WORKHORSE CUSTOM CHASSIS
Service Manual
Automatic Transmission – Allison
2007 W Series
© 2006 Workhorse Custom Chassis — All Rights Reserved
SECTION
7.2
PAGE
365
2007 W Series Chassis
WSM082106
DTC P0974
Step
Action
Value
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
1. Install the scan tool.
2. Turn ON the ignition, with the engine OFF.
IMPORTANT:
Before clearing the DTC, use the scan tool in order to
Before clearing the DTC, use the scan tool in order to
record the Freeze Frame and Failure Records for reference.
record the Freeze Frame and Failure Records for reference.
The Clear Info function will erase the data.
The Clear Info function will erase the data.
3. Record the DTC Freeze Frame and Failure Records.
4. Clear the DTC.
5. Using the scan tool, measure ignition voltage.
Is voltage within the specified value?
9-18 V
Go to Step 3
Go to DTC
P0562 for low
voltage or DTC
P0563 for high
voltage
3
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 ON the ignition, with the engine OFF.
5. Using the DMM, measure the voltage between connector terminal
52 and ground.
6. Using the scan tool, command SS1 to ON.
Is the voltage within the specified value when SS1 is commanded ON?
Less than battery volt-
age
Go to Testing
for Intermittent
Conditions
and Poor
Connections
Go to Step 4
4
1. Turn the ignition OFF.
2. Disconnect the TCM from the J 39700 . Additional DTCs may set.
3. Turn ON the ignition, with the engine OFF.
4. Using the DMM, measure voltage at terminal 52 and ground.
Is the voltage greater than the specified value?
0 V
Go to Step 5
Go to Testing
for Intermittent
Conditions
and Poor
Connections