WORKHORSE CUSTOM CHASSIS
Service Manual
2007 W Series
SECTION
7.2
PAGE
240
Automatic Transmission – Allison
2007 W Series Chassis
© 2006 Workhorse Custom Chassis — All Rights Reserved
WSM082106
DTC P0757
Step
Action
Yes
No
6
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 J 35616 GM terminal test kit and a fused jumper wire, connect termi-
nal F of the J 44152 to ground. Refer to Automatic Transmission Inline Harness
Connector End View.
Does the scan tool indicate PS2 status is LOW when grounded and HIGH when open?
Go to Step 7
Go to Step 14
7
1. Connect the AT inline 20-way connector.
2. Remove the transmission oil pan. Refer to Oil Pan Replacement.
3. Disconnect the AT internal wiring harness from the PSM and ground terminal B.
Does the scan tool indicate PS2 status is LOW when grounded and HIGH when open?
Go to Step 8
Go to Step 13
8
1. Remove the PSM from the control valve body and leave the internal harness
connected. Refer to Pressure Switch Manifold Replacement .
2. Provide a ground connection for the PSM to either the control valve body or the
transmission main case.
3. Using the eraser end of a pencil, push gently on the PS2 membrane.
Does the scan tool indicate PS2 status is LOW when grounded and HIGH when open?
Go to Step 9
Go to Step 12
9
Remove the control valve body and inspect for a stuck or sticking SS2. Refer to
Control Valve Body Disassemble .
Was the SS2 stuck or sticking?
Go to Step 11
Go to Step 10
10
Replace the SS2 and install the control valve body. Refer to Control Valve Body
Replacement .
Did you replace the solenoid and install the valve body?
Go to Step 16
—
11
Clean and/or polish the sticking valve in order to restore free movement or replace the
control valve body assembly. Refer to Control Valve Body Cleaning and Inspection .
Was free movement restored or the valve body replaced?
Go to Step 16
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