OPERATING RANGES
Transfer case operating ranges are
- Operating positions: 4WD Auto - N - 4WD Low.
- 4WD Auto = Electronically controlled wet clutch for torque biasing.
- N = Transfer case neutral for 4-wheel flat recreational towing.
- 4WD Low = Low range (2.72:1) part time mode.
The 4WD Low range is for off road use only. It is not for use on hard surface roads unless the road surface is wet, slippery, or covered by ice and snow.
The low range reduction gear system is operative in 4WD Low range only. This range is for extra pulling power in off road situations. Low range reduction ratio is 2.72:1.
ACTIVE TRANSFER CASE CONTROLS
Controls for the MP3023 transfer case active clutch (torque biasing device) are located in the Drive Train Control Module (DTCM) and communicated on the Controller Area Network (CAN) C bus. The DTCM monitors multiple vehicle sensors to anticipate conditions which may result in wheel slip or reduced performance and preemptively adjusts torque split to front and rear axles as needed. The DTCM also compares wheel speeds at the front and rear axles to detect wheel slippage. A complete vehicle dynamics model, or algorithm, calculates slip at each tire for given vehicle-operating conditions. When wheel slip is detected, pressure applied to the transfer case clutch pack can be increased or decreased to apply increased torque to the axle with higher traction.
TRANSFER CASE MODES
The transfer case operates in active full-time four-wheel drive (4WD AUTO) unless the driver chooses 4WD Low, or Neutral.
ELECTRIC SHIFT MECHANISM
The electronically controlled wet clutch pack uses an electric motor to actuate an internal gear train, clutch cam, and low range barrel cam. The clutch cam actuates the clutch levers that apply normal force to the multi-disc wet clutch pack. The clutch discs are alternately splined to the front and rear drive shafts. When normal force is applied to this clutch pack, torque is transferred to equalize speed differences between front and rear axles.
Transfer of torque from one wheel to the other on an axle is accomplished by using Brake Traction Control. Under the right conditions the vehicle can be driven by just one wheel.
ELECTRONIC STABILITY PROGRAM (ESP)
Standard Electronic Stability Program (ESP) works with the four-wheel drive system to enhance traction and control through three new features: Hill Descent, Hill Start Assist and Trailer Sway Control.
TRANSFER CASE - MP3023
| CONDITION | POSSIBLE CAUSE | CORRECTION |
|---|---|---|
| Transfer case difficult to shift or will not shift into desired range. | 1) Transfer case electronically controlled shift system malfunction. | 1) Check for Transfer Case DTCs. Refer to DIAGNOSIS AND TESTING and depending on vehicle configuration (FCM, FDCM, or DTCM), perform the appropriate diagnostic procedure and verification test. |
| 2) Insufficient or incorrect lubricant. | 2) Drain and refill transfer case with the correct quantity of Mopar® ATF +4. | |
| 3) Internal transfer case components binding, worn, or damaged. | 3) Repair or replace components as necessary. | |
| Transfer case noisy in all drive modes. | 1) Insufficient or incorrect lubricant. | 1) Drain and refill transfer case with the correct quantity of Mopar® ATF+4. |
| 2) Internal transfer case components binding, worn, or damaged. | 2) Repair or replace components as necessary. | |
| Transfer case noisy while in, or jumps out of, 4LO. | 1) Transfer case not completely engaged in 4LOW position. | 1) While rolling 2-3 MPH and the transmission in NEUTRAL shift the transfer case to the 4WD AUTO position, and then back into the 4LOW position. |
| 2) Range fork, input gear, or range sleeve damaged, inserts worn, or fork is binding on the shift rail. | 2) Repair or replace components as necessary. | |
| 3) Low range gear worn or damaged. | 3) Repair or replace components as necessary. | |
| Lubricant leaking from transfer case seals or vent. | 1) Transfer case overfilled. | 1) Drain lubricant to the correct level. |
| 2) Transfer case vent closed or restricted. | 2) Clean or replace vent as necessary. | |
| 3) Transfer case seals damaged or installed incorrectly. | 3) Replace suspect seals. Inspect and replace, if necessary, the seal slinger on the output flange associated with the damaged seal. |
DIAGNOSIS CHART
CLEANING
Clean the transfer case parts with a standard parts cleaning solvent. Remove all traces of sealer from the cases and retainers with a scraper and 3M™ all purpose cleaner. Use compressed air to remove solvent residue from oil feed passages in the case halves, retainers, gears, and shafts.