WORKHORSE CUSTOM CHASSIS
Service Manual
Automatic Transmission – Allison
2007 W Series
© 2006 Workhorse Custom Chassis — All Rights Reserved
SECTION
7.2
PAGE
321
2007 W Series Chassis
WSM082106
DTC P0880
Step
Action
Value
Yes
No
5
1. Turn the ignition OFF.
2. Disconnect the 80-way connector at the TCM.
3. Install the J 39700 breakout box, the J-47275 breakout box adapter
and the J 47275-1 magnetic overlay.
4. Turn the ignition ON, with the engine OFF.
5. Using the DMM, measure the voltage between connector terminal 9
and terminal 63.
6. Turn the ignition OFF.
7. Measure the voltage between connector terminal 63 and terminal 69.
8. Subtract the voltage reading obtained in sub-step 5 from the voltage
reading obtained in sub-step 3.
Is the voltage greater than the specified value?
0.5 V
Go to Step 6
Go to Step 8
6
1. Turn the ignition ON, with the engine OFF.
2. Using the DMM, measure the voltage between connector terminal 9
and terminal 10.
3. Measure the voltage between connector terminal 9 and terminal 70.
4. Turn the ignition OFF, monitoring the system voltage during shut-
down.
Was a loss of voltage detected?
—
Go to Step 7
Go to Step 8
7
1. Inspect the transmission wiring harness assembly.
2. Repair the transmission wiring harness assembly. Refer to Circuit
Tsting and Wiring Repairs .
Did you complete the repair?
—
Go to Step 9
—
8
IMPORTANT:
In most cases, the TCM is not at fault. Investigate thorough-
In most cases, the TCM is not at fault. Investigate thorough-
ly before replacing the TCM. Swap the TCM with a known
ly before replacing the TCM. Swap the TCM with a known
good TCM to confirm diagnosis.
good TCM to confirm diagnosis.
Replace the TCM. Refer to Control Module References for replacement,
setup, and programming.
Did you complete the replacement?
—
Go to Step 9
—
