ECM Power and Ground Circuit Check

ECM Power and Ground Circuit Check

Wiring Diagram:

Circuit Description
When the ignition switch is turned ON, the main relay turns ON (the contact point closes) and the main power is supplied to ECM. And then ECM supplies 5 V power to each sensor (MAP sensor, A/C refrigerant pressure sensor, TP sensor and pressure sensor (included in EVAP leak check module)).
If 5 V power circuit to each sensors from ECM is shorted to ground, ECM stops engine and emission control operation.

Step 1-4 (Continued):

Step 4 (Continued)-8 (Continued):

Step 8 (Continued)-11:

Step 12:

Troubleshooting


NOTE:
- Before performed troubleshooting, be sure to read the Precautions of ECM Circuit Inspection.
- When measuring circuit voltage, resistance and/or pulse signal at ECM connector, connect the special tool to ECM and/or the ECM connectors referring to Inspection of ECM and Its Circuits.