PTU Leaking, Check AWD message.

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Eric Morris

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So I got under my 2015 to change the oil (I love the twist-lock fasteners on the belly tray) and noticed a bunch of oil coming from the PTU. It must have started recently as it's dripping enough to leave spots where I park and it wasn't like that a few months back. I'm still under power train warranty, so it won't cost me anything. You guys think they'll try to replace seals or just replace the whole PTU with a new unit?

I've also been getting the "Check AWD" message and the wrench every few days. AFAIK, the PTU should have nothing to do with that, correct? Meaning, are there any electrical senors hooked to the PTU that could be causing that?

I have a feeling it's something in the RDU/rear axle causing it as it typically pops the light on after taking a sharp corner. I've heard they don't service the RDUs, but just swap them out, is that correct?

One more question for you guys- does the car set an error code when the "Check AWD" message comes up, or do I have to actually drive it to the dealer with that light on to prove it's happening? The light and wrench goes away when re-started. I have been taking pics with my cell phone every time to document it.

It's going in at the end of the month to be worked on.
 

Majestic

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So I got under my 2015 to change the oil (I love the twist-lock fasteners on the belly tray) and noticed a bunch of oil coming from the PTU. It must have started recently as it's dripping enough to leave spots where I park and it wasn't like that a few months back. I'm still under power train warranty, so it won't cost me anything. You guys think they'll try to replace seals or just replace the whole PTU with a new unit?

I've also been getting the "Check AWD" message and the wrench every few days. AFAIK, the PTU should have nothing to do with that, correct? Meaning, are there any electrical senors hooked to the PTU that could be causing that?

I have a feeling it's something in the RDU/rear axle causing it as it typically pops the light on after taking a sharp corner. I've heard they don't service the RDUs, but just swap them out, is that correct?

One more question for you guys- does the car set an error code when the "Check AWD" message comes up, or do I have to actually drive it to the dealer with that light on to prove it's happening? The light and wrench goes away when re-started. I have been taking pics with my cell phone every time to document it.

It's going in at the end of the month to be worked on.


My guess on the error message is the steering wheel control module. I had the same issue at one time. Here's the thread:

https://shoforum.com/index.php?threads/dtc-questions.134759/
 

SaveMelMac

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I would bring it in as soon as you can before she blows. I had my ptu replaced under CPO warranty it was leaking. They replaced the complete unit without question. With such little fluid in the ptu just replacing the seals I would worry about the long term damage.
 

SHOdded

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Check AWD usually refers to a bad 4x4/AWD module, a bad ATC in the RDU, or a bad electrical connector at the ATC.
 

Lostneye

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I had my PTU replaced due to a leak but I did not notice it spotting on the ground so the damage was done. If the bearings look good they may try and just fix the leak.
 

Eric Morris

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So I got it back last night- they replaced the seal going out the back for the driveshaft.

After 30+ miles, it still reeks of gear oil and it left a dark spot on the driveway last night. I know a seal might need to wear in some, but I think 30+ miles is enough for that. Going under it tonight to see if they even cleaned anything up at all, or what's going on. I have a feeling it'll be back at the dealer soon.

The "Check AWD" message was from a loose pin in one of the electrical connectors. Impressed they found that, not so impressed with the new seal so far.
 

Jeff2017

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A new seal shouldn't leak at all. Sounds like you are getting a new PTU.
 

sperold

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New seals, if they are the correct ones, only leak if the c0ntact surfaces are not lubricated when they are installed.
By the time the lubricant gets to it "accidentally", the lip of the seal is ruined.
 

Eric Morris

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So I put it up on ramps in the garage- the PTU looks dry directly under the new seal, so I think it's good.

They didn't clean any of the oil up at all- slackers. I wiped it down, and the smell seems a lot better, but I think I'm still getting a whiff from the cross member getting heated by the exhaust piping, and the cross member still has oil down inside of it. I just need a week of heavy rain to wash it all out.

As for the seals and new ones leaking, I agree with the logic- but the reason I said that is when I had a R&P done in a 8.8 by our mechanic at the time, the new pinion seal was weeping a little bit after driving it straight home. He said take it out and drive it more and it'll stop. He was right, it stopped and never leaked again.
 

Eric Morris

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It still reeked of gear oil after wiping it all down (1/3 as bad though), so it went up on ramps in the driveway last night and I broke out the engine degreaser, then hosed it off. No gear oil smell this morning for the first time in a month.

The check AWD light has not come back on, and it would have by now, so the loose pin they found was the culprit for sure.
 

SM105K

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Do you have the splash guard still. Make sure you clean that as well.
 

Eric Morris

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Yes, but luckily it had no oil on it since it was a leak from the rear output seal.
 

Christian

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Yea, it's under drive train warranty (42K). And I bought the extended warranty to 100,000.

Why don't you just bring it in? If it's under warranty, the problem is theirs. Take it in, get a courtesy car, and drive away two days later with a repaired vehicle. That's what you paid for.
 

Eric Morris

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Why don't you just bring it in? If it's under warranty, the problem is theirs. Take it in, get a courtesy car, and drive away two days later with a repaired vehicle. That's what you paid for.

Uhh- I did, and it's been fixed.
 

Eric Morris

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Don't worry about it...

So another drive today to work. No gear oil smell, and the last of the de-greaser smell is gone too. Happy days.
 

SM105K

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Don't worry about it...

So another drive today to work. No gear oil smell, and the last of the de-greaser smell is gone too. Happy days.

Good, gear oil smell is the worst.
 
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