WORKHORSE CUSTOM CHASSIS
Service Manual
Automatic Transmission – Allison
2007 W Series
© 2006 Workhorse Custom Chassis — All Rights Reserved
SECTION
7.2
PAGE
315
2007 W Series Chassis
WSM082106
a condition.
• This DTC could indicate a hydraulic leak path exhausting
pressure from the reverse PS4.
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 P0878
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
2
Measure the transmission fluid level. Refer to Transmission Fluid Checking .
Is the transmission fluid level correct?
Go to Step 3
Go to Transmission
Fluid Checking
3
Measure line pressure. Refer to Line Pressure Check .
Is the pressure within the specified value?
Go to Step 4
Go to Symptoms -
Automatic Transmission