03Laredo

Hi all and what a great forum! I have an 03 WJ Laredo 4.0 4wd. I had the transmission go into limp mode, p0748. My transmission guy replaced the solenoid and transducer, with mopar parts.I have been fine up until about a week ago. I did a reset of the computer and it takes no time to pop up again. I had heard that an o2 sensor failure can also throw this code due to a shared ground. Could the o2 relay also cause this issue? I am at a loss here! Putting new 02 sensors in to test the theory. If anyone has had this issue please let me know how it was resolved! Thanks in advance!

03Laredo

Has no one had this issue?

Bugout4x4

Possible causes Dirty transmission fluid Low transmission fluid level, Faulty governor pressure solenoid valve Governor pressure, solenoid valve harness or connectors, Governor pressure solenoid valve circuit is open or shorted.

Tech notes...When a transmission solenoid is malfunctioned, in most cases the problem is not the electrical part of the solenoid; the problem is foreign material obstructing the mechanical function of the solenoid or the flow of the fluid through the transmission valve body. If the transmission fluid is dirty, it's recommended to change the transmission fluid and if possible removing the transmission pan for further diagnosis. Excessive debris or metal particles on the transmission pan could be an indication that there is a mechanical transmission failure and that the transmission will need to be rebuilt or replaced.

When is the code detected? Engine Control Module (ECM) detectes an open or shorted condition on the solenoid circuit. Possible symptoms... Engine Light ON (or Service Engine Soon Warning Light), Transmission shift shock.

P0748 Jeep Description...The Pressure Control (PC) Solenoid Valve an electronic pressure regulator that controls transmission line pressure based on current flow through its coil windings. As current flow is increased, the magnetic field produced by the coil moves the solenoid’s plunger further away from the exhaust port. Opening the exhaust port decreases the output fluid pressure regulated by the PC solenoid valve, which ultimately decreases line pressure. The line pressure solenoid valve regulates the oil pump discharge pressure to suit the driving condition in response to a signal sent from the Transmission Control Module (TCM).

Read more: https://www.engine-codes.com/p0748_jeep.html

jdmartin

So this is over a year old but I currently have a similar issue. It all started when my O2 sensor got tangled up in my drive shaft which shorted out and blew a main fuse (vehicle just died). Once I replaced the fuse (cut off the O2 sensor) it started up again but now I'm stuck in limp mode so maybe there some link between the TCU and O2 sensors!! Still have the issue but I just drive it in auto stick mode for now, but going to see if a tranny shop can reprogram the unit.

Just witness

My 42re is in limp mode ever since the 02 sensor was tangled in the drive shaft. Wires didn't get mangeled. Changed the governor pressure sensor and solenoid twice still didn't fix code. Replaced the ECM. Car has been out of commission 6 months +. Did anyone figure this out? What about a new 52118500AB ( wiring harness that goes in transmission that plugs into the governor pressure sensor and solenoid )