Barometric and Absolute Pressure Sensor

Description: On gasoline engines, the Manifold Absolute Pressure (MAP) sensor senses atmospheric pressure to produce an electrical signal. The frequency of this signal varies with intake manifold pressure. The MAP sensor sends this signal to the processor assembly (12A650). The processor assembly uses this signal to determine altitude. The processor assembly then adjusts the E40D shift schedule for the altitude.

On diesel engines, the Barometric Pressure (BP) sensor operates similar to the MAP sensor. It measures barometric pressure instead of intake manifold pressure. The transmission processor assembly (1 2B565) uses the signal from the BP sensor to determine the altitude at which the vehicle is operating. The processor assembly then adjusts the E40D shift schedule for the altitude.

Transmission function: Adjust shift schedule and TV pressure for altitude affects, engine torque calculation

Symptoms: Firm shift feel, late shifts at altitude

Test codes 22, 72