User Manual

75
UT108/109 OPERATING MANUAL
UT108/109 OPERATING MANUAL
76
4.Absolute Pressure (MAP) and Baro Sensor (see gure 25)
The MAP sensor is used to change a pressure signal into a DC voltage or frequency
one. All GM, Chrysler, Honda and Toyota use DC voltage type MAP sensors, while
Ford uses frequency type MAP sensors. Refer to relevant manuals for other automotive
manufacturers.
Testing Procedure:
(1) Connect the DC voltage type MAP sensor in the DC voltage testing method and set
the rotary switch to DCV.
(2) Connect the frequency type MAP sensor in the RPMx10 testing method and set the
meter to the number of cylinders in the automobile.
(3) Taking 4 cylinders (4CYL) for example, connect the black test lead probe of the meter
to the ground terminal (i.e. ground strap connection) and connect the red one as
illustrated in gure 25.
(4) Turn on the ignition key but do not start the engine.
Displayed Values:
DC Voltage Type Sensor: In a vacuum state, the displayed value is generally between 3 V
and 5 V. (The details shall be based on the parameters furnished by the supplier.)
Frequency Type Sensor: In a vacuum state, the displayed value is generally 4770 RPM
±5%. (This only applies to the MAP sensor produced by Ford and the other sensors shall