MFI Control Relay and Ignition Switch-IG

MFI CONTROL RELAY AND IGNITION SWITCH - IG

Description
When the ignition switch is turned on, battery voltage is applied from the ignition switch to the engine control module. This turns ON the ignition power transistor and energizes the MFI control relay coil. This turns ON the MFI control relay switch and power is supplied from the battery to the engine control module through the MFI control relay switch.





Circuit Diagram

Using scan Tool

Harness Inspection Procedure

Control Relay Inspection

NOTE: When applying battery voltage directly, make sure that it is applied to correct terminal. Otherwise, the relay could be damaged.

Fig. 1 Control Relay Test:

1. Connect a 12V power supply (+) terminal to the terminal 6 of the MFI control relay and measure the voltages at terminal 1 when the (-) terminal is connected to and disconnected from the terminal 8.

Fig. 2 Control Relay Testing:

2. Connect a 12V power supply (-) terminal to the terminal 10 of the control relay and check the continuity between terminals 3 and 4 when the (+) terminal is connected to and disconnected from the terminal 7.








3. Connect a 12V power supply (+) terminal to the terminal 3 of the MFI control relay and measure the voltages at the terminal 4 when the (-) terminal is connected to and disconnected from the terminal 9.
4. if one of the above is improper, replace the MFI control relay.