WORKHORSE CUSTOM CHASSIS
Service Manual
2007 W Series
SECTION
7.2
PAGE
332
Automatic Transmission – Allison
2007 W Series Chassis
© 2006 Workhorse Custom Chassis — All Rights Reserved
WSM082106
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.
• DTC P0960, set in combination with DTC P2727 and
P2761, may indicate an open in the high side driver
circuit.
Test Description
The numbers below refer to the step numbers on the
diagnostic table.
3. This step tests the command signal from the TCM.
4. This step tests the resistance value of the external
harness and solenoid.
5. This step tests the resistance value of the solenoid
and tests the internal wiring harness for opens.
6. This step tests the resistance value of the solenoid.