Component Tests and General Diagnostics

ECM POWER SOURCE CIRCUIT

CIRCUIT DESCRIPTION

When the ignition switch is turned on, battery positive voltage is applied to 1G2 Relay, terminal IGSW of the ECM and the E.F.I. ECU relay control circuit in the ECM sends a signal to terminal MREL of the ECM by switching on the E.F.I. ECU relay.

This signal causes current to flow to the coil, cutting off the contacts of the E.F.I. ECU relay and supplying power to terminals +B of the ECM.

Wirig Diagram:

Step 1 - 3:

Step 4 - 6:

Step 7 - 9:

Step 10:

INSPECTION PROCEDURE