Gen 2 - How bad is it to drive with faulty IWE actuator(s)?

[dsiggi]

I've had this twice on my 2018 , both in cold weather, intermittent as you describe above and coming to a stop. Both times on the drivers side. Both times the dealer replaced my IWE and the sound went away. Why just the drivers side each time? Good question, I sure would like to know. I'm happy to have it fixed but wish I had more info on root cause etc.

Usually happened after some hard offroading in snow, fwiw. Sometimes deeper snow and sometimes just scrapped roads but running a little harder in 4wd High.

Haven't had it in a couple of years now. Not sure if the IWE's are better or I'm just lucky. I was getting used to the fact once I'm out ESP this will be a regular occurrence. I was hoping it could be something besides the actual IWE itself, but thats been the fix the 2 times I had the concern.

 

[FordTechOne]

I've had this twice on my 2018 , both in cold weather, intermittent as you describe above and coming to a stop. Both times on the drivers side. Both times the dealer replaced my IWE and the sound went away. Why just the drivers side each time? Good question, I sure would like to know. I'm happy to have it fixed but wish I had more info on root cause etc.

Usually happened after some hard offroading in snow, fwiw. Sometimes deeper snow and sometimes just scrapped roads but running a little harder in 4wd High.

Haven't had it in a couple of years now. Not sure if the IWE's are better or I'm just lucky. I was getting used to the fact once I'm out ESP this will be a regular occurrence. I was hoping it could be something besides the actual IWE itself, but thats been the fix the 2 times I had the concern.

Sounds like a workmanship issue. The IWE install procedure is critical to it working properly. The system is basic vacuum; if they are dragging/engaging when they are not supposed to there is loss/lack of vacuum to the diaphragm(s).

 

[dsiggi]

I agree with you on the way the system works, but how is it producing the issue, the dealer fixing with new IWE, problem goes away, then another year later or so after being in deep snow wheeling it hard, it coming back a workmanship issue? The thing thats interesting to me is its on slowing from like 10 mph to stop. I assume thats when the motor is making the least amount of vaccuum?

 

[FordTechOne]

I agree with you on the way the system works, but how is it producing the issue, the dealer fixing with new IWE, problem goes away, then another year later or so after being in deep snow wheeling it hard, it coming back a workmanship issue? The thing thats interesting to me is its on slowing from like 10 mph to stop. I assume thats when the motor is making the least amount of vaccuum?

Because it will only last so long if it’s installed improperly. That could be a week, that could be a year. Insufficient vacuum will also cause repeat IWE failure as well.

 

[dsiggi]

Because it will only last so long if it’s installed improperly. That could be a week, that could be a year. Insufficient vacuum will also cause repeat IWE failure as well.

Thats interesting, how would you even install it improperly?

 

[Rptrrob702]

@dsiggi Was it the actual IWE hub actuator they replaced? Exact same thing happening on the driver side only. I'm probably going to buy a hand vacuum pump and diagnose it myself this evening. Was hoping it would just be the solenoid.

 

[dsiggi]

@dsiggi Was it the actual IWE hub actuator they replaced? Exact same thing happening on the driver side only. I'm probably going to buy a hand vacuum pump and diagnose it myself this evening. Was hoping it would just be the solenoid.

I'd be interested to see what you come up with. They replaced both the solenoid and the hub actuator each time. They said in the diagnostics the hub actuator didnt make spec vacuum even with the new solenoid. Part of me wants to believe there is a simpler fix and they just missed it and threw parts at it, but I never put a vacuum gauge on it and did the diag myself. Thought maybe the line running to the hub actuator may have been compromised so in the freezing cold I tried to wiggle that around a bit with no avail, but since I didnt have a hoist or heated space to mess with it anymore I just took to and had it done under my ESP.

 

[dsiggi]

Welcome to FRF. Pictures, or it’s a prius.


I’ll bet it doesn’t do it when it’s cold either. Because that’s apparently a reprogram Ford did a while back; it locks the hubs until up to temp ...ish.

Have you tried replacing the solenoid? It’s like 7 bucks off amazon. Maybe 9 bucks now, but easy to replace, accessible, inexpensive and is the most common ‘wear’ part in the system as I understand it.

IWE works in that it needs vacuum to keep the truck in 2h, unlocking the front hubs. This way it “fails over” to hubs locked so you can engage 4a, 4h and presumably 4L.

when there is insufficient vacuum you’ll get an incomplete disengagement in 2h. The damage to the IWE hard parts comes in when you don’t do anything to avoid the problem. You’re on here trying not to do that, so, likely you’re not at risk there if it hasn’t been observed for long.

1) 4A. Learn it. Live it. Love it. Be warned, it’s addictive. You can be a lot less judicious with the throttle in 4a and get away with it. This setting works around the issue.
2) pick up a solenoid off amazon or wherever. swap it yourself and see if it goes away.
3) if 2 doesn’t pan out, see #3.

@FordTechOne has forgotten more about the IWE system than most of us here know. He’s also shown a ... slight disdain, shall we say, for poor troubleshooting and workmanship exhibited by some stories told here. I don’t remember exactly but I think someone posted a schematic of the IWE system, it’s pretty darn clever. But, it does have some wear items to keep on top of.

You should be fine in the short term.

Whats this reprogram you speak of for cold and being up to temp. Mine always exhibited the issue when it was cold only if i remember correctly.

 

[FordTechOne]

Thats interesting, how would you even install it improperly?

The IWE needs to be fully retracted with a vacuum pump during installation and the depth of the CV axle shaft needs to be measured to verify its fully seated.

 

[FordTechOne]

Whats this reprogram you speak of for cold and being up to temp. Mine always exhibited the issue when it was cold only if i remember correctly.

2019 models introduced a new strategy that keeps the IWEs engaged when the truck is first started and driven to allow the system to warm up and the engine to build sufficient vacuum before disengagement. The TSB includes the update for 2017-2018 models.