Front Axle actuator engages by itself when truck is in 2WD

[q1werty2]

I'm sure this has been discussed but I am unable to locate a thread on it. Below is my issue along with some other "side symptoms". I have no idea if they are related.

History - "4WD Shift in Progress" message displays intermittently. This has been happening for two years. I took it in under warranty and the dealer was unable to find out what the issue is and told me not to worry about it. They re-flashed it, but no change. There has been no issues with this message and 4x4 has worked as expected. I just learned to live with the message.

December 23rd - the ESC light comes on while driving on the interstate from Texas to Alabama. I figured it is a bad wheel sensor and will deal with it later. As usual, the "4WD Shift in Progress" message comes on and off throughout the trip.

December 25th. "4WD Shift in Progress" message comes on, but this time it is accompanied by the "4x4" orange light indicating the truck THINKS it is in 4WD. After moving about 100 feet I heard a loud grinding noise followed by a loud pop from front of truck. I was driving about 10 mph when this happened. I stop and play with/jiggle the 4WD shifter and the light goes off. I drive it to where I am staying for the holidays with no issue.

Next morning the exact thing happens in the driveway so I take it to my brother's house for inspection. It appears the front actuator is engaging by itself even when the 4WD lever is in 2WD. When I played with the 4WD shift lever (just jiggled it) the 4WD light would come on and off. When the light was on, the ESC light went off. When the light was off, the ESC light came on. I am making no correlation between the 4WD and ESC lights as it seems ESC would be disabled any way in 4WD. Just stating what I observed.

I unplugged the connector from the front axle actuator and the truck drives fine. I even put it up on jack stands to make sure it was really in 2WD, and it is. I have the "SERV 4WD" light on, which is expected with the connector unplugged.

December 31 - drove back home to Texas with no issues. ESC light is still on. SERV 4WD light is still on. "4WD Shift in Progress" light is no longer happening (I'm guessing because the front actuator is unplugged)

Please note - I have an actual lever on the floor to select 4WD mode. I do not have a knob on the dash or an actuator (plunger) on the transfer case. There is no way for the transfer case to be engaged unless I physically move the 4WD shift lever. Just adding that in here so no one suggests I have a bad selector knob/switch. My truck does not have the knob on the dash.

The only think I can think of is that there is a sensor somewhere that is bad, but I sure as heck can't find it.

Recap - Front axle actuator engages by itself, even when shift lever is in 2WD position.
Current State: Front axle actuator is unplugged, and will remain so until I figure out what the fix is.

Any help from the forum would be greatly appreciated.

Truck info:
2014 2500 Tradesman (base model)
84,000 miles
100% stock except for wheels/tires which are same size as originals

Thanks in advance,
Scott W.

 

[Brandon-w]

You wouldn't be able To tell me the model your t case is would you? Should be a sticker on it. I want to look it up and see if there is a sensor on it. If there is not I would guess it's your 4x4 Control module located right under your glove box on the firewall directly behind your blower motor.

 

[q1werty2]

Thanks for the reply. The model is BW 44-47. I did some more digging last night and found a switch that supposedly sends a signal if is it is 2WD or 4WD. Part number for that switch is 68211454AA.

Trying to find specs on how to test it at the moment. It's cheap enough that I may just take the gamble and throw a new one in.

Thanks,
Scott

 

[Zack02]

Scott, I had this issue. Literally the same truck. It's the sensor, not the controller. There's a sensor under the shifter; you will need a LARGE socket, like 35 mm, just swap it out and you will be good to go. I wish I had read your second post, but yes, it's Mopar #68211454AA. Mine was like $50 shipped.

Hope it helps.

 

[q1werty2]

Thanks! - I ordered the part and it should be here tomorrow. I will post the results here either way once I have it in.

 

[CVX20]

Thanks! - I ordered the part and it should be here tomorrow. I will post the results here either way once I have it in.

If you want to test first you could just unplug it.It is a normally open switch when in 2wd and then they stick closed when defective making the frt axle think it's in 4wd.

 

[q1werty2]

My apologies for the delay. I hate it when people never come back and explain the fix, so here it is.

The part (68211454AA) fixed it. When I removed it the plunger was recessed (retracted into the housing) rather than in the "protruded" position. I could easily pull the plunger out with a pair of pliers, but it would be slowly pulled back in by the magnetic assist. I have attached a photo comparing the old and new. Old is on bottom.

Note: Before I had fixed this I had disconnected the front axle actuator. I did this so I could get back home as it was constantly trying to engage. The day before I replaced the switch, the back wheels "locked-up" when I turned and the dash was flashing 4x4 lo. I am assuming the ESC engaged as it was thinking one wheel was slipping. By locked-up I mean that the inside wheel was hopping and trying to keep up with the outside wheel.

Regarding the test mentioned in the post above - I unplugged the connector from the switch, and plugged the front actuator back in and started the truck. The 4x4 light no longer flashed, but the "SERV 4WD" light was illuminated. Therefore, I am guessing one of the wires on the switch is a signal wire.

Tip - You are going to need a 90 degree pick to get the connector off the switch. The clip is away from the easy access side and a little tough to get to. I used a 1.5" socket and a 1/2 drive with a short handle. Be careful not to break the plastic connector when installing.
Also - don't forget the O-ring.

Opinion - this switch is engineered exactly opposite of what it should be. When a switch like this fails it should revert back to a "steady" state. In this case, a failed switch engages the front actuator and can even start applying brakes to the rear wheels in a turn.


Anyway - problem solved. All warning lights are out and the truck is shifting into and out of 4x4 hi and low perfectly.

 

[IMBuckhorn]

I’m having similar issues. The 4wd shift in progress flashes intermittently while I’m driving. I have a 2016 3500 tradesmen twin turbo. Is this the correct part number number for me?

 

[AGRam]

This just started happening on my 2019 PW. And I’m taking it on a 3300 mile road-trip in a week… better order a shift lever sensor asap.