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• Sleep Mode will be entered, from the Reduced Power Mode, when no PCI traffic has been sensed for SHIFT REQUIREMENTS If the TCCM is in full power mode and at function- ality level zero, it uses the following criteria to deter- Mode shifts will be allowed regardless of trans- mission gear or vehicle speed, whenever the following • 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 TCCM. • Proper transmit/receive messages are occurring on the PCI bus. • Ignition key switch is in the RUN position. lowing conditions are met: • A change in the Selector Switch state indicating a range shift has been requested. • Transmission in NEUTRAL signal must be rec- ognized for at least 1.5 seconds ±100 msec. • Proper transmit/receive messages are occurring on the PCI bus. • Clutch signal is recognized for 500 msec ± 50 msec (Clutch pedal depressed if a manual transmis- • Vehicle speed is less than or equal to 4.8 km/hr (3 miles per hour). • Ignition key switch is in the RUN position. • A valid mode sensor signal is being sensed by the TCCM. A shift into transfer case Neutral will be allowed only if all of the following conditions are met: • The recessed Neutral Selection switch has been depressed continuously for 4.0 seconds ±100 msec • Transmission in NEUTRAL signal recognized from the bus. • Clutch signal is recognized from the bus (Clutch pedal depressed if a manual transmission). • Proper message transmissions/receptions are occurring on the PCI bus. • Vehicle speed is less than or equal to 4.8 km/hr (3 miles per hour). • Ignition key switch is in the RUN position, engine off. • Foot Brake is applied. • A valid mode sensor signal is being sensed by the TCCM. A shift out of transfer case Neutral will be allowed only if all of the following conditions are met: • The recessed Neutral Selection switch has been depressed continuously for 1.0 seconds ±100 msec • Transmission in NEUTRAL signal recognized from the bus. • Clutch signal is recognized from the bus (Clutch pedal depressed if a manual transmission). • Proper message transmissions/receptions are occurring on the PCI bus. • Vehicle speed is less than or equal to 4.8 km/hr (3 miles per hour). • Ignition key switch is in the RUN position, engine off. • Foot Brake is applied. • A valid mode sensor signal is being sensed by the TCCM. SHIFT SEQUENCES Once all the driver controllable conditions for the requested shift have been met, the TCCM begins a RANGE AND MODE SHIFTS The process for performing all the range and mode shifts are the same. The following steps describe the • Allow time for Selector Switch debounce; 250 msec ±50 msec. • Perform diagnostics on the motor that will check for opens/shorts. • Engage the shift motor for a maximum of 1 sec- ond ±100 msec per ’D’ channel transition in the des- • Transmit a bus message that a transfer case shift is in progress. • Disengage the shift motor when the correct mode sensor code is recognized. • Solidly illuminate the current transfer case posi- tion’s LED while extinguishing the source gear’s • Transmit a bus message that the transfer case shift is complete. • If the desired mode sensor code is not received after the shift timer expires (ie. a blocked or other 8E - 22 ELECTRONIC CONTROL MODULES AN TRANSFER CASE CONTROL MODULE (Continued) |