2016 Jeep Grand Cherokee - 60k mi - 3.6L auto - stuck in limp mode/accel pedal issue


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Error code P2127 - Throttle sensor switch E low input

So my wife's jeep just randomly went into limp mode and wont go over 40mph. Yesterday it was running just fine, no issues at all. When I ran the code it looks like the throttle sensor is getting inconsistent power or bad signals. Per a mechanic's advice I replaced the whole accelerator assembly/sensor and cleared the codes but I am still getting the same lights and its still in limp mode. The next suggestion was replacing the throttle body but I'm hesitant to keep changing parts out.

Does anyone here have experience with this? We're pretty broke so I'm willing to keep working on it as long as I'm not risking permanently f***ing it up. My main experience with vehicle repair just operator-level shit in the army (on tracked vics) so I'm competent but not a pro.

Any advice is appreciated. Please let me know if more info is needed.


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Not me. My sister in law has a 2016 geand cherokee too and its had a pretty fair number of issues. Yours is not one though
2016 patriot had some issues where both were changed over 2 different issues.

First make sure battery is good. All connections are clean no corrosion. And point of ground connections to the engine and body are clean and polished.

Bad battery and grounds throw many bad codes.

Then did you do the reset/relearn for the new accelerator?
Without the relearn the PCM may not know the new resistance readings and keep you in limp mode.

Never look down on anyone unless you are helping them up - Jesse Jackson
Thanks for the reply, I had the battery checked by one shop and autozone and they both said it was good (I replaced those about a year and change ago).

As for resetting the accelerator, I followed a few different videos and nothing seemed to work so far. The recommendations so far had to do with pressing the pedal 3 times while the car is in "Run" with the engine off but no luck. Is there a correct way to do that? I'm following youtube videos right now so any real info would be very appreciated.

If I recall there was something wierd like turn headlights on and off? im still looking but the below are harmless to try.

Try this:

1. Turn off all accessories
2. Insert key and turn to "ON" (Not Start)
3. Wait for the "DING" to depress throttle to the floor fully until check engine light flashes
4. Hold until CEL stops flashing
5. Turn key to "OFF"
6. Release throttle
7. Wait 2 minutes before start-up

Or this:

Turn key , but dont fire engine, wait for any lights that are going to go out-go out. Depress Acc. pedal to flow to the count of 10...Release pedal back up to count of 10. Turn off Key...Wait for 1 minute , & start car as normal--

Never look down on anyone unless you are helping them up - Jesse Jackson
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