Shift Requirements
If the FCM is in full power mode and at functionality level zero, it uses the following criteria to determine if a shift is allowed.
If any of the driver controllable conditions are not met once the shift request is recognized, the FCM may illuminate one or more of the 4WD system message icons in the instrument cluster display.
Mode shifts will be allowed regardless of transmission gear or vehicle speed, whenever the following conditions are met:
- Ignition key switch is in the RUN position.
- Front and rear wheel speed are within 21 km/hr (13 mph).
- A change in the Selector switch state indicates that a mode shift has been requested.
- A valid mode sensor signal is being sensed by the FCM.
- Proper transmit/receive messages are occurring on the CAN bus.
- An Anti-lock Brake System (ABS) event is not in progress.
Range shifts will be allowed only if all of the following conditions are met:
- Ignition key switch is in the RUN position.
- Front and rear wheel speed are within 21 km/hr (13 mph).
- A change in the Selector Switch state indicating a range shift has been requested.
- Transmission in NEUTRAL signal must be recognized for at least 1.5 seconds +/-100 msec. (Automatic transmissions only)
- Proper transmit/receive messages are occurring on the CAN bus.
- Clutch signal is recognized for 500 msec +/- 50 msec (Manual transmissions only).
- Vehicle speed is less than or equal to 4.8 km/hr (3 miles per hour).
- A valid mode sensor signal is being sensed by the FCM.
- An Anti-lock Brake System (ABS) event is not in progress.
A shift into transfer case Neutral will be allowed only if all of the following conditions are met:
- Ignition key switch is in the RUN position, engine off.
- Front and rear wheel speed are within 21 km/hr (13 mph).
- The recessed Neutral Selection switch has been depressed continuously for 4.0 seconds +/-100 msec while all shift conditions have been continuously met.
- Transmission in NEUTRAL signal recognized from the bus. (Automatic transmissions only)
- Clutch signal is recognized from the bus (Manual transmissions only).
- Proper message transmissions/receptions are occurring on the CAN bus.
- Vehicle speed is less than or equal to 4.8 km/hr (3 miles per hour).
- Foot Brake is applied.
- A valid mode sensor signal is being sensed by the FCM.
- An Anti-lock Brake System (ABS) event is not in progress.
A shift out of transfer case Neutral will be allowed only if all of the following conditions are met:
- Ignition key switch is in the RUN position.
- Front and rear wheel speed are within 21 km/hr (13 mph).
- The recessed Neutral Selection switch has been depressed continuously for 1.0 seconds +/-100 msec while all shift conditions have been continuously met.
- Transmission in NEUTRAL signal recognized from the bus. (Automatic transmissions only)
- Clutch signal is recognized from the bus (Manual transmissions only).
- Proper message transmissions/receptions are occurring on the CAN bus.
- Vehicle speed is less than or equal to 4.8 km/hr (3 miles per hour).
- A valid mode sensor signal is being sensed by the FCM.
- An Anti-lock Brake System (ABS) event is not in progress.