ECM Power and Ground Circuit Check
ECM Power and Ground Circuit CheckWiring Diagram
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 (EVAP leak check pressure sensor, A/C refrigerant pressure sensor, APP sensor and TP sensor).
If 5 V power circuit to each sensors from ECM is shorted to ground, ECM stops engine and emission control operation.
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.
Step 1-6:
Step 7-12:
