Fixing an unpredictable 4xe throttle response

[Bob D.]

I have a '24 Sahara 4xe purchased new in March 2025 and currently have just under 20,000 miles on it. In the last month, since it started to get cold in the northeast, the throttle has become episodically unpredictable. During an episode, it refuses to increase throttle response as you depress the throttle pedal. It sometimes even reduces throttle response when you don't lift off the throttle. In either case, if you further depress the throttle pedal without getting a response, after waiting a full second or so, it will suddenly jump to full throttle. Needless to say, this is not something you want to have happen in tight traffic, or in your driveway. Fortunately it always responds immediately to lifting off the throttle.

I asked my local dealer to look at it, but since the behavior is episodic and didn't happen when they drove it, and and they don't see any error codes, they said there is nothing they can do. You basically have to drive it every day for a week in order to see an episode. I've had the episodes happen in hybrid mode and in electric mode, but so far I haven't seen it happen in e-save mode (gas engine only). It often happens at startup, but can happen later as well. I've seen it happen at 9 degrees F. and at 50 degrees F.

Has anyone had a similar issue? If so, were you able to resolve it, and how?

Thanks,
Bob

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[lindaspins]

Max Regen on or off?

 

[Bob D.]

Good question! I have always had Max Regen on. I'll try keeping it off for a while and see what happens.

 

[BrianUNC]

When you're talking about this throttle behavior, is it happening when only under electric propulsion, and then when "fully jumping to full throttle" may be when it kicks on the gas engine? If so, there are a lot of 4xe owners who are experiencing this recently. I suspect it's related to recent updates (I noticed mine started doing it after a service appointment where they updated a few different modules, prior to the 68C recall appointment).

 

[lindaspins]

Good question! I have always had Max Regen on. I'll try keeping it off for a while and see what happens.

I've found it seems to behave better with Max Regen off. It's tricky to get used to the longer braking distance, though.
(I'll note that this has been a long term observation-we have not had the 68C recall completed yet, it's at the shop now).

 

[mjg4xe]

I also experience this in the Northeast once in awhile, but only when I am going uphill and in cold weather. I have to switch it over to e-save to get the engine to kick on, but ultimately will go on itself with the RPMs reving high at first to catch up with the power demand.

 

[morph860]

Does it only happen when the gas engine is cold and turning on for the first time? And then once the temp is up, it goes back to normal? If so, you can get the gas engine to turn on without needing to floor the gas pedal. Pull the shifter to the left and into "Manual mode". Engine should start up right away and then you can have more control over the temp.

 

[Bob D.]

When you're talking about this throttle behavior, is it happening when only under electric propulsion, and then when "fully jumping to full throttle" may be when it kicks on the gas engine? If so, there are a lot of 4xe owners who are experiencing this recently. I suspect it's related to recent updates (I noticed mine started doing it after a service appointment where they updated a few different modules, prior to the 68C recall appointment).

Lately it's been happening in Selec-Trac under electric propulsion and "jumping to full throttle" is when the gas engine engages at high RPM. But this has also happened in 4 LO with the gas engine engaged.

I'm not sure there is any relevance, but perhaps I should also add that I got bit by the over-the-air update leading to a complete loss of forward drive. But the nearest dealership reprogrammed the control units and I have not had that issue return. The current issue, with a short duration loss of throttle response, first occurred before that update.

 

[Bob D.]

Does it only happen when the gas engine is cold and turning on for the first time? And then once the temp is up, it goes back to normal? If so, you can get the gas engine to turn on without needing to floor the gas pedal. Pull the shifter to the left and into "Manual mode". Engine should start up right away and then you can have more control over the temp.

It's more likely when the gas engine is cold but it's not limited to that. I was afraid of using hybrid mode in dense Christmas shopping traffic so I kept it in e-save mode eventually ending up with an 80% charge in the high voltage battery. The next day I ran in electric mode trying to deplete the battery, but at multiple times the vehicle reduced throttle response without any change in input from me.

So far, driving in e-save mode seems to be the best work around for the problem, though it nullifies the utility of the 4xe. I'm taking it in for the 68C recall tomorrow, so maybe that will impact this issue in a positive way.

 

[Andy@AAV]

This occurs when the battery is unable to supply sufficient power to the motors. It can be caused by battery temperature that is too low or too high. I have experienced this when driving home on electric mode in the summer on a hill, and lately when leaving home without conditioning the battery when the temperature is in the teens. I’ve gotten to know when it will happen and I change modes to avoid it if I suspect it will occur.

 

[BrianUNC]

Not surprised and that makes total sense. I suspect some of the recent updates dialed in those guardrails a little more, making it happen more often. Shame the battery and motor are so under-specced that can happen.

 

[alphawolff]

I have a '24 Sahara 4xe purchased new in March 2025 and currently have just under 20,000 miles on it. In the last month, since it started to get cold in the northeast, the throttle has become episodically unpredictable. During an episode, it refuses to increase throttle response as you depress the throttle pedal. It sometimes even reduces throttle response when you don't lift off the throttle. In either case, if you further depress the throttle pedal without getting a response, after waiting a full second or so, it will suddenly jump to full throttle. Needless to say, this is not something you want to have happen in tight traffic, or in your driveway. Fortunately it always responds immediately to lifting off the throttle.

I asked my local dealer to look at it, but since the behavior is episodic and didn't happen when they drove it, and and they don't see any error codes, they said there is nothing they can do. You basically have to drive it every day for a week in order to see an episode. I've had the episodes happen in hybrid mode and in electric mode, but so far I haven't seen it happen in e-save mode (gas engine only). It often happens at startup, but can happen later as well. I've seen it happen at 9 degrees F. and at 50 degrees F.

Has anyone had a similar issue? If so, were you able to resolve it, and how?

Thanks,
Bob

I've heard this a few times, seems to be an issue with the most recent software levels. Nothing the dealer can really do about it

 

[Bob D.]

Thanks to all for the helpful responses. That gives me a much better idea on how to work around the problem ... when I get my Jeep back.

Two weeks ago I had the 68C recall done and my battery passed. A week later I got a "service charging system" message, took it in to the dealer, and found out I need a new high voltage battery!

 

[Wapiti]

I've had this throttle response issue a couple of times since doing the 68c recall the first week it was available. It happened tonight, and here's a few data points that might be helpful in figuring this out.
-I'm cheap, and my local Circle K had a 40 cents off deal today so I mostly ran on gas to burn off the old before fueling up with the cheap. Consequently, the engine was warm but I was now in Electric mode to save gas until I got home to charge.
-I slowed down to make a left turn off a highway in relatively heavy traffic. I don't know that I ever came to a complete stop, although I thought I did (this becomes important later).
-When I had a small gap I went for it but it never accelerated past a little above idle. A bit of a pucker factor, and I realized it was doing it again. I mashed the skinny pedal and the engine kicked in. Since I was in 4auto it got up and went- one of the benefits of the platform.
-I experimented by putting it back in Electric mode. At 45 mph or so there was no acceleration. I have my dash set to show what gear the tranny is in, and at that point it was in 4th. The power indicator (right side of the dash) did not seem to change with throttle input.
-A right turn came up so I decelerated but didn't stop. Same deal when I applied the throttle on exit, only this time the tranny was in 2nd gear.
-I was on a rural road with minimal traffic so I played around with it. Long story short, no throttle response so I would mash it into dino juice mode and then reset to to blue state mode.
-Here's the kicker- once I came to a complete stop and the tranny went back to 1st gear, it was fine.

So, is this a transmission problem? I don't have a hypothesis to explain how this is tied to the recall but the first time it happened was the day I picked it up afterwards. The big thing- no check engine light during any of this. @alphawolff ?

 

[BXFXJeep]

Usually when there is a throttle response issue, a failure of the high voltage battery soon follows.

Previous recalls it took months for the failure to get triggered after throttle issues, the 68C might trigger the failure earlier by shutting down the HV system to isolate the battery.

What have been reported, is the gas engine kicks in when it usually did not previously for the same kind of driving.

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