Transfer case Switching from 2H to 4H Intermittent

[WMU53]

Friday Sept.24: 349 kilometers of 2H to 4H - 4H Locked and 4 Low locked without an issue during an 8 hour day. Travelling through slick mud, water/mud holes, dust, dirt, bush along the North Saskatchewan river valley S and SE of Lodgepole Alberta. Using 4L locked to ease the brakes from overheating when descending steep hills.

Last upwards hill of egress at end of daylight allows switching off the 4H locked mode. Resume movement on trail and switch from 4H to 2H. The symbol on the dash flashes green continually. Attempt various scenarios to resolve without success. Drive home 120 kilometers with flashing green.

Saturday Sept.25: Raise suspension off ground. Confirm vehicle is in 2H. Pull 20Amp fuse for the ECU. Start vehicle. Locked symbol appears. Stop engine. Insert 20 amp fuse turn ignition to 2nd position without starting engine and the transfer case provides two audible mechanical cycles. This situation is repeatable but without corrective results. Clean area around electrical connector on transfer case. Remove connector. Looks clean but spray with electrical cleaner. Reinsert. At this time I notice the breather/vent hose is not connected due to rot! Repair and reinsert onto transfer case vent. Turn on ignition. Transfer case cycles and green flashing light is resolved. Lower vehicle on ground. Start engine. Flashing green returns. Repeat the wheels off ground process three times. Successfully clears then returns flashing. Remove console and selector switch. Switch is not faulty. I hear a clicking from the ECU, intermittently, when the problem occurs. Perform continuity test of wire harness from switch to ECU and from ECU harness to Transfer case . No issues. I have not checked for ECU voltages as it is late, cold and dark outside. Yeah. Life in Western Alberta. Haha.

Anyone care to chime in with experience or thoughts on this issue? I'm looking forward to your assistance-thoughts- etc.

Cheers! Eh!!

 

[hankd]

aren't the 4lo and locked lights amber and the downhill assist light green? did you accidentally hit the downhill assist button on the center console? that will cause a green flashing light on the dash i think.

 

[WMU53]

After having the time to research this topic it appears that without a hoist/lift and additional tools the job to replace the FAULTY actuator is best provided by a specialist. All due to a weeping vent hose.

Editing three days after the original post. After review of a service manual I tested the front diff actuator assembly. The unit is faulty. I went down the path of the transfer case actuator being the failed component as the unit would attempt ( I could audibly hear the shifting of the actuator rods ) to perform the required movement but without the front diff actuator responding the successful shift failed. Also the transfer case actuator vent hose had rotted off and I suspected failure due to water/grime contamination.

The repair cost will be 20% of the initial estimate.

 

[WMU53]

aren't the 4lo and locked lights amber and the downhill assist light green? did you accidentally hit the downhill assist button on the center console? that will cause a green flashing light on the dash i think.

Do believe you are correct on the lights but the problem is the defective actuator.

Repair is best handled by an automotive specialist with a lift and required tools for removal of the transfer case. Laying on the floor under the vehicle is not where I want to be.

Thanks for the input!

Cheers!