[Assi]

By the way, what battery tester do you have? Might actually be the same as I have...

It is just a cheap Amazon one:

 

[Assi]

My thought now is to check for power drain, with multimeter and taking fuses out. Not sure it is simple, or will help.

 

[Gary Kline]

It is just a cheap Amazon one:
View attachment 238205

Same, mine was like USD $15 or so. I just checked my battery and the charge is low so I put it on my charger/maintainer. Again, it's been cold and I haven't driven it more than a block or so in about a week. I purchased the car in September 2021 and the battery was already in it so I don't know how long before the previous owner purchased it but it's been 3 years & 3 months with me already. I'm glad the 2014's don't have ESS - I'm sure it would have been depleted by this point if it had to constantly start the car from an ESS system.

 

[Assi]

Does anyone happen to know what initiates the "Battery Voltage" message? Is there a sensor?

 

[Assi]

Still "Battery Voltage".
I did some "meaningless" things, like turning off the back cabin lights that were left on, or inspecting some wires (just a few), or charging the new battery fully.
I always get the "Battery Voltage" message.
When reading the faults, there are occasional different faults - mainly of communication.
Somtimes the steering wheel is free - drove 100 meter and the steering got heavy again.
I guess it is all due to the charging problem.

Then I did the power drain test with a multimeter. There are many posts and youtubes about it (this is how I understood what to do) but since the behavior is different between car models, I am putting here the values I got - if someone will need a reference for his Jeep in the future.
In short, you disconnect the negative Bettery cable, touch a multimeter between the cable and the negative battery terminal and messure the current.
If it is less than 50ma then you are good (there is always something working). But if you get more then you can start disconnecting fuses from the fuse boxes one by one until you see the current dropping.
Now, you must make sure that everything is off, for example the door is closed, and that the keys are far.
Another thing to notice is that even after shutting the ignition you will still have some lights or computers running for some time depending on the car model.
So, in my Cherokee, TH 3.2L 2015. I disconnected the negative cable, and when I put the multimeter between the cable and the battery terminal I heard a bleep (it is closing thd circuit), and the light on the instrument cluster went on. I read 350-400ma.
After a minute or so, the instrument cluster lights are off and the reading drops to around 200ma.
After maybe half a minute, it drops to around 80ma, and then to 38ma. And that's looks OK.

Next I think to check voltage in different points, from the battery to the steering maybe or will see.

 

[Assi]

Yes, definitely interested how to get it down for service that would be great thank you

Added in here how to remove the PTU:

https://www.jeepcherokeeclub.com/threads/removing-the-ptu-drive-axle-driveshaft-catalytic-converter.252145/

 

[Flechtight]

Added in here how to remove the PTU:

https://www.jeepcherokeeclub.com/threads/removing-the-ptu-drive-axle-driveshaft-catalytic-converter.252145/

Did you by any chance look into the breather tube location on the PTU while you had it apart, did you notice if anything would prevent the use of the breather tube as a fill port on Ad2.

filling from bottom up ( for those drilled drained plug users) is nice, but when you remove the line to install the plug, the oil is like water running out.

 

[Assi]

Did you by any chance look into the breather tube location on the PTU while you had it apart, did you notice if anything would prevent the use of the breather tube as a fill port on Ad2.

filling from bottom up ( for those drilled drained plug users) is nice, but when you remove the line to install the plug, the oil is like water running out.

The breather tube:

It is just a hollow metal tube. For example, when I tilted the PTU at some point, oil got spilling from it...so.

The breather is a rubber hose that is pushed onto it.

It goes up from the PTU next to the firewall, and connected somewhere with this clips (I think you can reach it from above).
Note that at its end there is a some kind of breather plug - or something.

 

[Flybynightcru]

So, why not just use the fill ports??? You know how much came out, so you kinda know how much goes back in...🤔😉😎

 

[Gary Kline]

Did you by any chance look into the breather tube location on the PTU while you had it apart, did you notice if anything would prevent the use of the breather tube as a fill port on Ad2.

filling from bottom up ( for those drilled drained plug users) is nice, but when you remove the line to install the plug, the oil is like water running out.

Hey @Flechtight , you mean instead of drilling out (adding through the vent and draining from the fill plug) or do you mean just as a filling port? There's a plug/filter at the end that would need to be pulled out.

 

[Flechtight]

Hey @Flechtight , you mean instead of drilling out (adding through the vent and draining from the fill plug) or do you mean just as a filling port? There's a plug/filter at the end that would need to be pulled out.

So, why not just use the fill ports??? You know how much came out, so you kinda know how much goes back in...🤔😉😎

looking for a cleaner alternative. The fill port is blocked, and only small amounts can go in at a time without it running back out.

if I can drain my PTU, clean and seal the plug threads before filling, would be optimum.

I felt like the boy with his finger in the dike, as soon as I pulled the fill line out of the drain plug oil just ran Out… fast

 

[Flechtight]

The breather tube:
View attachment 238715


View attachment 238716

It is just a hollow metal tube. For example, when I tilted the PTU at some point, oil got spilling from it...so.

The breather is a rubber hose that is pushed onto it.
View attachment 238717

It goes up from the PTU next to the firewall, and connected somewhere with this clips (I think you can reach it from above).
Note that at its end there is a some kind of breather plug - or something.

View attachment 238718

Thanks, I think that may work if I can get the tube off from above and then install a feed line and fill top down and wait for the oil to spill out fill port.
I have some time before I drain and fill again but I now have something to investigate.

 

[Flybynightcru]

looking for a cleaner alternative. The fill port is blocked, and only small amounts can go in at a time without it running back out.

if I can drain my PTU, clean and seal the plug threads before filling, would be optimum.

I felt like the boy with his finger in the dike, as soon as I pulled the fill line out of the drain plug oil just ran Out… fast

What about something like the Fumoto type quick drain plug with a valve shutoff??? Something you can put a hose on from your pump...🤔😉😁

 

[Flechtight]

What about something like the Fumoto type quick drain plug with a valve shutoff??? Something you can put a hose on from your pump...🤔😉😁

View attachment 238725

View attachment 238726

🤔

 

[rumrunner]

why would a breather tube be plugged at the end?

 

[Flechtight]

why would a breather tube be plugged at the end?

To keep things out while allowing air to come and go 😁

 

[AZJeeper]

why would a breather tube be plugged at the end?

The "cap" is a loose-fitting top that sorta protects the breather tube from ingesting too much gunk. They are considered a "one-way valve" but really that's not true. They equalize air pressure as the oil expands AND contracts. For example, when you go through a water crossing, the hot oil cools off and the breather lets the air back in, sometimes rather quickly! If it were truly a one-way valve the contracting oil would create a vacuum. The oil seals likely would give. There are some spring-loaded breather ends that can be mounted in any direction. The loose kind (like the one in the picture above) must be installed with the end of the breather hose pointing up so the cap can flop down on the end of the valve body to provide that bit of gunk protection.

The breathers are usually one of the 1st things that will ingest water and are set a tad above the max fording depth. The breathers do nothing to keep water out if they get submerged (as @Bob Blaylock might attest ). I have the same breather ends on my JKU. I've routed the breather to be WAY above the waterline. Haven't done anything to the breathers on the Cherokee.

Some Wrangler owners replace the breather end with a small fuel filter. ARB also makes a very expensive filter system. Those "solutions" are overkill IMO.

 

[Assi]

Disaster. The PTU went BOOOOOOOM!!!!!
I just wanted to update (actually, I didn’t really want to update, but still...).

At first, I found out by chance (checking the oil) that I had a broken pin in the PTU and the oil was a silver sludge. There were no faults or “4WD SRV” light on or something.
I took out the PTU and fixed the pin (as appear in the posts above). I still think this fix, as suggested by @Roof_top_tent_indianer, is good (I think).

I put the PTU back and it didn’t work well – stuck in 4LOW, and faults etc.
I opened the PTU again, and saw that the forks position was not right (as appear in the posts above) and assumed that this was the problem.

I put the PTU back. Driving on 2HI was ok, but once in an hour or so I got the C14A7 “PTU Motor, Component or system operation blocked” fault. I also got once the C1496. And I couldn’t get into 4LOW.
I thought that it might be the motor, as seen others writing, this is usually the problem. I did check the motor the first time I took the PTU out, opened it and it looked good, but I thought that maybe it got damaged by this.
So I ordered a new motor, replaced it (and also soldered a little wire since the pin connecting the motor to the board was broken).

BTW – not really relevant here, but I also got many steering related faults and the steering wheel was hardly turning. Cleaning the F30 fuse and cleaning the G904A and G907 ground connections fixed it all (this issue appears in some threads in this forum).

I put the PTU back. All looked good at the beginning. No faults at all, and driving for 30 minutes on 2HI (didn’t try 4LOW yet).
Then, after another 20 minutes of calm driving, I got the C1496 fault. I tried to clear it by playing with the 4WD LOW knob, and putting it at “Sport” mode, and using AlfaOBD to “relearn” etc.. (it worked for me before, as I wrote in another thread), it didn’t work at first, but then it got cleared – not sure why, maybe the PTU cooled down, or just playing enough.

So I derived for another 30 minutes, all looked good, and then I got BOOM.
Strong metal noise. Immediately there was no going forward or reverse (putting the transmission on drive or reverse acted like it was on neutral).
And there was still noises - for a while (maybe until I put it on neutral).
No movement at all, got some people helping to push the Jeep away from blocking the road.
I put in Parking, and there was grinding noises, so I turned the engine off, but turning it again on, and there were no grinding noises.
I put the transmission on neutral. There were no noises on neutral. The engine was running, the steering wheel working, and the breaks.
I towed the Jeep to the parking place, with another car, connected with a strap in front of me. There were no noises, most of the time, but once or twice I heard for a second a metal noise.

The faults that I have are:

• General fault P215C “Output shaft speed – wheel speed correlation”.
• Under the Transmission P1720 “Output speed sensor/wheel speed rationality”.
• Under DTCM the C14A7 and also C1477 “Transfer case clutch, over temperature”.
• Under Parking I get U0403 “implausible data received from the T-case”

What I think is that the PTU is broken – really don’t know why.
But I am not sure about the Transmission, and this is of course adding a big concern. A broken PTU can cause damage to the transmission (and I don’t have Drive or Reverse). But it can be some “limp mode”.
I found this short YouTube, for this exact transmission and PTU, with almost the same errors (but no metal boom), and it got fixed when replacing the PTU

That’s the situation.

I have few questions, if someone can give an advice:
1. If I put a new PTU, but the transmission is broken, can it damage the PTU? I am not talking about diving like that but on trying to just replace the PTU.

2. How do I check the transmission? I thought first to check the oil – but it might not show anything. I thought also of raising the front wheels, turning them to check if I hear noises, but I might not hear anything since riding in neutral didn’t make any noise.
I also thought of taking out the PTU, Driveshaft and the right Axle shaft. Leaving the actuator and all the sensors connected. Raising the front wheels, running the engine, and trying to change gears manually. But I am not sure, if it will work without the PTU, if I can hear noises without the PTU resistance, etc..
So, any ideas of how to check the transmission?

3. New PTU at moparpartsgiant costs 2400$ + 500$ +1200$ shipment.
On eBay there are remanufactured ones, in about ~1000$ including shipment.
For example:
1PC Power Transfer Unit Case 2 Speed 68307403AG For 2014-2018 Jeep Cherokee | eBay

You can search eBay for 68307403ag (correct me if I am wrong and this is not the right number…)

I don’t like buying form eBay, and would prefer new of course, but it is about one quarter of the new one price.
I also saw YouTube that someone bought one, and it looked good, with new motor and gaskets and so (but he didn’t update after installing it).
Does anyone have an experience with it? Do you see any difference between the PTUs listed on eBay, any recommendations?

 

[Flechtight]

First off, sorry to hear about your PTU after all the work you put in, I was hoping you got it figured out and back on the road.

Have you hooked up Alpha and seen where the PTU fork is currently sitting? 2hi/4hi or somewhere in between?

I suspect you will learn more when you pull it out…..again

keep us posted

 

[Gary Kline]

Disaster. The PTU went BOOOOOOOM!!!!!
I just wanted to update (actually, I didn’t really want to update, but still...).

At first, I found out by chance (checking the oil) that I had a broken pin in the PTU and the oil was a silver sludge. There were no faults or “4WD SRV” light on or something.
I took out the PTU and fixed the pin (as appear in the posts above). I still think this fix, as suggested by @Roof_top_tent_indianer, is good (I think).

I put the PTU back and it didn’t work well – stuck in 4LOW, and faults etc.
I opened the PTU again, and saw that the forks position was not right (as appear in the posts above) and assumed that this was the problem.

I put the PTU back. Driving on 2HI was ok, but once in an hour or so I got the C14A7 “PTU Motor, Component or system operation blocked” fault. I also got once the C1496. And I couldn’t get into 4LOW.
I thought that it might be the motor, as seen others writing, this is usually the problem. I did check the motor the first time I took the PTU out, opened it and it looked good, but I thought that maybe it got damaged by this.
So I ordered a new motor, replaced it (and also soldered a little wire since the pin connecting the motor to the board was broken).

BTW – not really relevant here, but I also got many steering related faults and the steering wheel was hardly turning. Cleaning the F30 fuse and cleaning the G904A and G907 ground connections fixed it all (this issue appears in some threads in this forum).

I put the PTU back. All looked good at the beginning. No faults at all, and driving for 30 minutes on 2HI (didn’t try 4LOW yet).
Then, after another 20 minutes of calm driving, I got the C1496 fault. I tried to clear it by playing with the 4WD LOW knob, and putting it at “Sport” mode, and using AlfaOBD to “relearn” etc.. (it worked for me before, as I wrote in another thread), it didn’t work at first, but then it got cleared – not sure why, maybe the PTU cooled down, or just playing enough.

So I derived for another 30 minutes, all looked good, and then I got BOOM.
Strong metal noise. Immediately there was no going forward or reverse (putting the transmission on drive or reverse acted like it was on neutral).
And there was still noises - for a while (maybe until I put it on neutral).
No movement at all, got some people helping to push the Jeep away from blocking the road.
I put in Parking, and there was grinding noises, so I turned the engine off, but turning it again on, and there were no grinding noises.
I put the transmission on neutral. There were no noises on neutral. The engine was running, the steering wheel working, and the breaks.
I towed the Jeep to the parking place, with another car, connected with a strap in front of me. There were no noises, most of the time, but once or twice I heard for a second a metal noise.

The faults that I have are:

• General fault P215C “Output shaft speed – wheel speed correlation”.
• Under the Transmission P1720 “Output speed sensor/wheel speed rationality”.
• Under DTCM the C14A7 and also C1477 “Transfer case clutch, over temperature”.
• Under Parking I get U0403 “implausible data received from the T-case”

What I think is that the PTU is broken – really don’t know why.
But I am not sure about the Transmission, and this is of course adding a big concern. A broken PTU can cause damage to the transmission (and I don’t have Drive or Reverse). But it can be some “limp mode”.
I found this short YouTube, for this exact transmission and PTU, with almost the same errors (but no metal boom), and it got fixed when replacing the PTU

That’s the situation.

I have few questions, if someone can give an advice:
1. If I put a new PTU, but the transmission is broken, can it damage the PTU? I am not talking about diving like that but on trying to just replace the PTU.

2. How do I check the transmission? I thought first to check the oil – but it might not show anything. I thought also of raising the front wheels, turning them to check if I hear noises, but I might not hear anything since riding in neutral didn’t make any noise.
I also thought of taking out the PTU, Driveshaft and the right Axle shaft. Leaving the actuator and all the sensors connected. Raising the front wheels, running the engine, and trying to change gears manually. But I am not sure, if it will work without the PTU, if I can hear noises without the PTU resistance, etc..
So, any ideas of how to check the transmission?

3. New PTU at moparpartsgiant costs 2400$ + 500$ +1200$ shipment.
On eBay there are remanufactured ones, in about ~1000$ including shipment.
For example:
1PC Power Transfer Unit Case 2 Speed 68307403AG For 2014-2018 Jeep Cherokee | eBay

You can search eBay for 68307403ag (correct me if I am wrong and this is not the right number…)

I don’t like buying form eBay, and would prefer new of course, but it is about one quarter of the new one price.
I also saw YouTube that someone bought one, and it looked good, with new motor and gaskets and so (but he didn’t update after installing it).
Does anyone have an experience with it? Do you see any difference between the PTUs listed on eBay, any recommendations?

Hey @Assi,

Also, really sorry to hear this happened as well . The video you posted just describes the well-known issue that oil flung around in the PTU can find its way into the motor and PC Board of the PTU actuator causing it to fail. This is well known and as you mentioned, you even changed the motor as a precaution. Note, what the person in the video says about the actuator seal isn't accurate either. The seal is available separately as a part. In addition, even if it weren't, anyone could just use RTV if they wanted to make a seal as well. Perhaps the video is very old?

Regarding your questions.... Clearly the "Boom" isn't good.

1. First thing I'd do is pull the skids plates and visually inspect underneath. If the boom was large and the PTU, it could mean a case crack on the PTU which you could visually see (as well as see the oil coming out). It could have been the bolts sheared etc. Either way, step #1 is a visual inspection.

2. Could the PTU cause the transmission to break? Tough to say. The transmission is actually pretty robust (strong), it's actually rated up to almost twice the torque of the V6 engine however a gear catching at the wrong angle etc. and who knows. As you didn't previously have transmission problems AND the PTU was recently worked on, I'd say the issue is more likely with the PTU just by that but whether that caused damage to the transmission, it's hard to say. Yes, you could drain the trans. oil and look for debris but as you mentioned, it may or may not show anything. You could use an endoscope in the fill port and see if you see any metal chunks that way but the field of view won't be large.

3. What you mention about checking w/o the PTU I don't think will work. The AD2 PTU has the differential for the left and right front wheels in it so without it, the wheels won't turn. (FWD and AD1 Cherokees have the differential in the transmission casing but not the AD2 which you saw the diff when changing the roll pin). If you were going to do this test JUST to see if the transmission makes any grinding noises, then it might work (car won't move but the transmission parts I think would still move. You get a bunch of codes/errors from the wheel sensors etc. but it might work if you're just listening to see if you hear grinding in the transmission.

4. The errors you posted relate to the PTU (the P1720 is probably because the transmission sees its output shaft spinning like the car should be moving but the wheel sensors say the car isn't) so I don't see this code as any indication of transmission damage. Just that the car isn't moving as expected.

5. Perhaps pull the PTU first (you're a pro and probably know it better than most Jeep mechanics), take off the actuator and see if you see damage inside the PTU that could account for the boom. I hate to say it this way but, the more PTU damage you see, probably the better it is in terms of that was what you heard. If you take the PTU apart and it all looks like it was before, then the more the transmission looks suspect. Know what I mean? BTW, any chance the grinding is the PTU fork trying to synchronize the gears and it's not in the correct position or is the grinding much louder/larger?

Hope this helps