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Wiring DiagramNBEC0056
MEC942C
DTC P0100 MASS AIR FLOW SENSOR (MAFS)
Wiring Diagram
EC-154
Page 690 of 2395
Diagnostic ProcedureNBEC0057
1 INSPECTION START
Which malfunction (A, B, C, D or E) is duplicated?
MTBL0373
Type I or Type II
Type I©GO TO 3.
Type II©GO TO 2.
2 CHECK INTAKE SYSTEM
Check the following for connection.
IAir duct
IVacuum hoses
IIntake air passage between air duct to intake manifold collector
OK or NG
OK©GO TO 3.
NG©Reconnect the parts.
3 RETIGHTEN GROUND SCREWS
1. Turn ignition switch ªOFFº.
2. Loosen and retighten engine ground screws.
SEF959Y
©GO TO 4.
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DTC P0100 MASS AIR FLOW SENSOR (MAFS)
Diagnostic Procedure
EC-155
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4 CHECK MAFS POWER SUPPLY CIRCUIT
1. Disconnect mass air flow sensor (MAFS) harness connector.
SEF960Y
2. Turn ignition switch ªONº.
3. Check voltage between MAFS terminals 2, 4 and ground with CONSULT-II or tester.
SEF297X
OK or NG
OK©GO TO 6.
NG©GO TO 5.
5 DETECT MALFUNCTIONING PART
Check the following.
IHarness for open or short between ECM relay and mass air flow sensor
IHarness for open or short between mass air flow sensor and ECM
©Repair harness or connectors.
6 CHECK MAFS GROUND CIRCUIT FOR OPEN AND SHORT
1. Turn ignition switch ªOFFº.
2. Disconnect ECM harness connector.
3. Check harness continuity between MAFS terminal 3 and ECM terminal 73.
Refer to Wiring Diagram.
Continuity should exist.
4. Also check harness for short to power.
OK or NG
OK©GO TO 7.
NG©Repair open circuit or short to power in harness or connectors.
DTC P0100 MASS AIR FLOW SENSOR (MAFS)
Diagnostic Procedure (Cont'd)
EC-156
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7 CHECK MAFS INPUT SIGNAL CIRCUIT FOR OPEN AND SHORT
1. Check harness continuity between MAFS terminal 1 and ECM terminal 61.
Refer to Wiring Diagram.
Continuity should exist.
2. Also check harness for short to ground and short to power.
OK or NG
OK©GO TO 8.
NG©Repair open circuit or short to ground or short to power in harness or connectors.
8 CHECK MASS AIR FLOW SENSOR
1. Reconnect harness connectors disconnected.
2. Start engine and warm it up to normal operating temperature.
3. Check voltage between ECM terminal 61 (Mass air flow sensor signal) and ground.
SEF298X
4. If the voltage is out of specification, disconnect MAFS harness connector and connect it again.
Then repeat above check.
OK or NG
OK©GO TO 9.
NG©Replace mass air flow sensor.
9 CHECK INTERMITTENT INCIDENT
Refer to ªTROUBLE DIAGNOSIS FOR INTERMITTENT INCIDENTº, EC-140.
©INSPECTION END
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DTC P0100 MASS AIR FLOW SENSOR (MAFS)
Diagnostic Procedure (Cont'd)
EC-157
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SEF052V
SEF946SB
Component DescriptionNBEC0725The absolute pressure sensor detects ambient barometric pressure
and sends the voltage signal to the ECM. As the pressure
increases, the voltage rises.
ECM Terminals and Reference ValueNBEC0726Specification data are reference values and are measured between each terminal and ground.
CAUTION:
Do not use ECM ground terminals when measuring input/output voltage. Doing so may result in dam-
age to the ECM's transistor. Use a ground other than ECM terminals, such as the ground.
TERMI-
NAL
NO.WIRE
COLORITEM CONDITION DATA (DC Voltage)
80 L/RAbsolute pressure sen-
sor[Ignition switch ªONº]Approximately 4.4V
111 P/B Sensors' power supply[Ignition switch ªONº]Approximately 5V
58 B/P Sensors' ground[Engine is running]
IWarm-up condition
IIdle speedApproximately 0V
On Board Diagnosis LogicNBEC0727Malfunction is detected when an excessively low or high voltage
from the sensor is sent to ECM.
DTC P0105 ABSOLUTE PRESSURE SENSOR
Component Description
EC-158
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Possible CauseNBEC0728IHarness or connectors
(Absolute pressure sensor circuit is open or shorted.)
IAbsolute pressure sensor
DTC Confirmation ProcedureNBEC0729NOTE:
If ªDTC Confirmation Procedureº has been previously conducted,
always turn ignition switch ªOFFº and wait at least 10 seconds
before conducting the next test.
SEF058Y
WITH CONSULT-IINBEC0729S011) Turn ignition switch ªONº.
2) Select ªDATA MONITORº mode with CONSULT-II.
3) Wait at least 10 seconds.
4) If 1st trip DTC is detected, go to ªDiagnostic Procedureº,
EC-161.
WITH GSTNBEC0729S02Follow the procedure ªWITH CONSULT-IIº above.
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DTC P0105 ABSOLUTE PRESSURE SENSOR
Possible Cause
EC-159
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Wiring Diagram=NBEC0730
MEC943C
DTC P0105 ABSOLUTE PRESSURE SENSOR
Wiring Diagram
EC-160
Page 696 of 2395
Diagnostic ProcedureNBEC0731
1 RETIGHTEN GROUND SCREWS
1. Turn ignition switch ªOFFº.
2. Loosen and retighten engine ground screws.
SEF959Y
©GO TO 2.
2 CHECK ABSOLUTE PRESSURE SENSOR CONNECTOR FOR WATER
1. Disconnect absolute pressure sensor harness connector.
SEF961Y
2. Check sensor harness connector for water.
Water should not exist.
OK or NG
OK©GO TO 3.
NG©Repair or replace harness connector.
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DTC P0105 ABSOLUTE PRESSURE SENSOR
Diagnostic Procedure
EC-161