2012 Grand Cherokee 5.7 Hemi

In Feb 2022 My jeep was running rough, I had Check Engine Lgt, Lightening Bold and a bunch of codes, most relating to Throttle Body and Acc Pedal. Sometimes I would lose power while driving, But I could pull over and wait a couple of minutes, then start back up and drive normal. Sometimes it would not start until about 5 or 6 tries. I took it in to shop and they replaced throttle body, accelerator, and a couple of sensors (crankshaft/oil pressure). When I picked up vehicle, it took 10 miles before my panel lit up and started running rough, just like when I took it in. I took it back to them, and they couldn't figure out what went wrong. They did the reset/relearn with their computer, and that did not help. They kept it for a couple of days, and it drove good for about 2 weeks, then same problems came back. They sold the shop, and I didn't have $$ to start all over, so I lived with my problems. It happened about once a month and resolved itself.

In November 2022 it started running rough, losing power, on a daily basis. I also had misfires on 1 cylandar, and a bad water pump. I took it to a new mechanic, described my issues, and he said since I used aftermarket parts the first time, that was most likely my problem, I bought mopar throttle body this time. I drove 20 minutes to this new shop, and had no problems getting vehicle to him. He put all new spark plugs, a coil for the one cylandar that was misfiring, repaced water pump, changed oil and installed new Mopar Throttle Body, He called the next day and said I would have to replace the Accelerator Pedal also, So I bought new Mopar Accelerator Pedal. After he installed the Accelerator Pedal, He called and said that it still was not running right, And the only thing he new was for me to get a new PCM. Basically told me to come pick up vehicle. He FAILED to mention that my Jeep had No Power, and Little Acceleration, So bad that all it would go was maybe 25 mph with pedal all the way depressed.. I had to tow vehicle home. Decided to bite the bullet and take it to a dealer, but they are 3-4 wks out for appts. I found a mechanic who has a good reputation and experience with Jeeps. That appt is 2 weeks out. Anybody had this issue, I have tried the manual reset/relearn procedures and they do not work. When I start it now, It is rough Idle, RPM is 1000 and does not change when accelerator pedal is depressed to the floor. Any ideas so I can at least get around while waitinf for my appt in 2 weeks.

 

Um, ...any trouble codes?

 

2135, 2138,0122, 0123 and I think a couple more related to Throttle Body.........When I picked up from shop this last time 2135, 2138

 

Seems to me these all point to the TPS, throttle position sensor. Is that part of the assembly you replaced? If it was an older jeep it would surely mean TPS.
So the question I have is, has the TPS been replaced (with a MOPAR).

 

On my 2012, You have to replace the throttle body. Yes it is Mopar

 

Admittedly I'm not up on these, per se, but I would lean to the accelerator pedal being the most correlated to the codes you have.
Also, if you go to RockAuto, look up a throttle body, and click on the Info tab of almost any one, they all seem to have a full page of descriptions on how to diagnose and repair. It wont let me copy a usable link and it's too big to copy and paste...

 

Thanks for the info. I have replaced the throttle body and accelerator pedal twice. First time used aftermarket, then replaced them with Mopar. I appreciate your help.

 

I feel your pain. I did watch one video where the guy had to do the relearn sequence, or whatever you call that, 5 times, then it worked. A lot to this.

 

Sometimes just a good careful slow look around and you can spot something not right.

 

Have you tried cleaning it? If you have a black buildup inside the throttle body it could be blocking the airflow that squeeks past the vents when it is closed. There is supposed to be a tiny bit of airflow there that gets blocked when you get a buildup there. Clean that up and it could solve your issue. I had almost 300,000 miles on mine and cleaning it made it drive like a whole new truck.

 

Good catch. I believe if you check the Factory Service Manual, or FSM as it's known, it does say to clean the throttle body at 300,000 miles.
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