Test K: The Vehicle Does Not Shift Between 4X4 High and 4X4 Low Modes Correctly
Pinpoint Test K: The Vehicle Does Not Shift Between 4X4 High and 4X4 Low Modes CorrectlyNormal 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 transmission range selection, must be met before this shift can occur.
This pinpoint test is intended to diagnose the following:
^ Transmission neutral switch (or clutch pedal position [CPP] switch) - hardwired to the 4X4 control module
^ Brake ON/OFF (BOO) switch - hardwired to the 4X4 control module
^ ABS vehicle speed inputs - hardwired to the 4X4 control module
K1-K5:
K6-K8:
K8 (Continued)-K9:
