ECPC SPN 517081/FMI 14 False Fail for Welded
Contactors BMS3 or BMS4 SPN 517000/FMI 6 or
SPN 517001/FMI 6

TSB-08-001-FTL

Creation Date:2023-12-04
Last Revision Date:2024-04-11

Engine or Vehicle Affected:
pemM2
peCascadia

Description of Revisions: This bulletin replaces the version dated
12/14/2023. Confirming and resolving the false fail fault condition
procedure has been updated.

Warranty applies to this described condition. See the warranty information at the end of this bulletin.

Described Condition

In eCascadia and eM2 vehicles, the fault monitoring diagnostics for the AUX contactors in BMS3 or BMS4 may
trigger a false SPN517000/FMI6 or SPN517001/FMI6 due to incorrectly identifying contactors as being welded.
When a welded contactor condition is active, the high-voltage (HV) startup gets disabled. This incorrect fail
status will be rectified and corrected in a forthcoming software update. In the interim, to verify and rectify the
false fail fault, perform the following procedure when:

¢ ECPC is reporting SPN 517081/FMI 14 and
¢ BMS3 is reporting SPN 517000/FMI 6 or SPN 517001/FMI 6 and the batteries are 2 layer batteries or

¢ BMS4 is reporting SPN 517000/FMI 6 or SPN 517001/FMI 6 and the batteries are 3 layer batteries.

A Danger: Service and repair of the electric vehicle should only be performed by
technicians that have completed HV2 or HV3 Daimler Safety Training.
Decommissioning and commissioning of the HV system should only be
performed by technicians that have completed HV3 Daimler Safety training. To
prevent personal injury or death, or damage to the electric system, do not attempt
repairs yourself.

A Danger: If a collision occurs, do not touch any high voltage cables, connectors,
or components. Doing so could cause severe personal injury or death.

@ Warning: Always disconnect the battery negative (ground) cable before
carrying out repairs or service on the electrical system.

@ Warning: Before attempting any work on the batteries or the electrical system,
remove all metal jewelry. If metal contacts with electrical circuits, a short circuit
may occur causing electrical system failure and damage or personal injury.

1. Park the vehicle on a level surface, place the vehicle in neutral, shut down the vehicle, and set the park
brake. Chock the tires.

2. Decommission the vehicle and verify the high-voltage (HV) system is shut down. See Section 08.08,
Subject 110 of the eCascadia Workshop Manual or Section 08.08, Subject 110 of the eM2 Workshop
Manual for instructions. Is the measurement greater than 12 volts during decommissioning?

a. YES — Stop the decommissioning procedure. Visit the ‘DTTS Cases’ link on the service page of the
DTNA Portal for additional assistance.

b. (No — Go to step 3.

3. Connect all the HV connectors and the cable clamps that were removed during the decommissioning.

4. Remove the cable retention clamp bolt at the battery 2, connector C3. See Fig. 1, item 3.

5. Remove the bolt and install the guide pin tool (DDE DSNEMG022008) on battery 2, connector C3. See Fig.

in

6. _Lift the high-voltage cable (HV) connector C3 from battery 2, remove the guide pin, then install the breakout
box tool (W000588046300) on the battery 2, connector C3.

7. Leave the E-Stop button pressed and Locked Out. Turn the cab load disconnect switch (CLDS) ON and turn
the keyswitch to the ON position.

8. Connect 12 volts DC into the breakout box positive and EQ ground (center banana jack) ports for one
minute. A 12 volt power supply or the vehicle 12 volt battery circuit may be used.

9. Turn the keyswitch to the OFF position and turn the CLDS OFF.

10. Remove the breakout box from battery 2, connector C3.

11. Install the guide pin tool (DDE DSNEMG022008) on battery 2, connector C3.

12. Install the high voltage cable on the battery 2, connector C3. Remove the guide pin, then install the
connector C3 retention bolt and tighten the bolt 14 Ib-ft (19 N-m).

13. Commission the vehicle. See Section 08.08, Subject 110 of the eCascadia Workshop Manual or Section
08.08, Subject 110 of the eM2 Workshop Manual for instructions.

HV battery connector callouts and Aux cable retention clamps

07/25/2023 f080501
1. Connector 1 (C1) 4. Connector 4 (C4)
2. Connector 2 (C2) 5. Connector 5 (C5)

3. Connector 3 (C3)
Fig. 1, HV battery connector callouts and Aux cable retention clamps

Guide Pin

06/20/2023 f080503