Wheel Sensor
The wheel sensors are the magnetic contactless type. As the gear pulser teeth rotate past the wheel sensor's magnetic
coil, AC current is generated. The AC frequency changes in accordance with the wheel speed. The ABS control unit detects
the wheel sensor signal frequency and thereby detects the wheel speed
at LOW SPEED
wheel Sp€od and Modulatot Control
VEHICLE SPEED
VEHICLE SPEED
WHEEL SPEED
PRESSU
OUTLETVALVE ON
OFF
INLETVALVE ON
OFF
MOTOR
ON
OFF
When the wheel speed drops sharply below the vehicle speed, the outlet valve opens momentarily to reduce the caliper
fluid pressure. The pump motor starts at this time. As the wheel speed is restored. the inlet valve opens momentarily to
increase the caliDer fluid oressure.
F
GEAR PULSER
19-31
www.emanualpro.com
Troubleshooting
Symptom Ghart
For electrical malfunctions which are indicated by the self-diagnostic system, reter to selt-diagnosjs function (see next
page).
Note these items before troubleshooting a symptom.
. Check the engine coolant level, and allow the engine to warm up before troubleshooting.
. Anv abnormality must be corrected before continuing the test.
. Because of the precise measurements needed, use a digital multimeter with an output of 1 mA or less at the 20 kO
range when testing.
. Before performing any troubleshooting procedures check:
- Fuses No. 47 17.5 AJ, No. 55 (40 A), No. 56 (20 A), No. 57 (20 A) in the under-hood fuse/relay box, and No. 17 {7.5 A) in
the under-dash fuse/relay box.._ Grounds No. G101, G201, G202, G401, G4O2
- Cleanliness and tightness of all connectors
SymptomSse pags
Mode control motor does not run, or one or more modes are inoperative.
Recirculation control door does not change between Fresh and Recirculate.22-24
Radiator fan does not run at all (but condenser fan runs with the AVC on).
Condenser fan does not run at all {but radiator fan runs with the Ay'C on).22-29
Both fans (radiator and condenser) do not run for engine cooling. but they both run with the A,/C
on.
Both fans do not run with the Ay'C on22-33
Compressor clutch does not engage.22-34
AJC svstem does not come on (both fans and compressor).22-37
Both heater and A/C do not work,22-39
22-10
www.emanualpro.com
Evaporator Temperature
SensorPower Transistor
Test
Dip the sensor in ice water, and measure the resistance
with a digital multimeter. Then pour hot water on the
sensor, and check lor change in resistance.
Compare the resistance reading between the No. | 8nd
No. 2 terminals of the evaporator temperature sensor
with the specifications shown in the following graph;
resistance should be within the specifications.
EVAPOBATOR TEMPERATURE SENSOB
Terminal side ol male terminals
4
RESISTANCEko
t0
50 68 86.F10 20 30'c
22-44
12V 1.2-3.1W
No. 2 ILT GRN/BLK)
No. I IBLU/BLK)
Test
1.Disconnect the 3P connector from the oower tran-
st$or.
Carefully release the lock tab on the No. 2 terminal in
the 3P connector, then remove the terminal and insu-
late it from body ground.
Connect a 1.2 - 3.4 W bulb between the No, 1 and
the No,2 cavity on the 3P connectol
Reconnect the 3P connector to the power transistor.
Turn the ignition switch ON (ll). and check that the
blower motor runs.
a lf the blower motor runs at half soeed the oower
transistor is OK, replace the heater control panel.
. lf ths blower motor does not run at half soeed,
reDlaca the Dower transistor.
www.emanualpro.com
