Page 366 of 656
ENGINE AND EMISSION CONTROL SYSTEM (SEQUENTIAL MULTIPORT FUEL INJECTION FOR H27 ENGINE) 6E2-33
REMOVAL
1) Disconnect negative (–) cable at battery and coupler (1) from
MAF sensor (3).
2) Remove air cleaner outlet hose (2) from throttle body and
MAF sensor (3).
3) Remove MAF sensor from air cleaner case.
INSTALLATION
1) Check MAF sensor seal (1) for deterioration and damage.
2) Install MAF sensor to air cleaner case.
3) Install air cleaner outlet hose.
4) Connect MAF sensor coupler securely.
5) Connect negative (–) cable to battery.
CAUTION:
Don’t disassemble MAF sensor.
Do not expose MAF sensor to any shock.
Do not blow compressed air by using air gun or the
like.
Do not put finger or any other object into MAF sensor.
Malfunction may occur.
Page 367 of 656
6E2-34 ENGINE AND EMISSION CONTROL SYSTEM (SEQUENTIAL MULTIPORT FUEL INJECTION FOR H27 ENGINE)
Intake air temperature (IAT) sensor
REMOVAL
1) Disconnect negative (–) cable at battery.
2) Disconnect IAT sensor coupler.
3) Remove IAT sensor from air cleaner case.
INSPECTION
Immerse temperature sensing part of IAT sensor in water (or ice)
and measure resistance between sensor terminals while heating
water gradually.
If measured resistance doesn't show such characteristic as
shown in the figure, replace IAT sensor.
INSTALLATION
1) Clean mating surface of sensor and seal (2) on air cleaner
case.
2) Install IAT sensor (1) into seal.
3) Connect connector to IAT sensor securely.
Page 368 of 656

ENGINE AND EMISSION CONTROL SYSTEM (SEQUENTIAL MULTIPORT FUEL INJECTION FOR H27 ENGINE) 6E2-35
Throttle position sensor (TP sensor)
INSPECTION
1) Disconnect negative (–) cable at battery and coupler from TP
sensor (4).
2) Using ohmmeter, check resistance between terminals under
each condition given in table below.
If check result is not satisfactory, replace TP sensor.
TP sensor specification:
3) Connect TP sensor coupler securely.
4) Connect negative cable to battery.
REMOVAL
1) Disconnect negative (–) cable at battery.
2) Disconnect coupler from TP sensor.
3) Remove TP sensor from throttle body.
INSTALLATION
1) Install TP sensor (1) to throttle body (2).
Fit TP sensor (1) to throttle body (2) in such way that its
holes are a little away from TP sensor screw holes as shown
in the figure and turn TP sensor (1) clockwise so that those
holes align.
Tightening torque
TP sensor screw
(a) : 3.5 N·m (0.35 kg-m, 2.5 lb-ft)
2) Connect coupler to TP sensor securely.
3) Connect battery negative (–) cable to battery. TERMINALS RESISTANCE
Between 1 and
3 terminals4.0 – 6.0 kΩ
ΩΩ Ω
Between 1 and
2 terminals0.02 – 6.0 kΩ
ΩΩ Ω
varying linearly according to
throttle valve opening
1. Ground terminal
2. Output voltage terminal
3. Reference voltage terminal
Page 369 of 656
6E2-36 ENGINE AND EMISSION CONTROL SYSTEM (SEQUENTIAL MULTIPORT FUEL INJECTION FOR H27 ENGINE)
Engine coolant temperature sensor (ECT sensor)
REMOVAL
1) Disconnect negative (–) cable from battery.
2) Drain cooling system.
3) Disconnect coupler from ECT sensor (1).
4) Remove ECT sensor from water outlet cap (2).
INSPECTION
Immerse temperature sensing part of ECT sensor in water and
measure resistance between sensor terminals while heating
water gradually.
If measured resistance doesn’t shown such characteristic as
shown in the figure, replace ECT sensor.
INSTALLATION
Reverse removal procedure noting the followings.
•Clean mating surfaces of sensor and water outlet cap (1).
•Use new O-ring.
•Tighten ECT sensor to specified torque.
Tightening torque
ECT sensor (a) : 15 N·m (1.5 kg-m, 11.0 lb-ft)
•Connect coupler to sensor securely.
•Refill cooling system.
Page 370 of 656

ENGINE AND EMISSION CONTROL SYSTEM (SEQUENTIAL MULTIPORT FUEL INJECTION FOR H27 ENGINE) 6E2-37
Heated oxygen sensor (sensor 1)
REMOVAL
1) Disconnect negative (–) cable from battery.
2) Disconnect coupler of oxygen sensor (s).
3) Remove oxygen sensor (s) from exhaust manifold (s).
INSTALLATION
Reverse removal procedure noting the followings.
•Tighten oxygen sensor (s) to specified torque.
Tightening torque
Heated oxygen sensor 1
(a) : 45 N·m (4.5 kg-m, 32.5 lb-ft)
•Connect connector of oxygen sensor (s) and clamp wire har-
ness securely.
•After installing oxygen sensor (s), start engine and check
that no exhaust gas leakage exists.
INSPECTION
Inspect HO2S-1 and its circuit referring to “DTC P0130 or P0150
Diag. Flow Table” in Section 6-1. If malfunction is found, replace. WARNING:
To avoid danger of being burned, do not touch exhaust
system when system is hot. Oxygen sensor removal
should be performed when system is cool.
NOTE:
Be careful not to expose it to excessive shock.
1. Left (No.1) bank oxygen sensor (sensor 1)
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6E2-38 ENGINE AND EMISSION CONTROL SYSTEM (SEQUENTIAL MULTIPORT FUEL INJECTION FOR H27 ENGINE)
HEATER INSPECTION
1) Disconnect HO2S-1 or -2 coupler.
2) Using ohmmeter, measure resistance between terminals
“VB” and “GND” of HO2S coupler (1).
If found faulty, replace HO2S.
Resistance of HO2S heater:
11.7 – 14.3 Ω
ΩΩ Ω (at 20 °C (68 °F)) for HO2S-2
5.0 – 6.4 Ω
ΩΩ Ω (at 20 °C (68 °F)) for HO2S-1
3) Connect HO2S coupler securely.
Heated oxygen sensor (sensor 2)
REMOVAL
1) Disconnect negative (–) cable from battery.
2) Disconnect coupler (3) of oxygen sensor(s).
3) Remove oxygen sensor(s) (2) from exhaust manifold(s) (1).
INSTALLATION
Reverse removal procedure noting the followings.
•Tighten oxygen sensor(s) to specified torque.
Tightening torque
Heated oxygen sensor 2 (a) : 45 N·m (4.5 kg-m, 32.5 lb-ft)
•Connect connector of oxygen sensor(s) and clamp wire har-
ness securely.
•After installing oxygen sensor(s), start engine and check that
no exhaust gas leakage exists. NOTE:
Temperature of HO2S affects resistance value largely.
Make sure that HO2S heater is at correct temperature.
WARNING:
To avoid danger of being burned, do not touch exhaust
system when system is hot. Oxygen sensor removal
should be performed when system is cool.
NOTE:
Be careful not to expose it to excessive shock.
Page 372 of 656

ENGINE AND EMISSION CONTROL SYSTEM (SEQUENTIAL MULTIPORT FUEL INJECTION FOR H27 ENGINE) 6E2-39
HEATER INSPECTION
Refer to “HEATED OXYGEN SENSOR (SENSOR 1) HEATER
INSPECTION”
Vehicle speed sensor (VSS)
ON-VEHICLE INSPECTION
1) Hoist vehicle.
2) Release parking brake lever, set transmission in neutral and
transfer in “2H”.
3) Remove ECM (PCM) cover.
4) Connector voltmeter between VSS terminal C51-3-1 of ECM
(PCM) connector and body ground.
5) Turn ignition switch ON and turn rear right tire slowly with
rear left tire locked.
Voltmeter should indicate deflection between 0 – 1 V and 8 –
14 V a few times while tire (1) is turned one revolution.
If check result is not satisfactory, proceed to flow table of
“DTC P0500” in Section 6-1.
REMOVAL, INSPECTION AND INSTALLATION
Refer to “VSS Removal, Inspection or Installation” in Section 7D.
Manifold absolute pressure sensor
REMOVAL
1) Disconnect negative (–) cable at battery.
2) Disconnect connector from manifold absolute pressure sen-
sor.
3) Remove manifold absolute pressure sensor from intake
manifold.
[A]: Terminal arrangement of ECM (PCM) coupler
(viewed from harness side)
1. VSS
Page 373 of 656

6E2-40 ENGINE AND EMISSION CONTROL SYSTEM (SEQUENTIAL MULTIPORT FUEL INJECTION FOR H27 ENGINE)
INSPECTION
1) Check sensor O-ring (1) for damage and deterioration.
Replace as necessary.
2) Arrange 3 new 1.5 V batteries (2) in series and connect its
positive terminal to “Vin” terminal of MAP sensor (1) and
negative terminal to “Ground” terminal. Then check voltage
between “Vout” and “Ground”.
Also, check if voltage reduces when vacuum is slowly
applied up to 400 mmHg by using vacuum pump (3).
If check result is not satisfactory, replace manifold absolute
pressure sensor.
MAP sensor output voltage (Vin voltage 4.5 – 5.5 V, ambi-
ent temp. 20 – 30°C (68 – 86°F))
CAUTION:
As connection to wrong terminal will cause damage to
manifold absolute pressure sensor, make absolutely sure
to connect properly as shown in the figure.
ALTITUDE
(Reference)BAROMETRIC
PRESSUREOUTPUT
VOLTAGE
(ft) (m) (mmHg) (kPa) (V)
0
–
20000
–
610760
–
707100 – 94 3.3 – 4.3
2001
–
5000611
–
1524Under 707
over 63494 – 85 3.0 – 4.1
5001
–
80001525
–
2438Under 634
over 56785 – 76 2.7 – 3.7
8001
–
100002439
–
3048Under 567
over 52676 – 70 2.5 – 3.3