Supra Sport Roof L6-2997cc 3.0L DOHC MFI (1998)
Engine Control Module: Testing and Inspection
Related Diagnostic Procedures
ECM Power Source Circuit
CIRCUIT DESCRIPTION
When the ignition switch is turned ON, battery positive voltage is applied to the terminal IGSW of the ECM and the EFI main relay (Making: EFI
MAIN) control circuit in the ECM sends a signal to the terminal MREL of the ECM switching on the EFI main relay.
This signal causes current to flow to the coil, closing the contacts of the EFI main relay and supplying power to the terminals +B of the ECM.
If the ignition switch is turned off, the ECM continues to switch on the EFI main relay for a maximum of 2 seconds for the initial setting of the AC
valve.
WIRING DIAGRAM
Step 1
