MAF SUZUKI SWIFT 2004 2.G Service Owner's Manual

Downloaded from www.Manualslib.com manuals search engine Engine General Information and Diagnosis: 1A-61
DTC P0102: Mass or Volume Air Flow Circuit Low InputS7RS0B1104018
Wiring Diagram
Refer to “DTC P0101: Mass or Volume Air Flow Circuit Range / Performance”.
DTC Detecting Condition and Trouble Area
DTC Confirmation Procedure1) With ignition switch turned OFF, connect scan tool.
2) Turn ON ignition switch and clear DTC using scan tool.
3) Start engine and run it for 10 sec.
4) Check DTC.
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.

10 MAF sensor signal circuit check
1) Measure resistance between “GRN/BLK” wire terminal
of MAF and IAT sensor connector and “C37-26” terminal
of ECM connector.
Is resistance below 3
Ω? Faulty MAF and IAT
sensor.
“GRN/BLK” wire is open
or high resistance
circuit.
11 Is DTC P2135 detected? Go to “DTC P2135:
Throttle / Pedal Position
Sensor / Switch “A”/“B”
(Main / Sub) Voltage
Correlation”.Go to Step 12.
12 Is DTC P0106 displayed? Go to “DTC P0106:
Manifold Absolute
Pressure / Barometric
Pressure Circuit Range
/ Performance”.Substitute a known-
good ECM and recheck.
Step
Action YesNo
DTC detecting condition Trouble area
MAF sensor output voltage is less than 0.15 V for 0.5
seconds continuously
(1 driving cycle detection logic) • Open or short in MAF sensor circuit
• MAF sensor
•ECM
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 MAF sensor and its circuit check
1) Connect scan tool to DLC with ignition switch turned
OFF.
2) Start engine and check MAF value displayed on scan tool. (Refer to “Scan Tool Data” for normal value.)
Is normal value indicated? Intermittent trouble.
Check for intermittent
referring to “Intermittent
and Poor Connection
Inspection in Section
00”.
Go to Step 3.

Downloaded from www.Manualslib.com manuals search engine 1A-62 Engine General Information and Diagnosis:
3MAF sensor power supply voltage check
1) Disconnect connector from MAF and IAT sensor with
ignition switch turned OFF.
2) Turn ON ignition switch, measure voltage between engine ground and “BLK/RED” wire terminal of MAF and
IAT sensor connector.
Is voltage 10 – 14 V? Go to Step 4. “BLK/RED” wire is open
circuit.
4 MAF sensor ground circuit check
1) Turn OFF ignition switch, measure resistance between
“GRY” wire terminal of MAF and IAT sensor connector
and engine ground.
Is resistance below 5
Ω? Go to Step 6.
Go to Step 5.
5 Ground circuit check
1) Remove ECM from its br acket with ECM connectors
connected.
2) Measure resistance between “C37-27” terminal of ECM connector and engine ground.
Is resistance below 5
Ω? “GRY” wire is open or
high resistance circuit.
ECM grounds “E23-31”,
“C37-58”, “C37-15” and/
or “C37-30” circuit is
open or high resistance.
If wires are OK,
substitute a known-
good ECM and recheck.
6 MAF sensor signal circuit check
1) Disconnect connectors from ECM with ignition switch
turned OFF.
2) Measure voltage between “GRN/BLK” wire terminal of MAF and IAT sensor connector and engine ground with
ignition switch turned ON.
Is voltage 0 V? Go to Step 7. “GRN/BLK” wire is
shorted to other circuit.
7 MAF sensor signal circuit check
1) Measure resistance between “GRN/BLK” wire terminal
of MAF and IAT sensor connector and engine ground
with ignition swit ch turned OFF.
Is resistance infinity? Go to Step 8.
“GRN/BLK” wire is
shorted to ground
circuit.
8 MAF sensor signal circuit check
1) Measure resistance between “GRN/BLK” wire terminal
of MAF and IAT sensor connector and “C37-26” terminal
of ECM connector.
Is resistance below 3
Ω? Go to Step 9.
“GRN/BLK” wire is open
or high resistance
circuit.
9 MAF sensor output signal check
1) Connect connectors to MAF and IAT sensor and ECM
with ignition swit ch turned OFF.
2) Measure voltage between “C37-26” and “C37-27” terminals of ECM connector referring to “MAF and IAT
Sensor On-Vehicle Inspection in Section 1C”.
Is each value within specified range? Substitute a known-
good ECM and recheck.
Faulty MAF and IAT
sensor.
Step
Action YesNo

Downloaded from www.Manualslib.com manuals search engine Engine General Information and Diagnosis: 1A-63
DTC P0103: Mass or Volume Air Flow Circuit High InputS7RS0B1104019
Wiring Diagram
Refer to “DTC P0101: Mass or Volume Air Flow Circuit Range / Performance”.
DTC Detecting Condition and Trouble Area
DTC Confirmation Procedure1) With ignition switch turned OFF, connect scan tool.
2) Turn ON ignition switch and clear DTC using scan tool.
3) Start engine and run it for 10 sec.
4) Check DTC.
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.

DTC detecting condition Trouble area
MAF sensor output voltage is higher than 4.85 V for 0.5 seconds
continuously.
(1 driving cycle detection logic) • Open or short in MAF sensor circuit
• MAF sensor
•ECM
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 MAF sensor and its circuit check
1) Connect scan tool to DLC with ignition switch turned
OFF.
2) Start engine and check MAF value displayed on scan tool. (Refer to “Scan Tool Data” for normal value.)
Is normal value indicated? Intermittent trouble.
Check for intermittent
referring to “Intermittent
and Poor Connection
Inspection in Section
00”.
Go to Step 3.
3 MAF sensor power supply voltage check
1) Disconnect connector from MAF and IAT sensor with
ignition switch tuned OFF.
2) Turn ON ignition switch, measure voltage between engine ground and “BLK/RED” wire terminal of MAF and
IAT sensor connector.
Is voltage 10 – 14 V? Go to Step 4.
“BLK/RED” wire is open
circuit.
4 MAF sensor ground circuit check
1) Turn OFF ignition switch, measure resistance between
“GRY” wire terminal of MAF and IAT sensor connector
and engine ground.
Is resistance below 5
Ω? Go to Step 6. Go to Step 5.
5 Ground circuit check
1) Remove ECM from its br acket with ECM connectors
connected.
2) Measure resistance between “C37-27” terminal of ECM connector and engine ground.
Is resistance below 5
Ω? “GRY” wire is open or
high resistance circuit.
ECM grounds “E23-31”,
“C37-58”, “C37-15” and/
or “C37-30” circuit are
open or high resistance.
If wires are OK,
substitute a known-
good ECM and recheck.

Downloaded from www.Manualslib.com manuals search engine 1A-64 Engine General Information and Diagnosis:
DTC P0106: Manifold Absolute Pressure / Barometric Pressure Circuit Range / PerformanceS7RS0B1104020
Wiring Diagram
DTC Detecting Condition and Trouble Area6
MAF sensor signal circuit check
1) Disconnect connectors from ECM with ignition switch
turned OFF.
2) Measure voltage between “GRY/BLK” wire terminal of MAF and IAT sensor connector and engine ground.
Is voltage 0 V? Go to Step 7. “GRY/BLK” wire is
shorted to other circuit.
7 MAF sensor output signal check
1) Connect connector to MAF and IAT sensor and ECM
with ignition swit ch turned OFF.
2) Measure voltage between “C37-26” and “C37-27” terminal of ECM connector referring to “MAF and IAT
Sensor On-Vehicle Inspection in Section 1C”.
Is each value within specified range? Substitute a known-
good ECM and recheck.
Faulty MAF and IAT
sensor.
Step Action Yes No
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
4
C37-58
C37-15 C37-30
BLK/ORN
BLKBLKE23-31 BLK
1
2
3
GRY/REDGRY/RED
5V
5VC37-14
C37-53
C37-55
RED/BLK
ORNORN
I6RS0C110008-02
1. Manifold absolute pressure sensor
3. To other sensors
2. To A/C refrigerant pressure sensor (if equipped with A/C) 4. ECM
DTC detecting condition Trouble area
• Difference between Max. manifold absolute pressure value and Min. manifold pressure value is less than 1.3
kPa (0.19 psi) when engine running at idle speed.
• Difference between barometric pressure value and manifold pressure value is less than 33.3 kPa (4.83 psi)
for 5 sec. at 2000 r/mini. or more.
(2 driving cycle detection logic) • Manifold absolute pressure sensor
• Manifold absolute pressure sensor vacuum passage
• Air intake system
•ECM

Downloaded from www.Manualslib.com manuals search engine Engine General Information and Diagnosis: 1A-69
DTC P0111: Intake Air Temperature Sensor 1 Circuit Range / PerformanceS7RS0B1104023
Wiring Diagram6
Ground circuit check
1) Measure resistance between “C37-55” terminal of ECM
connector and vehicle body ground.
Is resistance below 5
Ω? “ORN” wire is open or
high resistance circuit.
ECM grounds “E23-31”,
“C37-58”, “C37-15” and/
or “C37-30” circuit are
open or high resistance.
If wires are OK,
substitute a known-
good ECM and recheck.
7 MAP sensor signal circuit check
1) Turn ON ignition switch.
2) Measure voltage between “RED/BLK” wire terminal of
MAP sensor connector and engine ground.
Is voltage 4 – 6 V? Go to Step 9. Go to Step 8.
8 MAP sensor signal circuit check
1) Disconnect connectors from ECM with ignition switch
turned OFF.
2) Measure resistance between “RED/BLK” wire terminal of MAP sensor connector and “C37-53” terminal of ECM
connector.
Is resistance below 2
Ω? “RED/BLK” wire is
shorted to power supply
circuit.
“RED/BLK” wire is open
or high resistance
circuit.
9 MAP sensor output signal check
1) Check MAP sensor acco rding to “MAP Sensor
Inspection in Section 1C”.
Is it in good condition? Substitute a known-
good ECM and recheck.
Faulty MAP sensor.
Step Action Yes No
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
5V
2
BLK/YEL
GRY/BLU
GRY
ORN
1
GRN/BLK
C37-25
C37-55 3 4ORN
C37-26
C37-27
BLK/RED
I4RS0B110018-01
1. MAF and IAT sensor
3. To other sensors
2. ECM 4. From main relay

Downloaded from www.Manualslib.com manuals search engine 1A-70 Engine General Information and Diagnosis:
DTC Detecting Condition and Trouble Area
DTC Confirmation Procedure
NOTE
Check to make sure that following conditions are satisfied when using this “DTC Confirmation
Procedure”.
• Intake air temperature at engine start: –10 °C (14 ° F) to 80 °C (176 °F)
• Intake air temperature: –10 °C (14 °F) to 70 °C (158 °F)
• Engine coolant temperature at engine start: less than 30 °C (86 °F)
• Engine coolant temperature: 70 °C (158 °F) to 150 °C (302 °F)
• Altitude (barometric pressure): 2400 m, 8000 ft or less (560 mmHg, 75 kPa or more)

1) With ignition switch turned OFF, connect scan tool.
2) Turn ON ignition switch, clear DTC using scan tool.
3) Start engine and warm up to normal operating temperature. (ECT approx. 90 – 95 °C, 194 – 203 °F)
4) Run engine at idle speed for 10 min. or more.
5) Check DTC and pending DTC.
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.

DTC detecting condition Trouble area
Difference of maximum IAT minus minimum IAT is less than 0.3 °C
(32.5 °F) while ECT is over 70 °C (158 °F) after 10 min from cold
engine start (ECT is lower than 30 °C (86 °F) at engine start).
(2 driving cycle detection logic) • High resistance circuit
• MAF and IAT sensor
•ECM
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 IAT sensor and its circuit check
1) Connect scan tool to DLC with ignition switch turned
OFF.
2) Turn ignition switch to ON position.
3) Check intake air temp. displayed on scan tool.
Is –40
°C (–40 °F) or 119 °C (246 °F) indicated? Go to Step 3. Intermittent trouble.
Check for intermittent
referring to “Intermittent
and Poor Connection
Inspection in Section
00”.

Downloaded from www.Manualslib.com manuals search engine Engine General Information and Diagnosis: 1A-71
3Wire harness check
1) Disconnect MAF and IAT sensor connector (1) with
ignition switch turned OFF.
2) Check for proper connection to MAF and IAT sensor connector (1) at “BLK/YEL” wire terminal.
3) If OK, then with ignition switch turned ON, measure voltage between “BLK/YEL” wire terminal of MAF and
IAT sensor connector and vehicle body ground.
Is measured voltage applied to “BLK/YEL” wire terminal
about 4 – 6 V? Go to Step 8. Go to Step 4.
4 ECM voltage check
1) Turn OFF ignition switch.
2) Remove ECM from its br acket with ECM connectors
connected.
3) Check for proper connection of ECM connector at “C37- 25” terminal.
4) If OK, then turn ON igniti on switch, measure voltage
between “C37-25” terminal of ECM connector and
vehicle body ground.
Is voltage about 4 – 6 V at terminal? “BLK/YEL” wire is open
circuit.
If wire and connection
are OK, go to Step 5.
Go to Step 5.
5 Wire circuit check
1) Disconnect connectors from ECM with ignition switch
turned OFF.
2) Measure resistance between “BLK/YEL” wire terminal of MAF and IAT sensor connector and vehicle body
ground.
Is resistance infinity? Go to Step 6. “BLK/YEL” wire is
shorted to ground or
other circuit.
If wire is OK, substitute
a known-good ECM and
recheck.
6 Wire circuit check
1) Turn ignition switch to ON position.
2) Measure voltage between “BLK/YEL” wire terminal of
MAF and IAT sensor connector and vehicle body
ground.
Is voltage about 0 V? Go to Step 7. “BLK/YEL” wire shorted
to other circuit.
If wire is OK, substitute
a known-good ECM and
recheck.
7 Wire circuit check
1) Measure resistance between “C37-25” terminal of ECM
connector and “BLK/YEL” wire terminal of MAF and IAT
sensor connector with ignition switch turned OFF.
Is resistance below 3
Ω? Go to Step 8.
“BLK/YEL” wire is high
resistance circuit.
Step
Action YesNo
I4RS0B110020-01

Downloaded from www.Manualslib.com manuals search engine 1A-72 Engine General Information and Diagnosis:
DTC P0112: Intake Air Temperature Sensor 1 Circuit LowS7RS0B1104024
Wiring Diagram
Refer to “DTC P0111: Intake Air Temperature Sensor 1 Circuit Range / Performance”.
DTC Detecting Condition and Trouble Area
DTC Confirmation Procedure1) With ignition switch turned OFF, connect scan tool.
2) Turn ON ignition switch and clear DTC using scan tool.
3) Start engine and run it for 10 sec.
4) Check DTC.
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.

8 Ground circuit check
1) Connect connectors to ECM.
2) Check for proper connection of MAF and IAT sensor
connector at “GRY/BLU” wire terminal.
3) Measure resistance between “GRY/BLU” wire terminal of MAF and IAT sensor connector and vehicle body
ground with ignition switch turned OFF.
Is resistance below 5
Ω? Go to Step 10. Go to Step 9.
9 Ground circuit check
1) Remove ECM from its br acket with ECM connectors
connected.
2) Measure resistance between “C37-55” terminal of ECM connector and vehicle body ground.
Is resistance below 3
Ω? “GRY/BLU” wire and/or
“ORN” wire is open or
high resistance circuit.
Poor “C37-55”
connection.
Faulty ECM ground
circuit.
If circuit is OK,
substitute a known-
good ECM and recheck.
10 IAT sensor check
1) Check IAT sensor according to “MAF and IAT Sensor
Inspection in Section 1C”.
Is it in good condition? Substitute a known-
good ECM and recheck.
Replace MAF and IAT
sensor.
Step Action Yes No
DTC detecting condition
Trouble area
IAT sensor output voltage is less than 0.15 V for 0.5 seconds
continuously.
(High intake air temperature (low voltage/low resistance))
(1 driving cycle detection logic) • IAT sensor circuit
• IAT sensor
•ECM

Downloaded from www.Manualslib.com manuals search engine Engine General Information and Diagnosis: 1A-73
StepAction YesNo
1 Was “Engine and Emission Control System Check”
performed? Go to Step 2.
Go to “Engine and
Emission Control
System Check”.
2 IAT sensor and its circuit check
1) Connect scan tool to DLC with ignition switch turned
OFF.
2) Turn ON ignition switch.
3) Check intake air temp. displayed on scan tool.
Is 119
°C (246 °F) indicated? Go to Step 3. Intermittent trouble.
Check for intermittent
referring to “Intermittent
and Poor Connection
Inspection in Section
00”.
3 ECM voltage check
1) Disconnect connector from MAF and IAT sensor with
ignition switch turned OFF.
2) Check for proper connection to MAF and IAT sensor at “BLK/YEL” and “GRY/BLU” wire terminals.
3) If OK, then turn ON igniti on switch, measure voltage
between “BLK/YEL” wire terminal of MAF and IAT
sensor connector (1) and vehicle body ground.
Is voltage about 4 – 6 V? Go to Step 6. Go to Step 4.
4 IAT short circuit check
1) Disconnect connectors from ECM with ignition switch
turned OFF.
2) Measure resistance between “BLK/YEL” wire terminal of MAF and IAT sensor connector and vehicle body
ground.
Is resistance infinity? Go to Step 5. “BLK/YEL” wire is
shorted to ground
circuit.
If wire is OK, substitute
a known-good ECM and
recheck.
5 IAT short circuit check
1) Turn ON ignition switch.
2) Measure voltage between “BLK/YEL” wire terminal of
MAF and IAT sensor connector and vehicle body
ground.
Is voltage about 0 V? Go to Step 6. “BLK/YEL” wire is
shorted to other circuit.
If wire is OK, substitute
a known-good ECM and
recheck.
6 IAT sensor for performance check
1) Check IAT sensor according to “MAF and IAT Sensor
Inspection in Section 1C”.
Is it in good condition? Substitute a known-
good ECM and recheck.
Replace MAF and IAT
sensor.
I4RS0B110020-01

Downloaded from www.Manualslib.com manuals search engine Engine General Information and Diagnosis: 1A-75
3IAT sensor voltage check
1) Disconnect connector from MAF and IAT sensor with
ignition switch turned OFF.
2) Check for proper connection to MAF and IAT sensor at “BLK/YEL” and “GRY/BLU” wire terminals.
3) If OK, then turn ON igniti on switch, measure voltage
between “BLK/YEL” wire terminal of MAF and IAT
sensor connector (1) and vehicle body ground.
Is voltage about 4 – 6 V? Go to Step 7. Go to Step 4.
4 ECM voltage check
1) Turn OFF ignition switch.
2) Remove ECM from its br acket with ECM connectors
connected.
3) Check for proper connection of ECM connector at “C37- 25” terminal.
4) If OK, then turn ON igniti on switch, measure voltage
between “C37-25” terminal of ECM connector and
vehicle body ground.
Is voltage about 4 – 6 V? “BLK/YEL” wire is open
circuit. If wire and
connection are OK, go
to Step 5.
Go to Step 5.
5 Wire circuit check
1) Disconnect connectors from ECM with ignition switch
turned OFF.
2) Turn ON ignition switch.
3) Measure voltage between “BLK/YEL” wire terminal of MAF and IAT sensor connector and vehicle body
ground.
Is voltage about 0 V? Go to Step 6.
“BLK/YEL” wire is
shorted to other circuit.
If wire is OK, substitute
a known-good ECM and
recheck.
6 Wire circuit check
1) Measure resistance between “C37-25” terminal of ECM
connector and “BLK/YEL” wire terminal of MAF and IAT
sensor connector with ignition switch turned OFF.
Is resistance below 5
Ω? Go to Step 7. “BLK/YEL” wire is high
resistance circuit.
7 Ground circuit check
1) Connect connectors to ECM.
2) Measure resistance between “GRY/BLU” wire terminal
of MAF and IAT sensor connector and vehicle body
ground with ignition switch turned OFF.
Is resistance below 5
Ω? Go to Step 9. Go to Step 8.
Step Action Yes No
I4RS0B110020-01