WORKHORSE CUSTOM CHASSIS
Service Manual
Automatic Transmission – Allison
2007 W Series
© 2006 Workhorse Custom Chassis — All Rights Reserved
SECTION
7.2
PAGE
283
2007 W Series Chassis
WSM082106
– 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.
• When DTC P0757 and P0847 are set in combination,
this may indicate a short to ground is present at the
pressure switch circuit or the shift valve is stuck in the
stroked state.
• You may have to drive the vehicle in order to experience
a condition.
• This DTC may indicate that SS2 is mechanically
defective or shift valve 2 is stuck in the stroked state.
Test Description
The numbers below refer to the step numbers on the
diagnostic table.
5. This step tests the TCM response function.
6. This step tests the transmission wiring harness
integrity.
7. This step tests and evaluates the internal wiring
harness.
8. This step tests the PSM for a failed condition.
DTC P0847
Step
Action
Yes
No
Schematic Reference: Automatic Transmission Controls Schematics
1
Did you perform the Diagnostic System Check - Vehicle?
Go to Step 2
Go to Diagnostic
System Check - Vehicle