal of ECM 
connector and engine ground, between “E23-36” 
terminal of ECM connector and engine ground.
Is each voltage 0 V? Go to Step 8. “GRN” wire or “YEL” 
wire is shorted to other 
circuit.
8 APP sensor check
1) Check APP sensor referring to “APP Sensor Assembly 
Inspection in Section 1C”.
Is output voltage within specified value? Substitute a known-
good ECM and recheck.
Replace APP sensor 
assembly.
Step Action Yes No
DTC detecting condition
Trouble area
DTC P2227:
Difference of barometric pressure value and intake manifold 
pressure value is higher than specified value while engine 
cranking.
(*2 driving cycle detection logic,  monitoring once par driving cycle) • Manifold absolute pressure sensor 
performance problem
• Barometric pressure sensor in ECM
DTC P2228:
Barometric pressure signal less than specified value is detected.
(1 driving cycle detection logic) • Barometric pressure sensor in ECM
DTC P2229:
Barometric pressure signal more than specified value is detected.
(1 driving cycle detection logic)  
Page 227 of 1496

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  
Page 228 of 1496

Downloaded from www.Manualslib.com manuals search engine 1A-178 Engine General Information and Diagnosis: 
C37-20RED/
YEL CMP sensor signal 0 – 1 V or 4 – 5 V Ignition switch turned ON. —
*0 – 0.6 V↑↓
4 – 5 V
(“Reference 
waveform No.16: ”  and “Reference 
waveform No.17: ”) Engine running at idle 
after warmed up engine.
Sensor signal is pulse. 
Pulse frequency varies 
depending on engine 
speed.
(6 pulses are generated 
per 1 camshaft revolution.)
C37-21 PNK CKP sensor signal 0 – 1 V or 4 – 5 V Ignition switch turned ON. —
*4 – 5 V↑↓
0 – 0.6 V
(“Reference 
waveform No.16: ”  and “Reference 
waveform No.17: ”) Engine running at idle 
after warmed up engine. Sensor signal is pulse. 
Pulse frequency varies 
depending on engine 
speed.
(30 (36 – 6) pulses are 
generated per 1 
crankshaft revolution.)
C37-22 — — — — —
C37-23 PNK/
BLU Electric load 
current sensor 
signal 3.8 – 4.2 V Ignition switch turned ON.
—
3.0 – 3.4 V
Ignition switch turned ON 
and headlight switch 
turned ON (HI beam).
2.3 – 2.7 V Ignition switch turned ON, 
headlight switch turned 
ON (HI beam) and blower 
selector at HI position.
C37-24 LT GRN ECT sensor signal 3.3 – 3.8 V
Ignition switch turned ON, 
ECT at 0 
°C, 32  °F.
—
1.38 – 1.72 V Ignition switch turned ON, 
ECT at 50 
°C, 122  °F.
0.40 – 0.53 V Ignition switch turned ON, 
ECT at 100 
°C, 212  °F.
C37-25 BLK/
YEL IAT sensor signal 3.18 – 3.67 V
Ignition switch turned ON, 
IAT at 0 
°C, 32  °F.
—
1.32 – 1.65 V Ignition switch turned ON, 
IAT at 40 
°C, 104  °F.
0.46 – 0.60 V Ignition switch turned ON, 
IAT at 80 
°C, 176  °F.
C37-26 GRN/
BLK MAF sensor signal 0.5 – 1.5 V
Ignition switch turned ON 
with engine at stop.
—
1.5 – 2.0 V
(“Reference 
waveform No.18: ”) Wh
en engine running at 
specified idle speed after 
warmed up.
C37-27 GRY Ground for MAF 
sensor Below 0.3 V Ignition switch turned ON.
—
C37-28 BLU/
YEL Generator control 
signal output *0 – 0.6 V
↑↓
5 – 8 V
(“Reference 
waveform No.19: ”) Engine running at idle 
speed, headlight switch 
turned ON.
Output signal is active low 
duty pulse. Duty ratio 
varies depending on 
vehicle condition.
C37-29 BLU/
BLK EVAP canister 
purge valve output 10 – 14 V
Ignition switch turned ON 
with engine at stop. —
*0 – 0.6 V ↑↓
10 – 14 V
(“Reference 
waveform No.20: ”) Set EVAP canister purge 
valve at 52% by using 
“Misc Test” of scan tool.
Output signal is active low 
duty pulse. Duty ratio 
varies depending on 
vehicle condition.
C37-30 BLK Ground for ECM Below 0.3 V Ignition switch turned ON. —
C37-31 — —— — —
Terminal 
No. Wire 
color Circuit Normal voltage
ConditionRemarks  
Page 229 of 1496

Downloaded from www.Manualslib.com manuals search engine Engine General Information and Diagnosis:  1A-179
C37-32 ——— — —
C37-33 — —— — —
C37-34 — —— — —
C37-35 — —— — —
C37-36 — —— — —
C37-37 — —— — —
C37-38 — —— — —
C37-39 — —— — —
C37-40 WHT TP sensor (sub) 
signal 1.57 – 1.09 V
Ignition switch turned ON 
and accelerator pedal at 
idle position after warmed 
up engine.
—
3.88 – 4.45 V Ignition switch turned ON 
and accelerator pedal at 
full depressed position 
after warmed up engine.
C37-41 — Ground for shield 
wire of TP sensor 
circuit Below 0.3 V Ignition switch turned ON.
—
C37-42 BLK Ground for TP 
sensor Below 0.3 V Ignition switch turned ON.
—
C37-43 RED Output for 5 V 
power source of TP 
sensor 4.5 – 5.5 V Ignition switch turned ON.
—
C37-44 LT  
GRN/ BLK Output of throttle 
actuator 0 – 1 V
Ignition switch turned ON 
and accelerator pedal at 
idle position after warmed 
up engine.
Output signal is pulse. 
Duty ratio varies 
depending on throttle 
valve and accelerator  pedal position.
*0 – 1 V
↑↓
10 – 14 V
(“Reference 
waveform No.21: ”) Ignition switch turned ON 
and accelerator pedal at 
full depressed position 
after warmed up engine.
C37-45 LT  
GRN/ RED Output of throttle 
actuator 0 – 1 V
Ignition switch turned ON 
and accelerator pedal at 
full depressed position 
after warmed up engine.
Output signal is pulse. 
Duty ratio varies 
depending on throttle 
valve and accelerator  pedal position.
*0 – 1 V
↑↓
10 – 14 V
(“Reference 
waveform No.21: ”) Ignition switch turned ON 
and accelerator pedal at 
idle position after warmed 
up engine.
C37-46 BLK/
RED Heater output of 
HO2S-1 10 – 14 V Ignition switch turned ON.
—
*0 – 2 V ↑↓
10 – 14 V
(“Reference 
waveform No.10: ”  and “Reference 
waveform No.11: ”) Engine running at idle 
after warmed up engine.
Output signal is active low 
duty pulse. Duty ratio 
varies depending on 
engine condition.
C37-47 RED/
BLU Heater output of 
HO2S-2 10 – 14 V Ignition switch turned ON.
—
0 – 1 V
(“Reference 
waveform No.12: ”) Engine running at idle 
after vehicle running over 
30 km/h, 19 mph for 5 min.
C37-48 YEL/
GRN Starting motor 
signal 0 – 1 V Ignition switch turned ON.
—
6 – 14 V While engine cranking.
C37-
49 — —— — —
Terminal 
No. Wire 
color Circuit Normal voltage
ConditionRemarks  
Page 230 of 1496

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.  
Page 232 of 1496

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  
Page 233 of 1496

Downloaded from www.Manualslib.com manuals search engine Engine General Information and Diagnosis:  1A-183
E23-45BLU/
ORNThrottle actuator 
control relay output
0 – 1 V Ignition switch turned ON. —
E23-46 LT GRN Radiator cooling 
fan relay No.1 
output 10 – 14 V
Ignition switch turned ON, 
engine coolant temp.: 
below 95 
°C (203 ° F), or 
A/C refrigerant pressure (if 
equipped with A/C): below 
600 kPa (87 psi) with A/C 
switch turned ON while 
engine is running. —
0 – 2 V Ignition switch turned ON, 
engine coolant temp.: 97.5 
°
C (207.5 ° F) or higher, or 
A/C refrigerant pressure (if 
equipped with A/C): 1100 
kPa (159.5 psi) or higher 
with A/C switch turned ON 
while engine is running.
E23-47 GRY A/C compressor 
relay output  10 – 14 V
Engine running, A/C 
switch OFF and blower 
selector at OFF position.
—
0 – 1 V Engine running, A/C 
switch ON and blower 
selector at 1st position or 
more.
E23-48 GRN Radiator cooling 
fan relay No.2 and 
No.3 output 10 – 14 V
Ignition switch turned ON, 
engine coolant temp.: 
below 100 
°C (212  °F), or 
A/C refrigerant pressure (if 
equipped with A/C): below 
1200 kPa (174 psi) with A/
C switch turned ON while 
engine is running. —
0 – 2 V Ignition switch turned ON, 
engine coolant temp.: 
102.5 
°C (216.5  °F) or 
higher, or A/C refrigerant 
pressure (if equipped with 
A/C): 1500 kPa (217.5 psi) 
or higher with A/C switch 
turned ON while engine is 
running.
E23-49 — — — — —
E23-50 — Ground for shield 
wire of APP sensor Below 0.3 V Ignition switch turned ON. —
E23-51 WHT Ground for APP 
sensor (sub) Below 0.3 V Ignition switch turned ON. —
E23-52 BLU Ground for APP 
sensor (main) Below 0.3 V Ignition switch turned ON. —
E23-53 — — — — —
E23-54 ORN Ground for sensors Below 0.3 V Ignition switch turned ON. —
Terminal 
No. Wire 
color Circuit Normal voltage Condition Remarks  
Page 244 of 1496

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  
Page 245 of 1496

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