Mazda B-Series 1997 Workshop Manual page 375

OUTLINE
Turbine shafi speed
(TSS) sensor
COMPONENT
Throttle position (TP)
sensor
Torque converter
clutch (TCC) solenoid
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Transmission control
indicator lamp (TCIL)
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Vehicle speed sensor
(VSS)
Detects speed coming in.
Outputs voltage signal to PCM.
PCM controls the following:
1.
Shiftltorque converter clutch scheduling
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Detects speed going out.
Outputs frequency signal to PCM.
)
PCM controls operation as follows:
;
1. Fuel injection
:
2. Ignition timing
i
3. Shiftltorque converter clutch scheduling
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4. EPC
FUNCTION
Detects throttle plate opening angle and
outputs analog voltage signal to PCM.
PCM determines four operating conditions:
1. Closed throttle (idleldeceleration)
2. Part throttle (cruise/acceleration)
3. Wide open throttle (maximum
acceleration)
4.
Throttle angle rate
Controls application, modulation and release
of torque converter clutch.
PCM outputs driver signal to solenoid.
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PCM controls lamp ONIOFF function
depending on TCS ONIOFF conditions.
If transmission-related device is
malfunctioning, lamp starts to flash.
Wide open throttle
A/C cut-off (WAC)
relay
REMARK
Uses a rotary potentiometer that is rotated by
throttle shaft. As throttle plate is opened or closed,
output signal changes linearly.
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TCC solenoid is normally open and pulse width
modulated solenoid.
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Transmission control Outputs keypower whenever TCS is cycled
switch (TCS) to PCM.
Disengages A/C clutch during the following
conditions:
Engine cranking
Engine overheated
Wide open throttle
Uses a momentary contact switch.
Uses a magnetic pick-up sensor.
Sensor is mounted on center support of
transmission.
Transmission fluid
errnistor devices.
temperature (TFT) nce changes with temperature:
sensor
Resistance increases as temperature
PCM controls the following:
1. Shift scheduling for cold fluid
2. Inhibits TCC operation
ries with sensor determines voltage
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p p
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Digital transmissio cts transmission range. Uses a ratiometric sensor with six resistors in
range sensor
PCM controls the following: neutral sense for 4x4 control.
TR sensor is adjustable.
2. Shift scheduling
1
Uses a variable reluctance sensor. Sensor
(
generates a sine wave type waveform with a
I
frequency.
High frequency as vehicle velocity increases.
:
Low frequency as vehicle velocity decreases.
Installed in transmission (4x2) or transfer case
(4x4).
If EPC solenoid is shorted to ground, PCM outputs
DTC for VSS. Diagnose EPC solenoid first, then
check VSS.
WAC relay is normally closed relay.
When A/C switch is turned on, and A/C cycling
switch and N C pressure switch are closed,
voltage is supplied to relay and PCM. PCM will
then verify that A/C clutch operation is desirable.
PCM controls as follows:
If desirable:
Adjust idle speed and unground
relay
If not desirable: Ground relay.
7BUOFT-009