Seems to me that the haldex clutch isn't doing its job. On mine I removed the drive shaft, the rear axles and kept the clutch/diff in place. ABS still works great. It behaves like your description. Maybe one difference, if I drive some small mileage after the 4wd light is on, it goes off if there is no more slippage.

 

There are about 10 possible codes that can be set by issues, even if the CEL isn't on, can you check for codes?

 

Any fault codes wouldn't be in the PCM, they'd be elsewhere and would never turn on the CEL.

 

You can still get them. I disconnected the harness to the rear diff in my 2012 Fusion AWD and it set a body (Bxxxxx) and a module (Uxxxxx:xx) code, that I was able to read with a $4 bluetooth OBDII adapter and Torque on my phone and/or Forscan on a laptop. I don't even think I needed the MS-CAN/HS-CAN switch, just a regular adapter. I might have had to use Forscan and select the module, but I don't think so.

 

You will still read them via the OBDII connector, but they're not coming from the the PCM. AWD codes will come from the ITCC module.

 

Thanks everyone. My buddy has a professional scanner and I'm going to drive by Saturday to have him scan it. I'll post the codes.

John

 

In the meantime, I see that PTUs are somewhat troublesome in these cars. I had to change my wife's PTU in her Edge (similar but bigger) because it was making a freaking racket, but never broke internally. Are the Escape PTUs known to physically break inside and cause a disconnect to the rear?

I was thinking about jacking up just the front of the truck and seeing if the driveshaft is turning going into the rear diff to tests the PTU and intermediate shaft.

John

 

Other than you probably have a drain plug, yes, these PTUs are problematic. They hold a small amount of gear oil, and I don't think the fluid is ever considered in the maintenance schedule.

The PTU in my Fusion was pushing out some very smelly gooey black garbage. I don't have a drain, so I overfilled it with fresh gear oil, drove it around, sucked out what I could and refilled it, and did that twice. No more gunk out the vent, and I am pretty sure it has enough oil in it. It was never noisy.

While I don't think this is an "overheat" condition, there isn't actually a way to measure temps any place, it has to be derived it seems. I think that it uses amount of slip. It also initially locks 100% when overheat condition, then 0% until it enough time passes and the key is cycled.

 

My buddy just left. No codes in the 4WD or ABS modules.

I'm going to try jacking up the front and watching what the driveshaft does when the front wheels spin.

Do these PTUs have chains in them or are they otherwise known to fail and disconnect power? How about the intermediate shaft that connects the trans to the PTU? Any chance these will strip out?

John

 

The PTU is similar to a rear diff, a ring gear and a pinion like thing. Other than bearings and seals, nothing else. They just constantly take power and turn it 90 degrees out the back to the driveshaft to the rear differential (to the locking mechanism, that is what is controlled to transfer a specified amount of power to the rear).

 

The PTU on the 2005 does have separate fill and drain plugs. I refilled mine at about 70K km, as there was a little leak (can tell from the smell) but the fluid looked good, so just a refill operation. I used a squeeze bottle and a soft tube to reach the fill plug. Years later I see smelly drops again, so a refill is on the to-do list but with a thread sealer on the drain plug this time.
Ford Maculoco shows the inside of a PTU.

 

I jacked up the front of the Tribute and put it in gear. The front wheels turn but the driveshaft doesn't - something mechanical is broken either in the PTU or the transaxle..

End of the road for the Tribble - we had a pretty good run. I honestly thought the transmission would have been the death knell.

John

 

Maybe I don't figure correctly what you described. With the engine running it would be dangerous to do that, without the four wheels up, given a possible malfunction of the drive system. If you turned the wheels manually, there may be a differential function that prevents the drive shaft to turn while the front wheels turn each in an opposite direction. iirc the power to the ptu is from a concentric shaft (somehow connected to the planetary) around the right front axle within the transmission.

I suggest that you raise the four wheels up and try again. On mine the haldex was stuck at the "engaged" position, so if I jammed one rear wheel, turning the other one made the drive shaft turn. With the tranny at park or neutral.

Given the residual value, and the state of the rest of the car, it may be tempting to let it go. If there is no oils or other liquids going out from the ptu, you can do as I did. Take off the drive shaft, cut off the rear axles and you have a FWD Escape 2005. Two years after the operation mine still fine, well, I mean the drive part.

 

I used my floor jack and raised the front of the Tribble up by the radiator cross member and chocked the rear wheels. I started the truck and put it drive. I slowly released the brake and the front wheels started turning and there was no effort for the truck to creep forward. My son reported the driveshaft was not moving while the front wheels were turning. According to the technical description, this Haldex system can provide up to 100% torque to the rear wheels if the front wheels are slipping. Something mechanical broke - might be the PTU, the intermediate shaft, or something at the diff in the transaxle. Any of those require major mechanical disassembly and most likely expensive parts cost. The engines in these do run forever but I know I'm already on bonus time with the CD4E automatic at 180K miles, and it's a sure thing if I sink money into the AWD, the trans will quit soon after.

Other than the loss of AWD, there are no other symptoms and the truck otherwise runs fine, so I'm inclined to leave the rear drive components in place. We're approaching the end of winter so I'll use it into the fall when hopefully the price of cars will drop. I do need the AWD as I'm in a hilly part of CT.

John