Pinpoint Test 3: Vehicle Does Not Shift Between 4WD High And 4WD Low Modes Correctly
TRANSFER CASE ELECTRONIC SHIFT PINPOINT TEST 3: VEHICLE DOES NOT SHIFT BETWEEN 4WD HIGH AND 4WD LOW MODES CORRECTLY
Normal Operation
The high-low shift occurs when the reduction shift fork moves the high-low collar to lock the planetary gear set to the output shaft. The torque transmitted through the sun gear from the input shaft turns the front planetary gear set assembly. The front planetary gear set assembly, now engaged, provides transfer case speed reduction. Certain criteria, such as vehicle speed and transaxle range selection must be met before this shift can occur. Systematically check the necessary inputs and outputs of the 4WD control module, components of the transfer case and halfshafts.
Possible Causes
- Transmission neutral switch
- ABS wheel speed inputs
- CAN communication network
