WORKHORSE CUSTOM CHASSIS
Service Manual
2007 W Series
SECTION
7.2
PAGE
114
Automatic Transmission – Allison
2007 W Series Chassis
© 2006 Workhorse Custom Chassis — All Rights Reserved
WSM082106
DTC P0562
Circuit Description
The transmission control module (TCM) requires a
switched ignition voltage to operate. The voltage signal
should be direct from the ignition switch to avoid any
interference.
DTC P0562 is a type C DTC.
DTC Descriptor
This diagnostic procedure supports the following DTC:
• DTC P0562 System Voltage Low
Conditions for Running the DTC
• The components are powered and ignition voltage is
greater than 9.0 volts and less than 18 volts.
• The engine speed is greater than 450 RPM for 10
seconds.
Conditions for Setting the DTC
DTC P0562 sets when the TCM detects ignition
voltage below 8.0 volts at 0°C (32°F) for a total of 5
out of 7 seconds. The voltage threshold is temperature
dependant, varying from 5.0 volts at -60°C (-76°F) to 9.0
volts at 20°C (68°F).
Action Taken When the DTC Sets
• The TCM does not illuminate the malfunction indicator
lamp (MIL).
• The transmission fails to hydraulic default.
• DTC P0562 is stored in TCM history.
• The TCM inhibits torque converter clutch (TCC)
engagement.
• The TCM freezes shift adapts.
Conditions for Clearing the DTC
• A scan tool can clear the code from the TCM history. The
TCM automatically clears the DTC from TCM history if
the vehicle completes 40 warm-up cycles without failure.
Diagnostic Aids
• Inspect the wiring for poor electrical connections at the
TCM. Inspect for the following conditions:
– A bent terminal
– A backed-out terminal
– A damaged terminal
– Poor terminal tension
– A chafed wire
– A broken wire inside the insulation
• When diagnosing for an intermittent short or open,
massage the wiring harness while watching the test
equipment for a change.
• You may have to drive the vehicle in order to experience
a condition.
• Inspect for the presence of aftermarket accessories,
such as a remote starter, etc. Depending on how these
aftermarket accessories are installed, they may interfere
with the required voltage for proper operation of the
transmission.
