S15/T15 2WD Jimmy L4-151 2.5L (1985)
Wiring Diagram For Chart C-1D - Map Output Check
CHART C-1D - MAP OUTPUT CHECK
Circuit Description:
The Manifold Absolute Pressure (MAP) Sensor measures manifold pressure (vacuum) and sends that signal to the ECM. The ECM uses this information
for fuel and spark control.
Test Description:
1.
Checks MAP sensor output voltage to the ECM. This voltage, without engine running, represents a barometer reading to the ECM.
2.
Applying 34 kPa (10 inches Hg) vacuum to the MAP sensor should cause the voltage to be 1.2 volts less than the voltage at Step 1. Upon applying
vacuum to the sensor, the change in voltage should be instantaneous. A slow voltage change indicates a faulty sensor.
3.
Check vacuum hose to sensor for leaking or restriction. Be sure no other vacuum devices are connected to the MAP hose.
