DANA TM4 SUMO MD MV, Troubleshooting Manual

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40
Service Codes
TT03: Vaux too low
Description
The Auxiliary vehicle battery voltage (Vaux) is the low
voltage battery (12 V to 24 V) for providing power to
the MCU.
This Troubleshooting Tree indicates that the voltage
of the Vaux was lower than 7.5 V for at least 1
millisecond, which is the low limit for normal operation
of the auxiliary vehicle battery. As this is only a
warning, the system will still function as it displays this
message.
The most likely cause of this warning is that the DCDC
system is not regulating the auxiliary voltage correctly.
It may be caused by the activation of another high
auxiliary load.
The auxiliary vehicle battery itself may be defective.
There may be a bad connection between the auxiliary
vehicle battery and the MCU. In this case, the user
may require specialized equipment to diagnose this
fault. This can be also that the
Vaux Fuse about to open
or more resistive.
The MCU itself may be defective.
Note : Refer to the TM4 Product installation guide for
more details on installation and deinstallation
procedure including safety warning considerations.
To correctly diagnose the faulty system, connect the
Diagnostic Tool (see «Diagnostics» section for test
equipment and descriptions) and follow the
troubleshooting tree procedure below.
See “Safety Warnings” and “Troubleshooting Tips”
sections
for general guidelines on system
diagnostics.
System Mode Referred by
SysFile ID Condition Possible Causes
Operational 0x0313
MCU detected an
auxiliary vehicle battery
voltage that was too low.
1.
DCDC not regulating auxiliary DC voltage
correctly.
2.
High auxiliary load being activated
causing voltage drop.
3.
The auxiliary vehicle battery does not
operate correctly.
4.
Intermittent or bad Vaux connection at the
MCU.
5.
Vaux Fuse about to open or more
resistive.
6.
Defective MCU.