WORKHORSE CUSTOM CHASSIS
Service Manual
2007 W Series
SECTION
7.2
PAGE
136
Automatic Transmission – Allison
2007 W Series Chassis
© 2006 Workhorse Custom Chassis — All Rights Reserved
WSM082106
DTC P0659
Step
Action
Value
Yes
No
5
1. Connect the AT inline 20-way connector.
2. Remove the transmission oil pan. Refer to Oil Pan Replacement
.
3. Remove the connectors to PCS1, MAIN MOD and TCC sole-
noids.
4. Using the DMM measure the supply voltage of each solenoid
connector.
Is the voltage greater than the specified value?
6 V
Go to Step 7
Go to Diagnostic Aids
6
Test the high side driver circuit between the TCM and 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 10
—
7
Replace the AT internal wiring harness. Refer to Wiring Harness
Replacement.
Did you complete the replacement?
—
Go to Step 10
—
8
IMPORTANT:
In most cases, the TCM is not at fault. Investigate thor-
In most cases, the TCM is not at fault. Investigate thor-
oughly before replacing the TCM.
oughly before replacing the TCM.
Replace the TCM. Refer to Control Module References for replacement,
setup, and programming.
Did you complete the replacement?
—
Go to Step 10
—
9
Perform the following procedure in order to verify the repair:
1. Clear the DTC.
2. Start the engine.
3. Select Specific DTC.
4. Enter DTC P0659.
Has the test run and passed?
—
Go to Step 10
Go to Step 2
10
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