WORKHORSE CUSTOM CHASSIS
Service Manual
2007 W Series
SECTION
7.2
PAGE
308
Automatic Transmission – Allison
2007 W Series Chassis
© 2006 Workhorse Custom Chassis — All Rights Reserved
WSM082106
DTC P0873
Step
Action
Yes
No
12
Replace the PSM. Refer to Pressure Switch Manifold Replacement .
Did you complete the replacement?
Go to Step 16
—
13
Replace the AT internal wiring harness. Refer to Wiring Harness Replacement .
Did you complete the replacement?
Go to Step 16
—
14
Test the PS3 circuit between the TCM and the AT inline 20-way connector for an open
or short condition. Refer to Circuit Testing .
Did you find and correct the condition?
Go to Step 16
—
15
IMPORTANT:
Prior to replacing the TCM, swap the TCM with a known good TCM.
Prior to replacing the TCM, swap the TCM with a known good TCM.
In most cases, the TCM is not at fault. Investigate thoroughly before
In most cases, the TCM is not at fault. Investigate thoroughly before
replacing the TCM.
replacing the TCM.
Replace the TCM. Refer to Control Module References for replacement, setup, and
programming.
Did you complete the replacement?
Go to Step 13
—
16
Perform the following procedure in order to verify the repair:
1. Clear the DTC.
2. Start the engine.
3. Using the scan tool, monitor PS3 status.
4. Select Specific DTC.
5. Enter DTC P0873.
Has the test run and passed?
Go to Step 17
Go to Step 2
17
With the scan tool, observe the stored information, capture info, and DTC Info.
Does the scan tool display any DTCs that you have not diagnosed?
Go to Diagnostic
Trouble Code (DTC)
List - Vehicle
System OK
