Pinpoint Test C: The Vehicle Does Not Shift Between 4H And 4L Modes Correctly

Pinpoint Test C: The Vehicle Does Not Shift Between 4H And 4L 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 transmission range selection, must be met before this shift can occur. Systematically check all inputs, related circuits and components. Often a blocked shift can occur when shifting to either 4H or 4L. This is due to misaligned gear teeth and can be considered normal on this transfer case. If the vehicle is not responding to the operator's intentions, try to move the transfer case lever with the vehicle moving at a speed below 5 km/h (3 mph). This will allow correct gear teeth alignment.

Possible Causes
- Transmission neutral drag torque
- Shift lever assembly
- Transfer case internal components

NOTE: If the transfer case shifts correctly with the engine off but does not shift correctly with the engine running and transmission in NEUTRAL, refer to Automatic Transmission/Transaxle to diagnose the transmission.