WORKHORSE CUSTOM CHASSIS
Service Manual
Automatic Transmission – Allison
2007 W Series
© 2006 Workhorse Custom Chassis — All Rights Reserved
SECTION
7.2
PAGE
449
2007 W Series Chassis
WSM082106
sump temperature. Any active special function, such
as anti-lock brakes or power take-off, is also an input
to the TCM. The TCM processes this data to determine
proper shift points, to monitor the current range, to
perform ratio tests, and to compile diagnostic data. The
TCM is programmed to protect the transmission and
other vehicle driveline components by inhibiting actions,
such as full-throttle NEUTRAL-to-range shifts and high-
speed direction changes. The TCM determines if a
system malfunction exists and stores diagnostic codes
related to the malfunction. The codes accessed by the
service technician are used in diagnosing persistent or
intermittent trouble in the system.
To obtain transmission diagnostic trouble codes (DTCs),
install the scan tool and follow the menu selections listed
below:
1. From the title screen, press ENTER.
2. Select F0: Diagnostics. Press ENTER.
3. Select Model Year, i.e. (6) 2006. Press ENTER.
4. Select Workhorse. Press ENTER.
5. Select Product Make, i.e. (C) Chevrolet Truck, (T)
GMC Truck. Press ENTER.
6. Select Product Line, i.e. (C) or (K). Press ENTER.
7. Select F0: Powertrain. Press ENTER.
8. Select Engine size, i.e. (G) 8.1L V8 L18. Press
ENTER.
9. Select 6 Speed Automatic. Press ENTER.
10. Select F0: Diagnostic Trouble Codes (DTC). Press
ENTER.
11. Select F1: DTC (s) (Transmission). Press ENTER.
12. Select F0: DTC Information. Press ENTER.
13. Select F0: DTC Info. Press ENTER.
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 refer-
record the Freeze Frame and Failure Records for refer-
ence. The Clear Info function will erase the data.
ence. The Clear Info function will erase the data.
CLUTCH TEST
Clutch Test allows a technician to manually select each
of the 6 forward ranges with the vehicle stopped. The
intent of this procedure is to verify the ability of all 5
clutches to transmit torque without slipping. Refer to
the table in Adapt Function , which shows the clutches
applied in each gear range.
Clutch Test
Use the scan tool in order to perform the clutch test.
Select the following information when setting up the tool
for running the test. Use the Shift Transmission feature
on the scan tool to complete the clutch test.
1. Select F0: Diagnostics and press ENTER.
2. Select Model Year, i.e. 6 (2006).
3. Select LDTrk, MPV, Incomplete.
4. Select F0: Powertrain, press ENTER.
5. Select Engine size, i.e. (G) 8.1L V8 L18, press
ENTER.
6. Select 6 Speed Automatic, press ENTER.
7. Select F2: Special Functions, press ENTER.
8. Select F1: Transmission Output Controls.
9. Select Shift Transmission. This allows the technician
