SFN-20240411B Redesign harness to change to relays

TICO Document #: SFN-20240411B (formerly TES 284)

Complication: Diodes are failing in the emissions harness during normal operation.

Description of Procedure: Design calls for diodes across the coil of the relay and the design had diodes downstream of the relay which are not rated for the current required. Redesign harness to change to relays with diodes across coil.

Units Affected: B6.7 On-Road and Off-Road

Parts Required: On-Road 621695

Off-Road 621694

Planned Labor: 2 hour

Instructions:

1. Park vehicle on flat surface, apply parking brake, and chock wheels. If your company utilizes a “Lock Out, Tag Out” policy, you should employ it during this procedure.

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2. Remove front covers on cab.

3. Remove bolts from relay box

4. Unplug all harness connections

5. Cut any tie straps to remove harness

6. If vehicle has PN 620628 HARNESS-WIRE, 2017 TIER IV FINAL, ISB, EMISSIONS RELAYS, FRONT MOUNT PDC

   6A Replace with PN 621694 HARNESS-WIRE, 2017 TIER IV FINAL, ISB, EMISSIONS RELAYS, FRONT MOUNT PDC

7. If vehicle has PN 620850 HARNESS-WIRE, 2017 ISB, EMISSIONS RELAYS, FRONT MOUNT PDC

   6A Replace with PN 621695 HARNESS-WIRE, 2017 ISB, EMISSIONS RELAYS, FRONT MOUNT PDC

8. Connect all electrical connections

9. Reinstall panels on front of cab

10. Remove “Lock Out, Tag Out” plaque.

11. Return vehicle to service.