Chart C-1D - Map Sensor Output

NOTE: Test numbers refer to numbers on diagnostic chart.

This step checks MAP sensor output voltage to ECM. Without engine running, this voltage represents a barometric reading to ECM.
Applying a vacuum reading of 10 in. Hg to MAP sensor should cause voltage to be 1.2-2.3 volts less than voltage in step 1). When applying vacuum to sensor, change in voltage should be instantaneous. A slow voltage change indicates a faulty sensor.
This step checks vacuum hoses to sensor for leaks and restrictions. Ensure no other vacuum devices are connected to MAP sensor hose.

Fig 1: Chart C-1D Schematic - MAP Sensor Output

Courtesy of ISUZU MOTOR CO.

Fig 2: Chart C-1D Flow Chart - MAP Sensor Output

Courtesy of ISUZU MOTOR CO.