Vehicle speed signal SUZUKI SWIFT 2008 2.G Service Owner's Manual
Page 226 of 1496
Downloaded from www.Manualslib.com manuals search engine 1A-176 Engine General Information and Diagnosis: 
Terminal No. Wire 
color Circuit Normal voltage Condition Remarks
C37-1 BLU/
YEL Fuel injector No.1 
output 10 – 14 V Ignition switch turned ON. —
*0 – 0.6 V ↑↓
10 – 14 V
(“Reference 
waveform No.1: ”, 
“Reference waveform  No.2: ” and 
“Reference waveform  No.22: ”) Engine running at idle 
after warmed up engine.
Output signal is active low 
pulse. Pulse frequency 
varies depending on 
engine speed.
C37-2 BLU/
WHT Fuel injector No.2 
output 10 – 14 V Ignition switch turned ON. —
*0 – 0.6 V ↑↓
10 – 14 V
(“Reference 
waveform No.1: ” and 
“Reference waveform  No.3: ”) Engine running at idle 
after warmed up engine.
Output signal is active low 
pulse. Pulse frequency 
varies depending on 
engine speed.
C37-3 GRN/
ORN EGR valve 
(stepper motor coil 
2) 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.
C37-4 GRN/
RED EGR valve 
(stepper motor coil 
1) 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.
C37-5 GRN/
WHT Ignition coil No.2 
and No.3 output 0 – 0.6 V Ignition switch turned ON. —
*0 – 0.6 V ↑↓
3 – 5 V
(“Reference 
waveform No.5: ” and 
“Reference waveform  No.6: ”) Engine running at idle 
after warmed up engine.
Output signal is active 
high pulse. Pulse 
frequency varies 
depending on engine 
speed.
C37-6 GRN/
YEL Ignition coil No.1 
and No.4 output 0 – 0.6 V Ignition switch turned ON. —
*0 – 0.6 V ↑↓
3 – 5 V
(“Reference 
waveform No.6: ”, 
“Reference waveform  No.7: ” and 
“Reference waveform  No.22: ”
 )Engine running at idle 
after warmed up engine.
Output signal is active 
high pulse. Pulse 
frequency varies 
depending on engine 
speed.
C37-7 — —— — —
C37-8 BRN/
WHT Generator field coil 
monitor signal 10 – 14 V Ignition switch turned ON.
Signal is duty pulse. Duty 
ratio varies depending on 
vehicle condition.
*0 – 1 V
↑↓
10 – 14 V
(“Reference 
waveform No.8: ”) Engine running at idle 
after warmed up engine.
C37-9 — —— — —  
Page 227 of 1496
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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
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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 230 of 1496
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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
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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 237 of 1496
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Reference waveform No.10
HOS2-1 signal (1) with engine idling
Reference waveform No.11
HO2S-1 heater signal (2) with engine idlingReference waveform No.12
HO2S-2 heater signal (4) with engine idling
Reference waveform No.13
CAN communication line signal from TCM with ignition 
switch turned ON
Measurement 
terminal
CH1: “C37-10” to “C37-57”
CH2: “C37-46” to “C37-58”
Oscilloscope 
setting CH1: 500 mV/DIV, CH2: 20 V/DIV
TIME: 1 s/DIV
Measurement 
condition • After warmed up to normal 
operating temperature
• Engine at specified idle speed
2. HO2S-1 heater signal
Measurement 
terminal CH1: “C37-10” to “C37-57”
CH2: “C37-46” to “C37-58”
Oscilloscope 
setting CH1: 500 mV/DIV, CH2: 10 V/DIV
TIME: 200 ms/DIV
Measurement 
condition • After warmed up to normal 
operating temperature
• Engine at specified idle speed
1. HO2S-1 signal
3. OFF signal
4. ON signal
5. One duty cycle
I4RS0B110058-01
I4RS0B110059-01
Measurement 
terminal CH1: “C37-11” to “C37-57”
CH2: “C37-47” to “C37-58”
Oscilloscope 
setting CH1: 500 mV/DIV, CH2: 10 V/DIV
TIME: 2 s/DIV
Measurement 
condition • After warmed up to normal 
operating temperature
• Vehicle driving at 60 km/h (37  mph) for 10 min.
• Engine at specified idle speed
1. HO2S-2 signal upper limit
2. HO2S-2 signal lower limit
3. Normal waveform range
Measurement 
terminal CH1: “C37-13” to “C37-58”
CH2: “C37-12” to “C37-58”
Oscilloscope 
setting CH1: 1 V/DIV, CH2: 1 V/DIV
TIME: 40 
µs/DIV
Measurement 
condition Ignition switch turned ON
(Signal pattern is depending on 
engine condition)
1. CAN communication line signal (High)
2. CAN communication line signal (Low)
I4RS0B110060-01
I4RS0B110061-01  
Page 242 of 1496
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Reference waveform No.28
Oil control valve signal with engine racing
Reference waveform No.29
CAN communication line signal from each control 
module with ignition switch turned ONReference waveform No.30
Ignition pulse (engine revolution) signal (2) with engine 
idling
Reference waveform No.31
Ignition pulse (engine revolution) signal (2) with engine 
idling
Measurement 
terminal
CH1: “C37-60” to “C37-59”
Oscilloscope 
setting CH1: 5 V/DIV
TIME: 400 
µs/DIV
Measurement 
condition • After warmed up to normal 
operating temperature
• Vehicle driving at 20 km/h (12  mph) and depress accelerator 
pedal fully
1. Accelerator pedal depressed fully
2. Accelerator pedal depressed partially
3. Oil control valve signal
4. ON signal
5. OFF signal
Measurement 
terminal CH1: “E23-3” to “C37-58”
CH2: “E23-18” to “C37-58”
Oscilloscope 
setting CH1: 1 V/DIV, CH2: 1 V/DIV
TIME: 40 
µs/DIV
Measurement 
condition Ignition switch turned ON
(Signal pattern is depending on 
engine condition)
1. CAN communication line signal (High)
2. CAN communication line signal (Low)
I4RS0B110075-01
I4RS0B110076-01
Measurement 
terminal
CH1: “C37-20” to “C37-58”
CH2: “E23-4” to “C37-58”
Oscilloscope 
setting CH1: 5 V/DIV, CH2: 5 V/DIV
TIME: 40 ms/DIV
Measurement 
condition • After warmed up to normal 
operating temperature
• Engine at specified idle speed
1. Cylinder reference signal (CMP reference signal)
3. 720 ° crank angle
Measurement 
terminal CH1: “C37-20” to “C37-58”
CH2: “E23-4” to “C37-58”
Oscilloscope 
setting CH1: 5 V/DIV, CH2: 5 V/DIV
TIME: 10 ms/DIV
Measurement 
condition • After warmed up to normal 
operating temperature
• Engine at specified idle speed
1. Cylinder reference signal (CMP reference signal)
3. 360 ° crank angle
4. 2 to 4 msec.
5. 10 – 14 V
I6RS0C110036-01
I6RS0C110037-01  
Page 262 of 1496
Downloaded from www.Manualslib.com manuals search engine 1A-212 Engine General Information and Diagnosis: 
Troubleshooting
WARNING! 
Keep hands, tools, and clothing away from engine cooling fan to help prevent personal injury. This fan 
is electric and can come on whether or not the engi ne is running. The fan can start automatically in 
response to the ECT sensor with the ig nition switch at the “ON” position.
 
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 Is there DTC(s) of ECT sensor circuit (DTC P0116 / P0117 / 
P0118) and/or radiator cooling fan circuit (DTC P0480)? Go to corresponding 
DTC flow.Go to Step 2.
2 Low speed radiator cooling fan control circuit check
1) Connect scan tool to DLC with ignition switch turned 
OFF.
2) Start engine and select “DATA LIST” mode on scan tool.
3) Warm up engine until coolant temp. is 97.5  °C, 207.5  °F 
or higher and A/C switch turns OFF (if equipped with A/
C). (If engine coolant temp. dose not rise, check engine 
cooling system or ECT sensor.)
Is radiator cooling fan started at low speed when engine 
coolant temp. reached above temp.? Radiator cooling fan low 
speed control system is 
in good condition.
Perform from Step 2 to 
Step 8 in DTC P0480 
diag. flow. If OK, Go to 
Ste p 3.
3 Radiator cooling fan control check
1) Disconnect radiator cooling fan control relays No. 2, and 
No. 3 from individual circuit  fuse box No.1 with ignition 
switch turned OFF.
2) Run engine when ECT is over 97.5  °C, 207.5  °F.
3) Measure voltage between vehicle body ground and  “BLU/RED” wire terminal of disconnected radiator 
cooling fan motor connector.
Is voltage 10 – 14 V? Go to Step 4.
“BLU/RED” wire is open 
or high resistance 
circuit.
4 Check radiator cooling fan wire circuit check
1) Turn ignition switch to OFF position.
2) Measure resistance between “BLK” wire terminal of 
disconnected radiator coolin g fan motor connector and 
vehicle body ground.
Is resistance below 1 
Ω? Go to Step 5. “BLK” wire is open or 
high resistance circuit.
5 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.  
Page 264 of 1496
Downloaded from www.Manualslib.com manuals search engine 1A-214 Engine General Information and Diagnosis: 
Troubleshooting
WARNING! 
Keep hands, tools, and clothing away from engine cooling fan to help prevent personal injury. This fan 
is electric and can come on whether or not the engi ne is running. The fan can start automatically in 
response to the ECT sensor with the ig nition switch at the “ON” position.
 
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 Is there DTC(s) of ECT sensor circuit (DTC P0116 / P0117 / 
P0118) and/or radiator cooling fan circuit (DTC P0480)? Go to corresponding 
DTC flow.Go to Step 2.
2 Low speed radiator cooling fan control circuit check
1) Connect scan tool to DLC with ignition switch turned 
OFF.
2) Start engine and select “DATA LIST” mode on scan tool.
3) Warm up engine until coolant temp. is 97.5  °C, 207.5  °F 
or higher and A/C switch turns OFF (if equipped with A/
C). (If engine coolant temp. dose not rise, check engine 
cooling system or ECT sensor.)
Is radiator cooling fan started at low speed when engine 
coolant temp. reached above temp.? Go to Step 3.
Perform from Step 2 to 
Step 5 in “Radiator 
Cooling Fan Low Speed 
Control System Check”.
3 High speed radiator cooling fan control circuit check
1) Start engine and select “DATA LIST” mode on scan tool.
2) Warm up engine until coolant temp. is 102.5  °C, 216.5  °F 
or higher and A/C switch turns OFF (if equipped with A/
C). (If engine coolant temp. dose not rise, check engine 
cooling system or ECT sensor.)
Is radiator cooling fan started at high speed when engine 
coolant temp. reached above temp? Radiator cooling fan 
control system is in 
good condition.
Perform from Step 9 to 
Step 14 in DTC P0480 
diag. flow.
If OK, Go to Step 4.
4 Radiator cooling fan control No. 2 and No. 3 check
1) Run engine when ECT is over 102.5  °C, 216.5  °F.
2) Measure voltage between vehicle body ground and  “E23-48” terminal of ECM connector.
Is voltage lower than 1.5 V? Go to Step 5.
Faulty ECM.
5 Radiator cooling fan No. 2 wire circuit check
1) Remove radiator cooling fan control relay No.2 with 
ignition switch turned OFF.
2) Measure voltage between “GRY” wire terminal of  disconnected radiator cooling fan control relay No. 2 
connector and vehicle body ground.
Is voltage 10 – 14 V? Go to Step 6.
“GRY” wire is open or 
high resistance circuit.
6 Radiator cooling fan No. 2 wire circuit check
1) Disconnect connector from radiator cooling fan motor 
with ignition swit ch turned OFF.
2) Measure resistance between “BLU/BLK” wire terminal of  disconnected radiator cooling fan control relay No. 2 
connector and vehicle body ground.
Is resistance infinity? Go to Step 7.
“BLU/BLK” wire is 
shorted to ground 
circuit.  
Page 283 of 1496
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MAF and IAT Sensor On-Vehicle InspectionS7RS0B1306018
NOTE
Before performed this inspection, be sure to 
read the “Precautions of ECM Circuit 
Inspection in Section 1A”.
 
1) Disconnect negative (–) cable at battery.
2) Disconnect MAF and IAT sensor connector.
3) Connect voltmeter to “BLK/RED” wire terminal (2) of 
MAF and IAT sensor connector (1) disconnected and 
ground.
4) Turn ON ignition switch position and check that  voltage is battery voltage.
If not, check if wire harness is open or connection is 
poor.
5) Turn OFF ignition switch position and connect  connector to MAF and IAT sensor.
6) Remove ECM from its bracket referring to “ECM  Removal and Installation”.
7) Connect special tool between ECM and ECM  connector referring to “Inspection of ECM and Its 
Circuits in Section 1A”.
8) Turn ON ignition switch position and check MAF  signal voltage between “C37-26” terminal circuit and 
“C37-27” terminal circuit of special tool.
MAF signal voltage between “C37-26” terminal 
circuit and “C37-27” termi nal circuit of special 
tool
MAF signal voltage of MAF and IAT sensor with 
ignition switch turned ON: 0.5 – 1.0 V
9) Start engine and check that voltage is lower than 5 V  and it rises as engine speed increases.
MAF signal voltage between “C37-26” terminal 
circuit and “C37-27” termi nal circuit of special 
tool
MAF signal reference voltage of MAF and IAT 
sensor at specified Idle speed: 1.3 – 1.8 V 10) If check result is not as
 specified above, cause may 
lie in wire harness, connec tor connection, MAF and 
IAT sensor or ECM.
MAF and IAT Sensor Removal and InstallationS7RS0B1306019
CAUTION! 
• Do not disassemble MAF and IAT sensor.
• Do not expose MAF and IAT sensor to any  shock.
• Do not clean MAF and IAT sensor.
• If MAF and IAT sensor has been dropped, it  should be replaced.
• Do not blow compressed air by using air  gun or the like.
• Do not put finger or any other object into  MAF and IAT sensor. Malfunction may 
occur.
 
Removal
1) Disconnect negative (–) cable at battery.
2) Disconnect MAF and IAT sensor connector.
3) Remove air cleaner case (1).
4) Remove MAF and IAT sensor (2) from air cleaner  case.
Installation
Reverse removal procedure noting the followings.
• Tighten MAF and IAT sensor screws to specified  torque.
Tightening torque
MAF and IAT sensor screw (a):  1.5 N·m (0.15 kgf-
m, 1.1 lb-ft)
• Connect MAF and IAT sensor connector securely.
1. ECM
I3RB0A130009-01
“C37-27” “C37-26” 1
I4RS0A130009-01
1
2
I4RS0A130010-01
(a)
I4RS0A130011-01