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Discussion Starter · #1 ·
Anyone know if there were changes made to the 2.0T for hybrid use? I'm curious to know if anything was modified to deal with the engine being cold and coming on for short bursts of power.
 

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It doesn't have a 12v starter and I can't find provisions for one so that leads me to believe the block is a different casting.

I am curious about the emissions controls as well. In our previous PHEV, once the engine comes on then it stays on until a certain temp is reached. I am not sure if the 4xe is the same. The EPA was working on specific emissions testing for PHEVs but I don't know if those have been adopted yet.
 

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Discussion Starter · #3 ·
I notice the first time it comes on, it will run a little longer. But it's perhaps 5 to 10 seconds. I did some hard accelerations yesterday. After being mostly fully electric the past couple weeks it was a kick in the pants. The speedometer looked like a blur, lol. It was shocking even coming from a sports car background.

That got me thinking about oil since the engine starts up at such high load. Off Road Pages shows the oil pressure as "--" until the engine comes on.

Did your previous PHEV have a starter?
 

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No but I plan to switch to full synthetic oil once free changes are exhausted. In colder months I will shift into sport mode to run the engine and heat it up to operating temps before letting the hybrid computer take over. The constant cold temp starting wears out starter batteries faster and likely ICE mechanical components, but the engines will probably see many fewer operating hours over the life of the Jeep so premature wear may not really be a problem.
 

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We get started by the 400v battery. So that's likely okay.
Not sure what you mean. The 12v battery under the hood controls all vehicle electronics. If this loses charge, as in my case, everything in the car is dead electrically and the vehicle will not start. If the 400v hybrid battery actually turns the engine over, it will not do it until a 12v source (ie jump) is placed on the battery under the hood.
 

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I notice the first time it comes on, it will run a little longer. But it's perhaps 5 to 10 seconds. I did some hard accelerations yesterday. After being mostly fully electric the past couple weeks it was a kick in the pants. The speedometer looked like a blur, lol. It was shocking even coming from a sports car background.

That got me thinking about oil since the engine starts up at such high load. Off Road Pages shows the oil pressure as "--" until the engine comes on.

Did your previous PHEV have a starter?
No it didn't.
Almost every other PHEV made for the North American market has a Power Split Device in place of a traditional type transmission. Those things are incredibly genius because they contain both motor generator units, a planetary gear set and a differential in a compact package. Continuously variable with no friction or primary wear surfaces. Those units use the smaller MGU1 to start the engine.

Not sure why the 4xe doesn't have that type.....likely because they aren't 4 wheel drive and probably don't perform well off road. The Chrysler Pacifica has the power split trans. The 4xe does it completely different. Less efficient, but more capable off road most likely.
 

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There is a 44 hp starter/generator on the engine (referred to as etorque) that will start the engine when needed. The 2nd 134 hp 400v motor is located in the transmission bellhousing and replaces the torque converter. There is a clutch between the 400v motor and the engine in front that provides the disconnect between the two while the engine isn't running. The 400v motor is used for electric, hybrid and regen braking energy capture functions. The etorque motor can be used to start the engine, provide additional energy/torque to the powertrain, and also add what little battery recharging it can using the "charge battery" option in the hybrid menu. The picture shown came up in a search for the 4xe transmission. It may or may not be the exact one, but it shows the motor and clutch layout used in the bellhousing area.
520

This setup is similar to the one in my Infiniti Q50s hybrid. By the way, my Q50s transmission went out at 70k miles and replacement cost for the transmission alone was over $9k - before labor. The hybrid version of the transmission is not serviceable and the manual specifically states it can only be replaced, unlike the normal gas version. Infiniti claims it has "lifetime" transmission fluid which is obviously bs. My point is that it would probably be wise to change the transmission fluid in the 4xe every 20 to 30k miles. I wonder if Jeep will make this transmission serviceable or not but the cost to do extra fluid changes will certainly be cheaper than any repair.
 

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Discussion Starter · #9 ·
Not sure what you mean. The 12v battery under the hood controls all vehicle electronics. If this loses charge, as in my case, everything in the car is dead electrically and the vehicle will not start. If the 400v hybrid battery actually turns the engine over, it will not do it until a 12v source (ie jump) is placed on the battery under the hood.
I was just saying the engine is spun up by one of the electric motors, as better explained above. The 12V electronics still run the brains and close the contact switches to the high voltage battery.

I wasn't sure which of your batteries had died. For that your high voltage must have been low too as it's supposed to monitor and keep that charged.

Normally I suspect the 4xe should be easy to jumpstart and have a longer than average battery life.

If the high voltage system were depleted beyond use than I think the whole system would be down until recharged. But the computer seems to protect this from happening.

One of the YouTubers purposefully depleted his gas and then the battery. I think it completely shut operation off around 30%, forcing him to then refuel. Once gas was in the tank it ran as a normal hybrid again.
 

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My hybrid battery was at 100% so the underhood 12v battery is not regularly maintained by the hybrid battery. In another thread about whether a separate 12v battery tender is needed for long term storage while the hybrid is plugged in, someone mentioned that the 4xe will enter into a ‘12v battery maintenance mode’ every three weeks so a separate tender is not needed. (I would confirm this through Jeep or some other source prior to relying on this for long term storage). This is great but not something that happens automatically on a daily basis so a bad or otherwise depleted 12v starter battery will strand you even if you have a charge on the 400v hybrid batteries. It might be nice to have a manual ‘jump start mode’ if this happens on the trail or a mechanical bypass switch that provides an alternate 12v supply from the hybrid batteries as a backup. These switches are common on RV’s and boats to allow using available battery sources to start a motor.
 

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I carry one of these in each of my plug in vehicles. They have plenty of power to wake up the computer modules and close the contactors to the HVB and then the car should start. This has saves my bacon twice already. (y)

 

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Discussion Starter · #12 ·
Good to know. You are probably the first person to go through this. I figured the computer would have detected the voltage getting low and try to save itself. But if there is a short that could make things worse.

Any idea what took the battery out?
 

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Discussion Starter · #13 ·
I carry one of these in each of my plug in vehicles. They have plenty of power to wake up the computer modules and close the contactors to the HVB and then the car should start. This has saves my bacon twice already. (y)

I'm going to order one since I'll be out in the woods soon.
 

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Good to know. You are probably the first person to go through this. I figured the computer would have detected the voltage getting low and try to save itself. But if there is a short that could make things worse.

Any idea what took the battery out?
Yeah, the manufactures all say "Don't worry, the days of a flat 12v battery are over. The system monitors the LVB voltage and maintains it with the HVB. Plus we send you alerts to your mobile app and in the car that gives you about a week or two notice that the LVB is failing."

Well, that sounds nice bit in reality people get stranded just like in an ICE vehicle. 12v batteries fail eventually. No avoiding it.

The first occurrence was my brother's Focus Electric the day he bought it. It was sold new but had been on the lot for 18 months. Just like everything else, these things need to see regular use or the 12v will degrade.

The second occurrence was with my wife's C-Max Energi last fall. That LVB had been replaced 4 years earlier so it was way overdue for a change.

Several friends on then Mach-E forum experienced dead LVB in their first week after delivery. It was almost an epidemic. Getting into those cars when the 12v dies is a complicated process. Our Jeep 4xes are super easy by comparison. :)
 
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