MAP Sensor Voltage Too Low
Name of Code:MAP Sensor Voltage Too Low
When Monitored:
With engine rpm above 400 but less than 1,500 and the TP sensor voltage less than 1.0 volt.
Set Condition:
The MAP sensor signal voltage is below 1.2 volts at start, or below 0.02 volt for 1.76 seconds with engine running.
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:
- Open 5-volt supply circuit
- Signal circuit shorted to ground
- Failed sensor
- PCM failure
- Connector terminals
- Connector wires