This morning I had my new revision from Torrie so I thought I would test it out. First wot was from a dig and the front tires spun like crazy so I let out. Second time was from around 20-25mph with the same results? Could this be my PTU going out or tune related? This morning was the first time I've ever noticed the car not engaging the rear wheels so I'm pretty worried
Were you normal-launching or brake boosting? What tires do you have on now, tread depth, and at what psi? May need to disconnect the neg terminal on the battery for 30 seconds, let it relearn.
Usually datalogging and dialing in the torque management helps a lot, so I would do that with Torrie.
I doubt that it is tune related. Traction control can hide a bad PTU. I'm guessing you turned off the TC to test the tune and that exposed the bad PTU.
Quote from: SHOdded on June 30, 2016, 09:48:25 AM
Were you normal-launching or brake boosting? What tires do you have on now, tread depth, and at what psi? May need to disconnect the neg terminal on the battery for 30 seconds, let it relearn.
Usually datalogging and dialing in the torque management helps a lot, so I would do that with Torrie.
This was a brake boost launched from a dig but acted the same going wot from a roll? This is with stock Michelin's which never spun like that before.
Quote from: sholxgt on June 30, 2016, 10:02:58 AM
I doubt that it is tune related. Traction control can hide a bad PTU. I'm guessing you turned off the TC to test the tune and that exposed the bad PTU.
Yes, traction control was off which I always do before launching the car. This just happened to be the first time all power went to the front wheels and spun like crazy
The ptu is spinning all the time and it keeps the driveshaft spinning...the rear end is electronically activated when needed so i doubt its the ptu
Quote from: AJP turbo on June 30, 2016, 11:19:37 AM
The ptu is spinning all the time and it keeps the driveshaft spinning...the rear end is electronically activated when needed so i doubt its the ptu
Hmm...I see what you are saying AJP. Strange thing is there have been several reports of dealers replacing the PTU on cars with non-functioning AWD. If it is seized, is there something between it and the motor that can slip instead?
My understanding is that, on the cars with a failed PTU, the driveshaft has not been spinning to provide power to the rear.
Your right front half shaft is what actually engages the PTU as AJP said. I highly doubt
there's a mechanical issue causing it not to spin, you would definitely know.
Have you talked to Torrie? Any awd off lights on the dash? If your running torque there's a PID for the awd engagement from the clutch pack.
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If I drive aggressively and heat up the drivetrain I get excessive wheel spin from the front wheels.
When I pull over, turn off the car and let it cool for 5-10 minutes it goes away.
I am leaning towards the RDU getting overheated.
Quote from: Gray Brick on June 30, 2016, 12:42:27 PM
If I drive aggressively and heat up the drivetrain I get excessive wheel spin from the front wheels.
When I pull over, turn off the car and let it cool for 5-10 minutes it goes away.
I am leaning towards the RDU getting overheated.
Had the same thing happen to me last night at NED. If I hot lapped, by the time I got to the 3rd or 4th run I was pretty much running FWD only it seemed from all the extra hop I would get.
Need to get some AMSoil into these parts.
Quote from: glock-coma on June 30, 2016, 12:20:22 PM
Your right front half shaft is what actually engages the PTU as AJP said. I highly doubt
there's a mechanical issue causing it not to spin, you would definitely know.
Have you talked to Torrie? Any awd off lights on the dash? If your running torque there's a PID for the awd engagement from the clutch pack.
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I've spoken to Torrie and he wants me to retrieve the stock files and send to him before anymore flashing. There wasn't any dash lights on at all but this happened 5 minutes before getting to work in the am. I hope this can be resolved without returning to stock before bringing to the dealership
Keep us posted and good luck!
Quote from: sholxgt on June 30, 2016, 04:39:26 PM
Keep us posted and good luck!
Thanks!
Well, I loaded my last tune and the awd system worked fine this morning. It's hard to say if yesterday was a fluke or if it was something in the revision. I'm going to send the current file to Torrie after work to see if he can find anything but it runs great so far!
Do we know what would cause the rear to not engage?
Is there a temp sensor in the RDU giving the awd notification it is hot?
What about in the PTU?
Or something else?
I recall reading somewhere that is has its own temp controlled cutoff. Not sure how it works though.
I found a couple of articles on the PTU/RDU for ya. Z Since the Power Transfer Unit operates all the time to spin the driveshaft to the rear, the PTU can get hot. On the police version, a number of steps are taken to assure reliability and durability in police use. First, a cooler is added to the front of the PTU housing. The police-only PTU housing has an integral water jacket connected with water lines that run to the bottom three coils of the radiator. The jacket receives engine coolant from the radiator to maintain the correct PTU oil temperature.
Second, the PTU has a gear lube temperature sensor. A module keeps track of the gear lube temp, and how long / how often it was at that temperature. When a threshold is reached, a change PTU Oil light activated.
Finally, the AWD system has a two-stage way to protect itself from damage during extreme, prolonged use. The ATC as a heat protection strategy based on a number of factors, including wheel speed and duration of activity, to determine if overheating is occurring. If the ATC detects overheating, it will lock the clutches together to cool them. Clutches that slip to provide partial torque transfer get hot from the friction of the slippage. Locking the clutches stops the slip and cools the entire unit. In a locked condition, power is transferred to the rear wheels.
If the temp continues to rise even in a locked condition, the PCM disables the coupling altogether. The vehicle operates only as a FWD. AWD OFF is displayed. On the Police Interceptors, the PCM will automatically exit heat protection mode and clear the AWD OFF message when the temp returns to normal. This whole process is sped up by turning the ignition off and allowing the vehicle to cool for 10 minutes.
The ATC/RDU used on the Police Interceptors uses fluid-filled "wet" clutch packs. The retail Taurus and Explorer use dry clutches. The PI wet clutches can withstand higher temps and withstand higher temps longer than the retail unit. The ATC and RDU are not field serviceable. In case of a problem with either system, the whole unit is replaced.Police-only Cooling
The police version of AWD has three unique features to improve durability during severe use. First, the Power Transfer Unit on the AWD system uses a police-only auxiliary cooler. The retail AWD unit is air cooled, i.e., the aluminum housing dissipates heat to the surrounding air. When the vehicle is stationary, the amount of cooling is obviously less than when the vehicle is moving.
On the police AWD unit, the front housing of the Power Transfer Unit has a special water jacket cast into the assembly. The integral PTU auxiliary cooler is part of the water cooling system. That means the cooling remains "active" since the cooling water is constantly circulated, whether the police vehicle is moving or stationary. The PTU cooler is plumbed into the bottom of the radiator, where the water is cooler than at the top of the radiator.
Second, the Power Transfer Unit uses an internal temperature sensor, not found on the retail unit. A module keeps track of oil temperature in the PTU and the amount of time spent at that temperature. An electric clutch pack engages and disengages as torque is transferred to the rear wheels.
Both the PI Sedan and PI Utility default to FWD under normal conditions. As the front wheels slip, torque is selectively diverted to the rear wheels. A time versus temp logarithm activates an Oil Minder light in the driver message center if and when it is time to change the PTU fluid. The special synthetic oil may last 100K miles in normal police use.
Third, the Rear Differential Unit on the police version uses a fluid-filled clutch pack, while the retail version uses dry clutches. The fluid-filled RDU can withstand more severe duty.
The cooling ability of the police-only auxiliary radiator-water jacket combination was tested in 110 deg. F weather. Hard driving—where power is constantly shifting from front to rear, back and forth—can take many different forms.
Think aggressive driving during a city pursuit: hard throttle for a city block, 90-degree turn, hard throttle, where torque definitely shifts from front to rear. Also think getting unstuck in desert sand. Even though the vehicle and wheel speeds are not high, torque is constantly shifting between the front and rear spinning wheels.
Under the worst conditions of high-torque, clutch engagement and disengagement, the synthetic oil reached temperatures around 195 deg F. The special lube is rated for temps just over 500 deg F. The air-to-water cooler works... Some AWD drivetrains are so sensitive that you must have exactly the same tread depth/tire wear on all four times. If your times are half worn and you must replace one tire with a new one, you must actually replace all four tires so the trend depth (overall tire height-diameter) stays the same.
Not so with the Ford AWD system. The AWD controllers are tolerant of any tread depth differences. The PI Sedan and PI Utility can accommodate two new tires on the front and two half-worn tries on the rear, or one new one or three new one.....Hope this helps any. Z
Glad it started working on the previous revision. You can try and load the newest revision again and test. The only time I had this happen was when I did a massive brake boost launch, it held perfectly but when I proceeded to do my next run a few minutes later it did not engage the rear at all. I just let the car cool down for 10-15 minutes and it was fine. No codes or anything.
Quote from: Scott4957 on July 02, 2016, 12:31:32 AM
Glad it started working on the previous revision. You can try and load the newest revision again and test. The only time I had this happen was when I did a massive brake boost launch, it held perfectly but when I proceeded to do my next run a few minutes later it did not engage the rear at all. I just let the car cool down for 10-15 minutes and it was fine. No codes or anything.
I've considered loading the latest tune again to test but may wait to hear back from Torrie before doing so. Whenever this happened it was from a brake boosted launch with only 5 miles or so on the tune. From the information above it may have been some sort of safety to keep the awd safe from overheating. Whatever caused the excessive front tire spin sure makes one nervous and immediately think of the worst