Allison Transmission 1000/2000 Operator`s Manual

Codes (DTCs), and to satisfy transmission feature/option requirements.

These shift inhibits fall within the following types:

• Above­idle neutral­to­range shifts

• Forward/reverse directional shifts

• Transmission problems

• Auxiliary equipment operation

3.12.1 Above­Idle Neutral­to­Range Shifts.

Above­idle (greater than 900 rpm in Allison 4 th

Generation transmissions, and greater than 1000 rpm in previous transmissions) shifts from N (Neutral) to R

(Reverse) or N (Neutral) to a forward range are normally inhibited (except in emergency vehicles or some other type of specialized equipment).

WARNING: To help avoid injury or property damage caused by sudden movement of the vehicle, do not make shifts from N (Neutral) to a forward range or R (Reverse) when the throttle is open. The vehicle will lurch forward or rearward and the transmission can be damaged. Avoid this condition by making shifts from N (Neutral) to a forward range or R (Reverse) only when the throttle is closed and service brakes are applied.

When these shifts are inhibited, the RANGE INHIBIT(ED) light illuminates.

See the

3.9 RANGE INHIBIT(ED) LIGHT

section in this manual for further information.

3.12.2 Forward/Reverse Directional Shifts.

Forward/reverse directional changes are typically not permitted if appreciable output shaft speed is detected.

WARNING: To help avoid injury or property damage caused by sudden movement of the vehicle, do not make shifts from N (Neutral) to a forward range or R (Reverse) when the throttle is open. The vehicle will lurch forward or rearward and the transmission can be damaged. Avoid this condition by making shifts from N (Neutral) to a forward range or R (Reverse) only when the throttle is closed and service brakes are applied.

When these shifts are inhibited, the RANGE INHIBIT(ED) light illuminates.

See the

3.9 RANGE INHIBIT(ED) LIGHT

section in this manual for further information.

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