METHOD AND SYSTEM FOR CONTROLLING A TWO-SPEED TRANSFER CASE
A transfer case control system for a vehicle which includes a transfer case has a mode-selection solenoid, a range-selection solenoid, a control module, a plurality of data inputs, and a plurality of selector switches. The mode-selection solenoid is constructed and arranged to effect a mode change via the transfer case. The range-selection solenoid is constructed and arranged to effect a range change via the transfer case. The control module is electronically coupled to the pair of solenoids and to the plurality of data inputs and to the plurality of selector switches. The plurality of selector switches are actuatable by the vehicle operator and include indicating lamps which provide a visual indication of transfer case status as well as a visual alert to the vehicle operator when a selected operation is not allowed.
1 . In combination:
a transfer case constructed and arranged to operate based on gear engagement; and
a transfer case control system for a vehicle which includes the transfer case, said transfer case control system comprising:
a mode-selection solenoid constructed and arranged to effect a mode change via said transfer case;
a range-selection solenoid constructed and arranged to effect a range change via said transfer case;
a control module electronically coupled to said mode-selection solenoid and to said range-selection solenoid;
a plurality of data inputs electronically coupled to said control module; and
a plurality of selector switches actuatable by a vehicle operator, said plurality of selector switches including indicating means for providing a visual indication of transfer case status and a visual alert to the vehicle operator when a selected operation is not allowed, wherein a specific set of data inputs is required in order for the transfer case control system to allow said selected operation.
2 . The combination of claim 1 wherein said plurality of data inputs include an input from a J1939 communications network which is a portion of vehicle electronics.
3 . The combination of claim 1 wherein said plurality of data inputs include data from a transfer case ratio indicator switch, a front axle indicator switch, a front axle selector switch, and a transfer case selector switch.
4 . The combination of claim 1 wherein selectable mode options include engaged and disengaged relative to a front drive axle of said vehicle.
5 . The combination of claim 4 wherein said engage mode is permitted by said control module only when specific conditions are satisfied, one of said specific conditions being a vehicle speed below a specified limit.
6 . The combination of claim 5 wherein said specified limit is approximately 10 miles per hour.
7 . The combination of claim 6 wherein said vehicle speed is provided by a J1939 communications network.
8 . The combination of claim 4 wherein a disengage mode results from a speed default setting.
9 . The combination of claim 8 wherein said default setting speed is set at approximately 25 miles per hour.
10 . The combination of claim 4 wherein one selector switch corresponds to said selectable mode options.
11 . The combination of claim 10 wherein said one selector switch includes an indicator lamp corresponding to each selectable mode option.
12 . The combination of claim 1 wherein said range options include HIGH and LOW wherein said HIGH range has an associated gearing ratio and said LOW range has an associated gearing ratio.
13 . The combination of claim 12 wherein said HIGH range option requires a NEUTRAL transmission status for the selection to be permitted by said transfer case control system.
14 . The combination of claim 12 wherein said LOW range option requires a NEUTRAL transmission status for the selection to be permitted by said transfer case control system.
15 . A transfer case control system for controlling mode and range of a vehicle transfer case, said transfer case control system comprising:
a mode-selection solenoid operable to engage or disengage a drive axle via said vehicle transfer case;
a range-selection solenoid operable to effect a range selection of either HIGH range or LOW range to be effected via said vehicle transfer case;
a control module electronically coupled to said mode-selection solenoid and to said range-selection solenoid;
a plurality of data inputs electronically coupled to said control module; and
a plurality of selector switches actuatable by a vehicle operator, said plurality of selector switches including indicating means for providing a visual indication of transfer case status and a visual alert to the vehicle operator when a selected operation is not allowed, wherein a specific set of data inputs is required in order for the transfer case control system to allow said selected operation.
16 . The transfer case control system of claim 15 wherein said plurality of data inputs include an input from a J1939 communications network which is a portion of vehicle electronics.
17 . The transfer case control system of claim 15 wherein said plurality of data inputs include data from a transfer case ratio indicator switch, a front axle indicator switch, a front axle selector switch, and a transfer case selector switch.
18 . The transfer case control system of claim 15 wherein said disengage mode results from a speed default setting.
19 . The transfer case control system of claim 18 wherein said default setting speed is set at approximately 25 miles per hour.
20 . The transfer case control system of claim 15 wherein said HIGH range option requires a NEUTRAL transmission status for the selection to be permitted by said transfer case control system.
21 . The transfer case control system of claim 15 wherein said LOW range option requires a NEUTRAL transmission status for the selection to be permitted by said transfer case control system.
22 . A method of controlling a transfer case which is a part of a vehicle drive system, said vehicle drive system including an electronics package and a pair of selector switches accessible to a vehicle operator, said method of controlling including the following steps:
a.) engaging a control switch to select 4WD;
b.) monitoring a signal lamp to assess the status of the 4WD selection;
c.) verifying that the vehicle is in 4WD mode;
d.) engaging a control switch to select a LOW gear ratio; and
e.) monitoring a signal lamp to assess the status of the LOW gear ratio selection.