DTC 28

TCS DTC 28: TCS Relay
1. Check the TCS (20A) fuse in the under-hood fuse/relay box.
Is the fuse OK?
YES-Reinstall the fuse, and go to step 2.
NO-Replace the fuse, and recheck. If the fuse blows with the ignition switch OFF, repair short to ground between the under-hood fuse/relay box and the TCS relay.
2. Turn the ignition switch ON (II).
Does the fuse blow?
YES-Repair short to body ground in the wire between the TCS relay, and modulator unit.
NO-Go to step 3.
3. Check the TCS relay in the under-hood ABS relay box. The wire colors of the TCS relay 4P connector are BLU, RED/BLU, BRN/BLK, and GRN/YEL.
Is the relay OK?
YES-Do not reinstall the TCS relay, and go to step 4.
NO-Replace the TCS relay.





4. Measure the voltage between the TCS 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 TCS relay.





5. Connect the TCS relay 4P connector terminal No. 1 to No. 2 with a jumper wire.
6. Disconnect the modulator unit 24P connector.





7. Measure the voltage between terminal No.17 and body ground.
Is there battery voltage?
YES-Go to step 8.
NO-Repair open in the wire between the TCS relay and the modulator unit.
8. Remove the jumper wire from the TCS relay 4P connector.





9. Measure the voltage between the modulator unit 24P connector terminal No. 17 and body ground.
Is there battery voltage?
YES-Repair short to power in the wire between the TCS relay and the modulator unit.
NO-Go to step 10.
10. Disconnect ABS/TCS control unit connector B (16P).





11. Measure the voltage between terminal No. 13 and body ground.
Is there battery voltage?
YES-Repair short to power in the wire between the ABS/TCS control unit and the TCS relay.
NO-Go to step 12.





12. Check for continuity between ABS/TCS control unit connector B (16P) terminal No. 13 and body ground.
Is there continuity?
YES-Repair short to body ground in the wire between the ABS/TCS control unit and the TCS relay.
NO-Go to step 13.
13. Turn the ignition switch OFF.
14. Remove the fail-safe relay. The wire colors of the fail-safe relay 4P connector are WHT/GRN, BRN/ BLK, BLK, and YEL/GRN.





15. Connect the fail-safe relay 4P connector terminal No. 1 and No. 2 with a jumper wire.





16. Measure the voltage between the TCS relay 4P connector terminal No. 3 and body ground.
Is there battery voltage?
YES-Go to step 17.
NO-Repair open in the wire between the fail-safe relay and the TCS relay.





17. Connect the TCS relay 4P connector No. 3 and No. 4 with a jumper wire.

NOTE: Make sure the ABS/TCS control unit connector B (16P) is disconnected.





18. Measure the voltage between ABS/TCS control unit connector B(16P) terminal No. 13 and body ground.
Is there battery voltage?
YES-Check for loose ABS/TCS control unit connectors. If necessary, substitute a known-good ABS/TCS control unit, and recheck.
NO-Repair open in the wire between the TCS relay and the ABS/TCS control unit.