Hello,

As soon as my XJ8 has been standing still with motor off for more that 3-4 course, she plays up and needs a trick to start: start engine, get fault massage. Shut motor off, start again, put very slowly in reverse, she will reverse with a jolt. Then put in drive and let her roll a couple of meters, Repeat this 2-5 times and all will be normal again. BUT, after some Km, i get a new message, lose engine braking. The I stop where i can, shut motor off and re-start. Problem gone. May re-occur a couple of times till motor normal temperature.

Any ideas, anyone ?

Thanks.

 

P0706 GEARBOX FAULT

Rotary switch and/or D – 4 switch malfunction

When fault is detected:
– TCM adopts transmission
mechanical limp home mode
(4th gear)
– ECM limits engine power

Possible Causes
Transmission to TCM harness
(TCM pins 52, 53) open circuit, short circuit
or high resistance
TCM failure

 

Thanks, I will check that !


Takeo

 

Funny thing is that all the faults seem to disappear after the engine is warm and driven for like 50-60 Kim.

Also get, at the same time, engine coolant low warnings that come and go ...




Takeo.

 

So, once it warms up, problems go away? I would check the temperature sensor in the cross over pipe; also the connections of that sensor to the MAF (bent prongs, broken wires). The car is not being correctly enriched (choked in the old days) for starting, but once warm runs fine.

But have your servicing technician check for Bob's errors first . . . more likely

 

Thank you for the advice, but a small problem here: the closest Jaguar guy is to be found about 50 Km from here. When I call, all say my car is too old do do anything about it and that they dont have the fault finding CD anymore.

Also, Jag dealers here ask for like 100 Euro a hour, even to look at your car without opening the hood.

The may be some knowledgeable guy around Paris or Lyon or wherever but that is at least 500 K from here. LOL.

Local garage is an agricultural tractor specialist. I live in the south of France, yes, in the damned middle of nowhere.

 

Does the cam plate on the selector lever housing rotate correctly with the lever?
Is the D4 switch (or plastic cam plate) broken or damaged?

 

Very good question as soon as I can (I am an invalid) I will try to find that out, I have seen a vid on yutube of a man taking the all upper part off and putting a cam plate in there, plate was missing.

Thank you

Takeo.

 

Hello,

While using some unprintable words, swearwords and also singing psalms, I got to the disk and the little microswitch. All looked in perfect condition !

So I took her for some 20 Km stop-and-go, shifting up and down, widely variable speeds but had the problem again 3 times while shifting DOWN, it never occurs while shifting UP.

Procedure: stop where I can, switch motor off and back on and the problem is gone !!! So silly.

Stationary, at home, I could switch engine contact on and off without one single error on the lire screen.

Usually, in mornings, contact on and I get the sill gearbox full immediately. Then I shut engine off, start it again and switch to reverse, which results in a very brutal "KLONK" shift. I shift to drive and get the same "KLONK". After that, 2 - 3 timess motor on and off and the problme is gone.

NOW, i still get/got the silly mentions but the gearshift R and D feel normal , no more KLONKS.

So I think it might be an electric / electronic problem somewhere ????


Thank you for your help !

Takeo.

 

A “very brutal KLONK” sounds just like a broken forward clutch drum.
Just my 2 francs worth.

 

Hello,

The brutal klonk only occurs if shift into reverse with brake pedal pushed in, if i let go of the brake pedal and then sloooooowly shift into R, there is only a harsh shift, same for back in D. Repeat 2-3 times in the morning and all goes to normal. For the first 50 Km, expect "gearbox fault" 2 or 3 times. Stop, switch engine off and back on and all is normal again..... someone please explain lol.

Not funny, really, the klonk problem is when she had stood still for some 3-4 hours, warm or cold.

New gearbox installed 3 years ago.

Where is TCM located ? Some talk about a TCM fan, where can I check this fan ??


Thanks,

Takeo.

 

Hello, I located the TCM / ECM.


NO fan there !!!!!


Takeo.