• Welcome to the new NAXJA Forum! If your password does not work, please use "Forgot your password?" link on the log-in page. Please feel free to reach out to [email protected] if we can provide any assistance.

Transmission issues

tmp6

NAXJA Forum User
Hello, some quick info about my XJ first:
98 XJ Sport
4.0L
Auto Transmission

Starting about a month ago, I have experienced an issue with what I suspect to be a faulty electrical component of my transmission.
The symptoms are as follows:
- While the car is in drive, when taking off from a stop, the car feels as though it is in neutral and will barely move forward.
- However, when the car is brought up to normal cruising speed (~30 mph), nothing feels out of the normal expect maybe a slight decrease in power.
- Sometimes the car is like this from the moment it starts up, sometimes this happens in the middle of drives.

I recently figured out that when this phenomenon occurs, the car will operate normally when manually shifted into the 1-2 gear and continuing to shift up manually (3 -> D). This is why I assume electrical issues.

The check engine codes that have been thrown are as follows:
P0700 (Transmission Control System)
P0758 (Shift Solenoid B Electrical)
P0715 (Input/Turbine Speed Sensor A Circuit)

In an attempt to fix these issues I have:
- filled transmission fluid and made sure it was clean
- cleaned 3 electrical plugs located near the transmission fluid dipstick
- cleaned the electrical grounds that are responsible for the TCM and PCM located on the left side of the engine block

Despite this, the codes continue to throw after 5-10 minutes of driving (However, recently the P0700 code seems to have gone away).

Looking for any help/solutions to these issues.

Thank you
 
You should first try adjusting the TV (Kickdown) cable on the throttle body. Does your speedometer read correctly?

Skip ahead to 3:15 to see the TV cable adjustment. The vid continues on to test the solenoids. You'll need to view this on YT as it won't play on this page.

 
Test the shift solenoid resistances. Based on your symptoms, I'm willing to bet you have a bad shift solenoid A. If that's failing, it will try to start moving in 4th gear. Manually moving the shifter to 1-2 will force it to start in first. Also inspect the wiring to the transmission on the drivers side for any damage, including the wiring clamp wearing through the cable.

The shift solenoids can be replaced with the trans in the vehicle by dropping the pan. The set of all three solenoids is about $65 on Amazon. Don't overtighten the bolt that hold the pan on - moderately snug with a hand ratchet only so you don't trip the aluminum threads.
 
Problem solve for the Trouble Codes that are present. P0700 can be ignored at this time.

With a basic Google search you can locate an AW-4 Diagnostics and Service Manual.
 
My guess is either the solenoid, as per your code or one of the speed sensors. You can test the ohm of the solenoid from the connector up by the Transmisson dipstick. I forget if it is the gray or the black one.
 
A bad output speed sensor will cause it to not upshift out of 1st. A bad front sensor will just throw codes, sometime indicating the wrong solenoid.
 
Hey guys. I have a 1996 4wd Auto. here in the last month or so I have gotten a lot of the same symptoms. I will be saving this page and making my way down the thread and trying each "fix" in order they were posted. I will report back tomorrow and let you know if lubricating/ adjusting the kickdown cable works. I also will find a way to track my Mph and make sure my speedo is reading correctly.
 
Back
Top