Pbudi

I have a 2009 Jeep jk 2 door with an automatic transmission and it only has 80,000 miles on it. I was having issues earlier this year with the transmittion slipping into neutral and the upshifts being very rough after being driven for alittle bit so I changed the transmission fluid and it seemed to work fine but it’s back and I’m experiencing the same issue. Also on cold starts there is a very loud scraping noise coming from the tranny whether it’s in reverse or drive it still makes it until about 5 minutes of driving then it goes away. I am also able to smell a burning scent coming front the transmission after about 20 minutes of driving drivingAny thoughts on what this could be?

ronjenx

That doesn't sound good, but let's start with a few easy questions.
Are you the original owner?
What are you running for transmission fluid?
Do you check the fluid level with the engine idling?
Have you had any warning lights come on, then had it scanned for codes?

Sounds like it has been overheated too many times.

Pbudi

I am not the original owner and as far as what fluid I’m using I honesty don’t know my shop ended up changing it for me. And all fluid levels look fine: today a check engine light did come on after only driving for 10 minutes. The codes are P0513, P0731 and p0868. That’s a lot of codes😬

Rednroll

If it's any help.

Code P0513 = an invalid skim key. (Sentry Key Imobilizer Module)

Code P0731= Powertrain Computer or PCM is seeing greater than a specified RPM difference between the rotational speed of the Input RPM Sensor and the Transmission Output RPM Sensor in Gear 1

Code P0868= Generic OBD-II code that detects a problem with the transmission fluid pressure. When the powertrain control module (PCM) detects that the pressure of the transmission fluid is either too high or too low, the P0868 trouble code will be triggered.

I would definitely check the trans fluid level to eliminate that as a potential cause. It's always a good idea to double check the work a shop has done. Too much trans fluid can often be worse than too little.

Also another trans fluid change may help as well. When they change the trans fluid, not all fluid is removed. Seeing as though it sounded like the problem went away and then came back again after they changed the fluid, that may be an indication that the old and new fluid eventually got mixed together and caused the problem to show again. Another trans fluid change would help remove more of the old fluid that was left behind.

Rednroll

The P0731 seems troublesome, where that's an indication that the trans may be slipping and the fact that you smelled burning would be a further indication of clutch gears getting burnt.

Common Problems That Trigger the P0731 Code

• Defective Gear 1 Shift Solenoid
• Defective Forward Clutch
• Defective Engine Coolant Temperature Sensor
• Defective Valve Body
• Dirty transmission fluid that restricts the hydraulic passages

Diagnostic & Repair Steps:

Always be sure to check fluid level and condition before proceeding with further diagnosis. Improper fluid level or dirty fluid can may cause shifting issues that affect multiple gears. If only one incorrect ratio code is being displayed, test drive the vehicle to determine if the gear is actually working. The transmission internal clutches and bands are usually controlled by a solenoid or using fluid pressure. If there is an electrical issue with a shift solenoid, a code specific to that fault should also be displayed. Correct the electrical issue before proceeding further. Blocked fluid passage inside the transmission can also cause the vehicle to not start out in 1st gear, if there are multiple incorrect ratio codes but the transmission performs as expected, there could be a mechanical issue with the torque converter, transmission main control, or pressure problems. If there are multiple incorrect ratio codes and shift issues, but not all are displayed the fault may be a mechanical issue internal to the transmission, or a fluid pressure / blocked passage in the main control. A shift solenoid that controls multiple gears can also be at fault if there is an internal blockage or fluid pressure problem. If there is an electrical problem with the solenoid that controls the gears, a code should be displayed specific to the solenoid at fault. It may be necessary to use an advanced diagnostics scan tool to determine which gear is being commanded by the transmission, and to determine if the engine speed matches with the calculated output speed from the transmission sensor. Advanced knowledge of transmission operation and overhaul is often required to repair this type of malfunction. Consult the factory service manual for vehicle specific diagnostic procedures.

Read more at: https://www.obd-codes.com/p0731



Here's a 42RLE trans tear down, unfortunately you may have a similar problem but at least this gives some explanation of what may have happened.