DTC 54

DTC 54: Fail-safe Relay
1. Check the ABS + B (20 A) fuse in the under-hood fuse/relay box, and reinstall the fuse if it is OK.
Is the fuse OK?
YES-Go to step 2.
NO-Replace the fuse, and rechecks
2. Reinstall the fuse, and turn the ignition switch ON (II).
Does the fuse blow?
YES-Repair short to body ground in the wire between the fail-safe relay, pump motor relay, VSA relay, VSA-TCS control valve actuator relay, and modulator unit.
NO-Go to step 3.
3. Check the fail-safe relay in the under-hood ABS relay box. The wire colors of the fail-safe relay 4P connector are WHT/GRN, BRN/BLK, BLK, and YEA GRN.
Is the relay 0 V ?
YES-With the fail-safe relay removed, and go to step 4.
NO-Replace the fail-safe relay.





4. Measure the voltage between the fail-safe relay 4P connector terminal No. 1 and body ground.
Is there battery voltage?
YES-Go to step 5.
NO-Repair open in the wire between the underhood fuse/relay box and the fail-safe relay.





5. Connect the fail-safe relay 4P connector terminal No. 1 to No. 2 with a jumper wire.
6. Disconnect modulator unit connector A (10P).





7. Measure the voltage between body ground and terminals No. 9 and No. 10 individually.
Is there battery voltage?
YES-Go to step 8.
NO-Repair open in the wire between the fail-safe relay and the modulator unit.
8. Remove the jumper wire from the fail-safe relay connector.





9. Measure the voltage between body ground and modulator unit connector A (10P) terminals No. 9 and No. 10 individually.
Is there battery voltage ?
YES-Repair short to power in the wire between the ABS pump motor relay, fail-safe relay, VSA relay, VSA-TCS control valve actuator relay, and modulator unit.
NO-Go to step 10.
10. Disconnect VSA control unit connector C (26P).
11. Turn the ignition switch ON (II).





12. Measure the voltage between terminal No. 15 and body ground.
Is there battery voltage?
YES-Repair short to power in the wire between the VSA control unit and the fail-safe relay.
NO-Go to step 13.





13. Check for continuity between VSA control unit connector C (26P) terminal No. 15 and body ground.
Is there continuity?
YES-Repair short to body ground in the wire between the VSA control unit and the fail-safe relay.
NO-Go to step 14.





14. Check for continuity between the fail-safe relay 4P connector terminal No. 3 and body ground.
Is there continuity?
YES-Go to step 15.
NO-Check for an open in the wire between the fail-safe relay and body ground. If the wire is OK, check for poor ground at G202.





15. Connect the fail-safe relay 4P connector terminals No. 3 and No. 4 with a jumper wire.





16. Check for continuity between VSA control unit connector C (26P) terminal No. 15 and body ground.
Is there continuity?
YES-If the problem recurs, check for loose VSA control unit connectors. If necessary, substitute a known-good VSA control unit, and recheck.
NO-Repair open in the wire between the VSA control unit and the fail-safe relay.