Limp mode: what to check?

[Don Bulee]

okay, I'm getting out of ideas.... there has been a few times my 06 rubicon with the 42rle get stuck in 2nd gear, I turned my jeep off and on and it was good to go... a few weeks my jeep got stuck in second gear again but now I haven't been able to get it out of the limp mode.... the oil was clean and its barely 80K miles,.. so I took it to an electric shop, the guy mentioned that all the wiring was good and the harnesses were just fine... by his advice and the guy from the tranny shop.. I got a new PCM from @Wranglerfix but that didn't solve the problem... I ordered as well a new solenoid pack from ebay (mopar), but that didn't solve the problem.... so... after the new installs I have a set of new codes....

P0700 - TRANSMISSION CONTROL SYSTEM (MIL REQUEST)
P0750 - LR SOLENOID CIRCUIT
P0562 - BATTERY VOLTAGE LOW
P0706 - CHECK SHIFTER SIGNAL

do anybody know what would be the next step??? I'm out of ideas...... tomorrow I'll take to the electric shop again to follow the wiring looking for a bad insulation or something like that... but... any ideas on what to check next???? I'm getting tired of this.... its like throwing darts in the dark... and expensive darts....

 

[D's Jeep Wrld]

Check the ground on the firewall,its by the cowl close to where the 3 big connectors are at
I was stuck in 2nd gear cause of my ground being off when I reloomed my wiring ,clean it tighten it up and see what that nets you

 

[John Cooper]

Check your tranmission harness. I found a rubbed wire on the passenger side above the sensor. That solved my problem. It's not easy or something that can be done quickly.

I had to basically run my fingers over every wire on both sides of the Tranny!!

 

[AaronPaul]

Solenoid Pack or Shift Selector Switch Issue. Given the P0750 and P0706 codes, the issue likely lies with the solenoid pack or the shift selector switch. The solenoid pack could be faulty or improperly installed, even if it’s new, or the shift selector may not be sending the correct signal to the TCM, causing limp mode.

Grounding Issue A poor ground connection can cause erratic behavior in the transmission control system. Check the grounds for the PCM, TCM, solenoids, and shift selector switch. Corrosion or loose connections here could lead to electrical issues affecting the transmission’s performance. Clean and verify all ground points for a solid connection.

 

[TheBoogieman]

The blue pill does wonders for "limp mode". @John Cooper told me so. BB says it ain't so.

 

[John Cooper]

The blue pill does wonders for "limp mode". @John Cooper told me so. BB says it ain't so.

Now hold on!!!!!! That little blue pill jump starts BB every time!!!!