CBR-2295 202307 Service Bulletin/Repair Instructions

Uncontrolled Copy
ID #
CBR-2295
Version
3
Print
Title

Battery Electric Vehicle (BEV) - Diagnostic Trouble Code (DTC) Troubleshooting Ending In No Fault Found

Abstract

Additional information for fault code diagnostics resulting in no fault found

Content
If a BEV has active diagnostic trouble codes the first steps should be to check all grounds for a good clean and tight

connection.

For a complete list of ground locations refer to the description, design and function document in Impact titled Electrical

Power and Ground System Description under function group 37. See example image below.

;
Tags
Live UI

bev
mack
volvo
ground
Categories
Make and Model > Mack > LR Electric

Make and Model > Volvo > VNR Electric

Vehicle System > Battery Electric Systems
; Live UI
IMPACT 4.07.170
7/25/2023
Electrical Power and Ground, System Description

Electrical power and ground, system description

Overview

Description

12 V grounding

24 V grounding

600 V grounding

24 V power

600 V power
Electrical power and ground, system description
Overview

12 V grounding
1
Chassis ground (X136)

(front left)
2
Chassis ground (X135)

(front right)
24 V grounding locations

Copyright to this documentation belongs to the Volvo Group. No reproduction, copying, change, amendment or other similar disposal is entitled without prior written consent by

the Volvo Group

The information contained herein is current at the time of its original distribution, but is subject to change. The reader is advised that printed copies are uncontrolled.
2 / 17
IMPACT 4.07.170
1
7/25/2023
Ground junction (X87)

(front)
2
Chassis ground (X911)

(front right)
3
Chassis ground (X912)

(mid right)
4
Chassis ground (X86)

(right)
5
Chassis ground (X913)

(mid right)
600 V grounding locations
Copyright to this documentation belongs to the Volvo Group. No reproduction, copying, change, amendment or other similar disposal is entitled without prior written consent by

the Volvo Group

The information contained herein is current at the time of its original distribution, but is subject to change. The reader is advised that printed copies are uncontrolled.
3 / 17
IMPACT 4.07.170
1
7/25/2023
Ground bar MPB (Modular Power Box) (X85)

(front)
2
Ground bar (X81)

(chassis center)
3
Ground bar (X82)

(chassis center left)
4
Ground bar (X83)

(chassis rear left)
24 V power locations
Copyright to this documentation belongs to the Volvo Group. No reproduction, copying, change, amendment or other similar disposal is entitled without prior written consent by

the Volvo Group

The information contained herein is current at the time of its original distribution, but is subject to change. The reader is advised that printed copies are uncontrolled.
4 / 17
IMPACT 4.07.170
1
7/25/2023
Heater relay

(front)
2
Six-way junction box
3
Fuse box FM21
4
24 V battery
5
Six-way junction box
600 V power locations
Copyright to this documentation belongs to the Volvo Group. No reproduction, copying, change, amendment or other similar disposal is entitled without prior written consent by

the Volvo Group

The information contained herein is current at the time of its original distribution, but is subject to change. The reader is advised that printed copies are uncontrolled.
5 / 17
IMPACT 4.07.170
7/25/2023
1
CSU (Charging Switch Unit)
2
EMD (Electric Motor Drive)
3
TVJB (Traction Voltage Junction Box) (7 HCC (High-Current Connection) and 0 LCC (LowCurrent Connection))
4
TVJB (2 HCC and 5 LCC)
Description

The electrical components of the vehicle must be grounded to function properly. One of the most

important reasons for grounding is to protect the electrical components and vehicle from electrical

surges. The main ground stud completes vehicle circuits by serving as a return path for the flow of

current. Vehicle electrical components are either grounded directly to the main ground stud on the

side member (frame rail) or to the other ground studs located throughout the vehicle.

Electrical power is necessary for all the electrical components to function. Electrical power is

supplied to all the electrical components by power connections through cables and terminals.
12 V grounding
Copyright to this documentation belongs to the Volvo Group. No reproduction, copying, change, amendment or other similar disposal is entitled without prior written consent by

the Volvo Group

The information contained herein is current at the time of its original distribution, but is subject to change. The reader is advised that printed copies are uncontrolled.
6 / 17
IMPACT 4.07.170
7/25/2023
Chassis ground front left (X136)

One cable is connected at this grounding point. The cable is connected from the chassis ground front

left (X136) to the chassis ground front right (X135). The cable is also connected from chassis ground

front left (X136) to fuses, switches and control units.
Chassis ground front right (X135)

Chassis ground front right (X135) is connected to chassis ground front left (X136).
24 V grounding
Copyright to this documentation belongs to the Volvo Group. No reproduction, copying, change, amendment or other similar disposal is entitled without prior written consent by

the Volvo Group

The information contained herein is current at the time of its original distribution, but is subject to change. The reader is advised that printed copies are uncontrolled.
7 / 17
IMPACT 4.07.170
7/25/2023
Ground junction front (X87)

Ground junction front (X87) is connected to chassis ground front left (X136), a six way junction box,

chassis ground mid right (X86) and grounds the following:

●
PUCU (PUmp Control Unit)
●
Heater
●
Battery equalizer
●
FRC (Fuse and Relay Center)
●
CSU
●
Electronic unit cooling/conversion box.
Chassis ground front right (X911)

Chassis ground front right (X911) is connected to a six-way junction box (X86) located on the righthand side of the vehicle and grounds the 24 V batteries.
Chassis ground mid right (X912)

Chassis ground mid right (X912) grounds the following:

●
EHPS (Electro-Hydraulic Power Steering)
●
Air compressor.
Chassis ground right (X86)

Copyright to this documentation belongs to the Volvo Group. No reproduction, copying, change, amendment or other similar disposal is entitled without prior written consent by

the Volvo Group

The information contained herein is current at the time of its original distribution, but is subject to change. The reader is advised that printed copies are uncontrolled.
8 / 17
IMPACT 4.07.170
7/25/2023
Chassis ground right (X86) grounds the 12 V batteries and is connected to the chassis ground front

right (X911). The chassis ground right (X86) is also connected to the DC/DC converter and to the

ground junction front (X87).
Chassis ground mid right (X913)

Chassis ground mid right (X913) grounds the heater. The heater is used to heat the traction batteries.
600 V grounding
Ground bar MPB front (X85)

Ground bar MPB front (X85) is connected to the ground bar chassis center (X81) and grounds the

electrical components such as:

●
TVMU (Traction Voltage Monitoring Unit)
●
TVJB (2 HCC and 5 LCC)
●
CSU
●
DC/DC converters.
Ground bar chassis center (X81)

Ground bar chassis center (X81) is connected to the ground bar MPB front (X85), the ground bar

chassis center left (X82) and the chassis ground mid left (X83). The ground bar chassis center (X81)

grounds the following:

●
EPS (Electric Propulsion System)
Copyright to this documentation belongs to the Volvo Group. No reproduction, copying, change, amendment or other similar disposal is entitled without prior written consent by

the Volvo Group

The information contained herein is current at the time of its original distribution, but is subject to change. The reader is advised that printed copies are uncontrolled.
9 / 17
IMPACT 4.07.170
●
EMD
●
TVJB (7 HCC and 0 LCC).
7/25/2023
Ground bar chassis center left (X82)

Ground bar chassis center left (X82) is connected to the ground bar chassis center (X81) and

grounds the traction batteries.
Ground bar chassis rear left (X83)

Ground bar chassis rear left (X83) is connected to the ground bar chassis center (X81) and grounds

the electrical components such as:

●
EMD
●
ePTO (electromobility Power Take-Off)
●
Traction batteries.
24 V power

Heater relay
The power flows from a six-way junction box (1) to the three heater relays (3) via a fuse box FM22 .

(2) Fuses are used to limit the electrical current flowing through the wires to protect certain

components. The components connected to the heater relay are the heater (5) and the fuse box

FM20 . (4) The heater relays are connected to the ESS (Energy Storage System) through cables.

The power to run the heater ESS is supplied through these cables.
Six-way junction box

Copyright to this documentation belongs to the Volvo Group. No reproduction, copying, change, amendment or other similar disposal is entitled without prior written consent by

the Volvo Group

The information contained herein is current at the time of its original distribution, but is subject to change. The reader is advised that printed copies are uncontrolled.
10 / 17
IMPACT 4.07.170
7/25/2023
The six-way junction box (1) is connected to the main switch (2) , fuse box FM21 (3) and fuse box

FM20 (4) .
Also, the six-way junction box (1) is connected to the main switch (2), fuse (3) and fuse box FM23 .

(4) The main switch is an automatic switch and it disconnects many electrical components and

functions in the 24 V system.
Copyright to this documentation belongs to the Volvo Group. No reproduction, copying, change, amendment or other similar disposal is entitled without prior written consent by

the Volvo Group

The information contained herein is current at the time of its original distribution, but is subject to change. The reader is advised that printed copies are uncontrolled.
11 / 17
IMPACT 4.07.170
7/25/2023
Fuse box (FM21)
The power flows from the fuse box FM21 (1) to the EHPS (2) and the relay (3) . From the relay, the

power flows to the coolant heater. The purpose of the electrical coolant heater is to heat the ESS by

circulating the coolant through the ESS coolant circuit. The EHPS is an electro-hydraulic unit that

provides the necessary energy to ensure the performance of power steering on the vehicle.
24 V battery
Copyright to this documentation belongs to the Volvo Group. No reproduction, copying, change, amendment or other similar disposal is entitled without prior written consent by

the Volvo Group

The information contained herein is current at the time of its original distribution, but is subject to change. The reader is advised that printed copies are uncontrolled.
12 / 17
IMPACT 4.07.170
7/25/2023
The 24 V battery (5) receives its power supply from a six-way junction box (1) via the main switch (3)

, fuse (2) and fuse box FM23 . (4) The power is also supplied to the battery equalizer (6) . The 24 V

DC (Direct Current) system provides power and controls all the 24 V DC electrical and electronic

components. 24 V DC also enables the traction voltage system components to communicate and

transfer signals between different control units. The 24 V DC system is powered by two 12 V

batteries.
Six-way junction box
Copyright to this documentation belongs to the Volvo Group. No reproduction, copying, change, amendment or other similar disposal is entitled without prior written consent by

the Volvo Group

The information contained herein is current at the time of its original distribution, but is subject to change. The reader is advised that printed copies are uncontrolled.
13 / 17
IMPACT 4.07.170
7/25/2023
The power flows from the six-way junction box (2) to the DC/DC converters (3) . The DC/DC

converters convert 600 V DC to 24 V DC and are connected to the grounding points such as chassis

ground (front right) (X911) and ground junction front (X87) via MPB box (1) .
600 V power

CSU
Copyright to this documentation belongs to the Volvo Group. No reproduction, copying, change, amendment or other similar disposal is entitled without prior written consent by

the Volvo Group

The information contained herein is current at the time of its original distribution, but is subject to change. The reader is advised that printed copies are uncontrolled.
14 / 17
IMPACT 4.07.170
7/25/2023
The power flows from TVJB (4) (7 HCC and 0 LCC) to the CSU (1) . The CSU is a part of the

electrical interface between the DC charging inlet and the traction voltage system. The components

connected to the CSU are TVJB (2) (2 HCC and 5 LCC) and CCS (Combined Charging System) (3) .
EMD
Power flows from the EMD (1) to the electric motor (3) . The EMD activates and deactivates the

power electronics and the torque capability of the MDS (Motor Drive System) on request from the

PCM (Powertrain Control Module) and the HPCU (Hybrid Powertrain Control Unit). The components

connected with EMD are the electric motor and TVJB (2) (7 HCC and 0 LCC).
TVJB (7 HCC and 0 LCC)
Copyright to this documentation belongs to the Volvo Group. No reproduction, copying, change, amendment or other similar disposal is entitled without prior written consent by

the Volvo Group

The information contained herein is current at the time of its original distribution, but is subject to change. The reader is advised that printed copies are uncontrolled.
15 / 17
IMPACT 4.07.170
7/25/2023
The power from TVJB (1) (7 HCC and 0 LCC) flows to the traction battery (2) . The TVJB electrically

connects to the different types of traction voltage components in the EPS.
The power from EMD (2) flows to the TVJB (1) (7 HCC and 0 LCC). The TVJB (7 HCC and 0 LCC) is

also connected to the traction batteries (3).
Copyright to this documentation belongs to the Volvo Group. No reproduction, copying, change, amendment or other similar disposal is entitled without prior written consent by

the Volvo Group

The information contained herein is current at the time of its original distribution, but is subject to change. The reader is advised that printed copies are uncontrolled.
16 / 17
IMPACT 4.07.170
7/25/2023
The TVJB (1) (7 HCC and 0 LCC) also supplies the power to the EMD (3) and ePTO (2). The ePTO

is an electrical power take-off that consists of an electric machine EM (Electric Motor) and a

hydraulic pump.
TVJB (2 HCC and 5 LCC)
The power flows from TVJB (1) to the traction battery (2) .

Copyright to this documentation belongs to the Volvo Group. No reproduction, copying, change, amendment or other similar disposal is entitled without prior written consent by

the Volvo Group

The information contained herein is current at the time of its original distribution, but is subject to change. The reader is advised that printed copies are uncontrolled.
17 / 17

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