No Change In MAP From Start to Run

Name of Code:
No Change in MAP From Start to Run

When Monitored:
With engine rpm above 400 but less than 1500 and the throttle body at closed throttle.

Set Condition:
To small a difference is seen between barometric pressure at ignition on and manifold vacuum (engine running) for 1.72 seconds.

Theory of Operation:
This sensor measures manifold absolute pressure and ambient barometric pressure with in the manifold. It provides a 0 to 5-volt signal to PCM cavity A27. The MAP sensor puts out a low voltage signal (0.5 to 1.8 volts) at idle when I he manifold vacuum is high, and a higher voltage signal (3.5 to 4.8 volts at deep throttle when the manifold vacuum is low. The MAP receives a 5-volt supply from PCM cavity Al 7 voltage may vary from 4.8 to 5.1 volts. The sensor ground is provided by PCM cavity A4.

Possible Causes:
- Restricted or leaking vacuum pressure to MAP sensor
- Ice in sensor or passage
- Failed sensor
- Failed PCM