Range Inhibit Indicator, 2000 Series Transmissions

wv dm 7.02.003

A RANGE INHIBIT indicator is a standard feature of the 2000 series transmissions. The RANGE INHIBIT indicator comes on to alert the driver that transmission operation is being inhibited and that the range shifts being requested by the driver may not occur. When certain operating conditions are detected by the transmission control module (TCM), the controls will lock the transmission in the current operating range.

Shift inhibits occur under the following conditions:

  • Shifts from Neutral (N) to Reverse (R) or from Neutral (N) to a forward range when the engine is above idle, greater than 900 rpm.

  • Forward/Reverse (R) directional shifts are typically not permitted if appreciable output shaft speed is detected.

  • When some types of unusual transmission operating conditions are detected by the TCM, the TCM temporarily limits transmission operation until the vehicle can be driven to a service location. When this type of situation is detected, the TCM will lock the transmission in a safe gear range.

Note:
Parent topic: Allison Automatic Transmissions
Document Number: 0000071427
Manual Publication Date: 2024-03-26
Topic Publication Date: 2024-03-26