“AWD off” message on long drive

jus2quik said:
Sorry buddy, I did immed. Check for codes and nothing was there. I wish my wife would have told me sooner but her being 5 hours away from home I could not have done much and trying to talk someone through adding ptu fluid wasn’t gonna happen,my family aren’t mecahnics,just farmers up that way.Thanks again !
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No worries! Glad you were able to find the FIll Hole! Best of luck.  Z
 
Oh yeah I’m good at it now ! Just got messed up with many folks saying just add what you take out ,then I read here somewhere to gently top it off but if there is not a heat sensor on the ptu then the “awd off” heat signal must have come from the RDU,right? I checked that fluid as well and it was good,I didn’t change it but I did check it . All we have seen is that message a few times on one trip,never lost awd or had front only pulling that I can tell .
 
Yeah, it is triggered by some situation with control of the RDU, not usually by the PTU itself.  Since many people have PTUs that had been gunked down to basically solid gunk, and the AWD still worked fine, I am not sure that having only 10 oz in there was the cause of the AWD OFF message.  I think all should be well now tho.  As I said before, the ony other item you can check is the electrical integrity of the connection at the ATC.
 
Since you may have burned up some of the life in the fluid, I would do a full dump and put in Amsoil etc...I'd also d the pigtail so you can change ptu quick.
 
SHOdded said:
Social media is a real crapshoot.  Since messaging occurs rapidfire, a lot of folks leave their filters off.  Can get ugly real fast.

It happens on this forum on occassion, but thankfully our members keep it to a minimum :)
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I don't know what you are talking about......
 
Checked rear rdu fluid and it’s clean and full,air pressure in all tires the same ,only thing 8 have found that is suspect is the rear tires are of a different brand than the front . Same size but thinking about how if the rear or front tires are of different “ real “ size after a few hours I could imagine the clutches could “ possibly” heat up and cause the code,you guys think this is a possibility ? I believe the Rdu is the only component with a sensor correct ? Thanks fellas for the help !
 
If you have a PP, then the PTU has a temp sensor.  Otherwise there are no sensors in the AWD system itself.

Have not heard of tread design causing problems unless the AWD is in action continuously for a long period of time. Traction differences are handled by AdvanceTrac dividing the speed and power as appropriate.

It is possible that a hub problem has developed, but even then I have not seen such a message go off.  Does the ptu fluid look good?  Then we are back to tire pressures or 4x4 module or damaged wiring/dirty connectors.
 
So no heat sensors or electronic sensors  in the rdu unit itself,right? Clutch engagement is manual not electronically actuated? I don’t have a PP car.
 
Clutch actuation is electronically actuated.  The 4x4 module tells the RDU when and how much clutch to apply.

But no sensors otherwise in the RDU, no.  There is supposed to be a heat protection mode for the RDU, but I am fuzzy on how it actually works.  Probably related to the solenoid in the ATC that controls the clutch.

Heat Protection Mode
During very extreme off-road operation, the AWD system utilizes a heat protection mode to protect the active torque control coupling (ATCC) solenoid (part of rear axle) from damage. If the system detects an overheat condition, it enters a locked mode. If the heat in the system continues to rise once in the locked mode, the 4X4 control module disables the ATCC solenoid. Allow the system to cool down at least 10 minutes with the ignition switch in the ON position.
 
Has the AWD OFF in Dash returned! If not wouldn't worry to much IMO!

The Powertrain Control Module sends a signal to partially or fully engage or disengage the Rear Wheel Drive part of the AWD. Based on input from the (four wheel sensors) feeding the ABS module, the steering-angle sensor module, and the instrument cluster module, the PCM sends a signal to the AWD really module and the 4x4 lock solenoid in the Active Torque Coupling.  Z
 
Signal came one once about 4 hours into a trip and about 3 hours on the way home my wife said,she is about to take the car on a 1 month trek across the country with a friend next month and don’t want her to have any issues .we do normal 1 or two hour round trip drives and never had an issue. I’m gonna put some new tires on it before her trip ,I’m sure it will be fine.From what I’m reading the tires don’t have to be so precisely the same size to matter .
 
ZSHO said:
Has the AWD OFF in Dash returned! If not wouldn't worry to much IMO!

The Powertrain Control Module sends a signal to partially or fully engage or disengage the Rear Wheel Drive part of the AWD. Based on input from the (four wheel sensors) feeding the ABS module, the steering-angle sensor module, and the instrument cluster module, the PCM sends a signal to the AWD really module and the 4x4 lock solenoid in the Active Torque Coupling.  Z
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What do you mean by partially engage? Does the clutch in the unit actually partially slip under certain conditions? I thought it was either on or off.
 
jims2015 said:
ZSHO said:
Has the AWD OFF in Dash returned! If not wouldn't worry to much IMO!

The Powertrain Control Module sends a signal to partially or fully engage or disengage the Rear Wheel Drive part of the AWD. Based on input from the (four wheel sensors) feeding the ABS module, the steering-angle sensor module, and the instrument cluster module, the PCM sends a signal to the AWD really module and the 4x4 lock solenoid in the Active Torque Coupling.  Z
Click to expand...

What do you mean by partially engage? Does the clutch in the unit actually partially slip under certain conditions? I thought it was either on or off.
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The ATC in turn is controlled by the PCM. The amount of torque is infinitely variable, not just engaged-ON and disengaged-OFF.
It can deliver zero percent to the rear, like it does in the Default FWD condition. Or it can deliver anywhere from 1 percent to 100 percent of the engine torque to the rear wheels IIRC!  Z
 
If you are worried about it and don't need AWD, pull the fuse for the trip.  Will not hurt anything, but definitely avoid hard acceleration from a stop to avoid torque steer.
 
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