Info - Allison Transmission Control Module FastLearn Procedure Update Required After Transmission Repairs

This bulletin is being revised to change a labor operation number. Please discard Corporate Bulletin Number 02-07-30-032 (Section 07 -- Transmission/Transaxle).

A new "FastLearn" procedure has been released for the Allison 1000 Series™ Transmission. The "FastLearn" procedure must be completed any time the following vehicle repairs are performed:

The" FastLearn" procedure is a series of tests that are run to allow the Transmission Control Module (TCM) to "Learn" (Adapt) to the characteristics of the clutch packs within the transmission. As each clutch packs data is learned, "FastLearn" stores the information in the adaptive cells for each clutch within the TCM. "FastLearn" will allow a repaired Allison 1000 Series™ transmission to be road tested after completion of the repair in as near -fully-adapted state as possible. This will allow the technician and customer to drive the vehicle in the adapted mode and reduce the number of technician and customer concerns after a transmission repair. The "FastLearn" procedure consists of four (4) steps (modes).

Park Mode

While the transmission is in Park with the engine idling, FastLearn will cycle through a series of tests where the C3 and C4 clutches are repeatedly applied to learn their clutch characteristics. During the C3 and C4 clutch apply/release procedure, FastLearn is able to characterize the A and B solenoid pressures corresponding to clutch return springs, and is also able to learn the volumes for C3 and C4 clutch packs. In addition, C5 clutch is repeatedly applied and released in Park to purge out air for later learning of its clutch volume.

Drive Mode

Caution: While in Drive, if the Tech 2 loses communication, or becomes disconnected, the vehicle may remain in Drive and could move forward if the wheels have not been securely blocked.

Once all of the Park test data have converged, the Tech 2® instructs the driver to select Drive. Once Drive is selected, the TCM engages C1 clutch to obtain Drive and C1 clutch volume. The TCM repeats this test until the volume learned for C1 clutch has converged.

Reverse Mode

Caution: While in Reverse, if the Tech 2 loses communication, or becomes disconnected, the vehicle may remain in Reverse and could move backward if the wheels have not been securely blocked.

The Tech 2® will instruct the technician to select Reverse. When Reverse is selected, the TCM engages C5 clutch to obtain reverse and learn the C5 clutch volume. The TCM repeats this test until the C5 clutch volume has converged.

After learning C1 and C5 clutch volume, FastLearn updates the adaptive volume data for all shifts with either C1 or C5 on-coming clutch.

C2 Lean Mode

Following the Reverse Mode step, the Tech 2® exits "FastLearn" and the only adaptive cells that remain to be learned are the adaptive volume data for the C2 clutch. The vehicle must be driven for this procedure to be completed. The requirements for this step require the vehicle be driven long enough and far enough at a steady throttle at a speed where at least three (3), 3-4 upshifts occur, on the same ignition cycle. The TCM learns the adaptive learn for the C2 clutch by overfilling the C2 clutch and then reducing the overfill until C2 is corrected, C2 clutch volume is learned and all special "FastLearn" actions are completely disabled.

"FastLearn" Procedure

Important: The following conditions must be met before the "FastLearn" procedure can be performed:

Important: The Tech 2® software version must be 22.006, released in August 2002, or newer.

1. Firmly apply the park brake.
2. Connect the Tech 2® to the Vehicle ALDL Connector.
3. Turn the ignition key ON with the engine off.
4. Power up the Tech 2® by pressing the power key.
5. Is software version 22.006, or newer displayed on the Tech 2®? If not, you must go get it. If Yes, press the Enter key.
6. Select FO: Diagnostics.
7. Select: Model Year.
8. Select: Lt. Duty Truck.
9. Select F0: Powertrain.
10. Select: "The Proper Engine".
11. Select: "5 speed Automatic".
12. Select: the proper Emission Level, California or Federal.
13. Select F2: Special Functions
14. Select F1: Transmission Output Controls.
15. Press the up-arrow to select the : "Fast learn Adapt Process", Press Enter.
16. Follow the Instructions displayed on the Tech 2. You will notice the Transmission Fluid Temperature is displayed in a Bar graph at the top of the Tech 2 display screen.
17. When the Tech 2 states the Fast Learn has completed, Exit to the main menu.
18. Disconnect the Tech 2.
19. Drive the vehicle long enough and far enough at a steady throttle at a speed where at least three (3), 3-4 upshifts occur, on the same ignition cycle.

The technician should then verify the operating characteristics of the transmission and that transmission shift quality is acceptable before releasing the vehicle to the customer.

The following labor operation table is submitted for your use when servicing these vehicles under warranty. Each of the labor codes listed below will have an additional 0.4 hr added to the previously published time in the next labor time revision.