Main Relay (Computer/Fuel System): Testing and Inspection

1. Remove the Multipoint Fuel Injection (MFI) relay.
2. Check the continuity between the MFI relay terminals.

Inspection terminals Continuity





3. Use jumper leads to connect MFI relay terminal 7 to the battery (+) terminal and terminal 5 to the battery (-) terminal.

CAUTION: If jumper leads are not connected properly, the relay will be damaged.





4. Check the Voltage at MFI relay terminal 1 while connecting and disconnecting the jumper lead at the battery (-) terminal.

Jumper lead Voltage at terminal 1

Connected System Voltage
Disconnected 0 Volts





5. Use the jumper leads to connect MFI relay terminal 8 to the battery (+) terminal and terminal 6 to the battery (-) terminal.
6. Check the continuity between MFI relay terminals 2 - 4 and terminals 3 - 4 while connecting and disconnecting the jumper lead at the battery (-) terminal.





7. If there is a defect, replace the MFI relay.