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Engine distributors DSG-423 User Manual

Engine distributors DSG-423
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DSG-423 ENGINE CONTROLS
08-7
Temperature Manifold Absolute Pressure (TMAP)
Sensor
The Temperature Manifold Absolute Pressure (TMAP)
Sensor responds to changes in intake manifold
pressure (vacuum). The TMAP sensor signal voltage to
the GCP varies from below 2 volts at idle (high vacuum)
to above 4 volts with the ignition ON, engine not running
or at wide-open throttle (low vacuum).
The TMAP sensor consists of a pressure sensing
element (capacitor) and signal conditioning electronics.
The capacitor has a vacuum/pressure reference which
results in one surface (diaphragm) of the capacitor
being partially deflected. Further changes in pressure
produce corresponding changes in the deflection of the
diaphragm and therefore a change in capacitance. This
capacitance change is converted to a frequency by the
conditioning electronics.
The TMAP sensor is used to determine the following:
Engine vacuum level for engine control purposes.
Barometric pressure (BARO).
Specifications:
Range of Measurement: 1.7 - 15.2 psi.
Measurement Accuracy: ± 0.2 psi
Sensor Response Time: 3-15 msec.
Resolution: 0.02 psi
Present design: Silicon Capacitive Absolute Pressure
(SCAP) sensor with a maximum operating temperature
of 100°C. The output is a 50% duty cycle wave form
whose frequency is proportional to the pressure input.
Throttle Position (TP) Sensor / Electronic Actuator
The Throttle Position (TP) Sensor is a dual track rotary
potentiometer that uses a variable resistive element
which is packaged inside a plastic housing. The
resistive element varies linearly and is directly
proportional to the throttle plate angle. The GCP applies
reference voltage and ground to the sensor and
monitors the sensor’s ratio metric output voltage to
determine precise throttle position. The electronic
actuator has two TP outputs that the GCP monitors.
The Electronic Actuator consists of a throttle body, an
electronically-actuated throttle plate, and a built-in
throttle position (TP) Sensor.
The Electronic Actuator also acts as an idle air control
(IAC) valve. Changes in engine load are detected by the
GCP by comparing manifold absolute pressure (TMAP)
with throttle position. When the GCP detects a change
in engine load, it can adjust idle speed by changing the
PWM signal to the actuator.
As the throttle valve opens, the output increases so that
at wide open throttle (WOT), the output voltage should
be above 4 volts.
The GCP calculates fuel delivery based on throttle valve
angle (operator demand). A hard failure in the TP
sensor 5 volt reference or signal circuits for greater than
2 consecutive seconds will set a DTC 531 or DTC 533.
A hard failure with the TP sensor ground circuit for more
than two consecutive seconds may set DTC 532. If any
(TP) DTC is set the GCP will shut down the engine
immediately.
Specifications:
Range of Measurement: 0-85° (angular)
Measurement Accuracy: ±2% of VREF
Resolution: 0.5° max.
TMAP
Sensor

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Engine distributors DSG-423 Specifications

General IconGeneral
BrandEngine distributors
ModelDSG-423
CategoryEngine
LanguageEnglish

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