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

Control Relay Test I:

Control Relay Test II:

Control Relay Test III:

Control Relay Test IV:

NOTE: When applying voltage directly to relay, be sure it is being applied to the correct terminal, as relay may be damaged otherwise.
1. Remove the cover under the glove box and disconnect the control relay.
2. Connect a 12V power source to terminal 10 of the relay and measure the voltage present at terminals 4 and 5. No voltage should be present, if voltage is present replace the relay.
3. Connect terminals - and 8 with a jumper wire, and with the 12V source still connected measure the voltage present at terminals 4 and 5. Battery voltage should be pressent at both terminals if voltage is not present at both terminals replace the relay.
4. Test for continuity between terminals 2 and 3. If there is continuity replace the relay.
5. Connect a 12V power source to terminal 9, and ground terminal 6. Test for continuity between terminals 2 and 3. There should now be continuity, if there is no continuity replace the relay.
6. Connect a 12V power source to terminal 3 and ground terminal 7. Measure the voltage at terminal 2. There should be battery voltage at terminal 2, if there is no voltage, replace the relay.
7. Disconnect the ground from terminal 7 and measure the voltage at terminal 2. If there is still voltage present at terminal 2 replace the relay.
8. If the relay passed all tests the problem is in either the relay circuit or the Electronic Control Unit (ECU).