Ignition
90-8M0050731 MAY 2011 Page 2A-25
Manifold Absolute Pressure (MAP) Sensor
The manifold absolute pressure (MAP) sensor measures the changes in the intake manifold pressure. It is located at the top of
the intake manifold. When the key is turned "ON" the MAP sensor reads the ambient atmospheric pressure. This information is
used by the PCM as an indication of altitude and is referred to as BARRO. The manifold absolute pressure will change as a result
of engine load and speed changes.
Manifold Absolute Pressure Sensor Test
1. Start the engine and connect the CDS to the engine. If the MAP sensor does not appear to be indicating a pressure change,
shake or move the sensor harness and connector. If the pressure begins to change, look for broken, loose, or corroded wires.
Computer Diagnostic System (CDS) Order through SPX
Adapter Harness 84‑822560A13
Extension Cable 84‑825003A 1
2. Turn the ignition key switch to the "OFF" position. Disconnect the engine harness connector from the MAP sensor.
3. Visually inspect the MAP sensor pins and the wires coming from the connector. Look for broken, bent, or corroded pins at
the MAP sensor; and loose, broken, or corroded wires at the engine harness connector.
4. Use the DMT 2004 digital multimeter to perform an ohm check between the MAP sensor pins A, B, and C.
a - Pin C
b - Pin A
c - Pin B
d - MAP sensor
DMT 2004 Digital Multimeter 91‑892647A01