1996 XJS 4.0 Jumping out of OD

Looking to buy a Car but the owner says it jumps out of OD when driving had Brand new trans installed doe’s the same thing

Not familiar with this system.

Genericaly, it is more than likely in the OD control system. Factors tell the transmission to down shift.

I got a Code P1333 which is the knock sensor i think what was happening is the car was just going into limp mode due to this code .

Is there an easier way to change out the Knock sensor I can only feel it on the front I cannot even do that? do I have to take the intake man off?

I’ve not replaced either of them, however they do use a shielded wire. Things can go sideways if that car loses it shielding….

If you find yourself removing the intake manifold, make sure you replace the manifold gasket and, while you’re there, the b%]+}^ hose.

Mark, are you referring to a Manual or Auto

Its an automatic. I think it is going into Limp mode due to a bad Knock sensor which It kicked a code for

I didn’t think our ZF24 trannys HAD an “overdrive” … Just 4 straight gears … ? :confused:

pretty sure it is going into limp mode

Well, Test drive it was dropping in and out of high gear downshifting in and out of high gear. Cked fluid lever it is right up to the mark ./Engine is misfiring though I am going to change the plugs tomorrow,see if that helps. I did get a code of the clutch solenoid though I am hoping that is not it the thought of having int to crawl up underneath this car and drop the pan doesn’t appeal to me.

If you got code P0758 then you can standby, I have my 96 XJS at a trusted transmission shop.

Will share results….


Got a call from the shop this morning. They checked the solenoids and associated wiring, apparently it all checked out. They are going to test the Transmission ECU now… at least thats a cheap part.

I just tested mine again it is harsh shifting and dropping in and out of low and high constantly. I am going to swap modules with the other 96 car to ck it out

I cked all the fuses all good however I noticed my Altenator had given up the ghost I wonder if the low voltage is affecting the Trans computer? Hummm

Quick note the trans seems to make a whining noise like a turbine when driving, Note this is supposed to be a new or another transmission, from what I can see it is a used one at that .

BINGO!! The engine misses. Power is down. computer senses shifts down out of OD. Fix the miss. Restore power.
engine can “pull” OD!!!

Back a bit. I had a n 85 F150 4X4 302 power. First of the EFI trucks. big tires. Would pull OD on level road. At any hill, it would shift down. Entirely proper.

Think of a stick shift. Not enought o climb the hill? Shift down…


I am getting a ABS warning light as well I was thinking my problem may be speed sensor-related after all. I have harsh shifting and erratic shifting as well.