Hyundai Sonata LF: Engine Control System / Manifold Absolute Pressure Sensor (MAPS) Description and Operation
Manifold Absolute Pressure Sensor (MAPS) is a speed-density
type sensor and is installed on the surge tank. It senses absolute
pressure of the surge tank and transfers the analog signal proportional
to the pressure to the ECM. By using this signal, the ECM calculates the
intake air quantity and engine speed.
The MAPS consists of a piezo-electric element and a hybrid IC
amplifying the element output signal. The element is silicon diaphragm
type and adapts pressure sensitive variable resistor effect of
semi-conductor. Because 100% vacuum and the manifold pressure apply to
both sides of the sensor respectively, this sensor can output analog
signal by using the silicon variation proportional to pressure change.

Inspection
Throttle Position Sensor (TPS)
1.
Connect the GDS on the Data Link Connector (DLC).
2.
Start the engine and measure the output voltage of TPS 1 and 2 at C...
Other information:
C..
Brake Booster Operating Test
For simple checking of the brake booster operation, carry out the following tests.
1.
Run the engine for one or two minutes, and then stop it. If
the pedal depresses fully the first time but gradually becomes higher
when depressed succeeding times, the booster is operating properly, if
the pedal height remains unchanged, the booster is inoperative...