WORKHORSE CUSTOM CHASSIS
Service Manual
2007 W Series
SECTION
7.2
PAGE
366
Automatic Transmission – Allison
2007 W Series Chassis
© 2006 Workhorse Custom Chassis — All Rights Reserved
WSM082106
DTC P0974
Step
Action
Value
Yes
No
5
1. Turn the ignition OFF.
2. Disconnect the AT inline 20-way connector. Additional DTCs may
set.
3. Install the J 44152 jumper harness (20 pins) on the engine side of
the AT inline 20-way connector.
4. Turn ON the ignition, with the engine OFF.
5. Using the DMM and the J 35616 GM terminal test kit, measure for
voltage at terminal A and ground of the J 44152 . Refer to Automatic
Transmission Inline Harness Connector End View .
Is the voltage greater than the specified value?
0 V
Go to Step 8
Go to Step 6
6
1. Connect the AT inline 20-way connector.
2. Remove the transmission oil pan. Refer to Oil Pan Replacement .
3. Remove the AT internal wiring harness at the SS1 connector.
4. Using the DMM, measure for voltage at terminal B of SS1 and
ground.
Is the voltage greater than the specified value?
0 V
Go to Step 9
Go to Step 7
7
1. Disconnect SS1 from the internal wiring harness.
2. Using the DMM, measure SS1 resistance.
Is resistance within the specified value?
22.0 ohms at 20°C
(68°F)
Go to Testing
for Intermittent
Conditions
and Poor
Connections
Go to Step 10
8
Test the SS1 circuit between the TCM and the AT inline 20-way connector
for a short to voltage. Refer to Testing for a Short to Voltage .
Did you find and correct the condition?
—
Go to Step 11
—
9
Replace the AT internal wiring harness. Refer to Wiring Harness
Replacement .
Did you complete the replacement?
—
Go to Step 11
—
10
Replace the SS1. Refer to Control Valve Solenoid Replacement .
Did you complete the replacement?
—
Go to Step 11
—