No Change In MAP From Start to Run

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

When Monitored:
Engine is idling with a stable RPM (RPM fluctuation less than 64 RPM) and the vehicle is not moving.

Set Condition:
Too small a difference is seen between barometric pressure at ignition on and manifold vacuum.

Theory of Operation:
This sensor measures manifold absolute pressure and ambient barometric pressure within the manifold. It provides a 0 to 5-volt signal to PCM cavity 36. The MAP sensor puts out a low voltage signal (0.5 to 1.8 volts) at idle when the manifold vacuum is high, and a higher voltage signal (3.9 to 4.8 volts) at deep throttle when the manifold vacuum is low. The MAP receives a 5-volt supply from PCM cavity 61; voltage may vary from 4.8 to 5.1 volts. The sensor ground is provided by PCM cavity 43.

Possible Causes:
- Restricted or leaking vacuum/pressure to MAP sensor
- Ice in sensor or passage
- Failed sensor
- PCM failure
- Connector terminals
- Connector wires