2000 Jag S type 3.0 V6. ( the ford 5R55N auto box) 72000miles.
I was getting "gearbox fault" warning after 5 mins driving, and codes found were for incorrect gear ratios.
Found a replacement gearbox in good working order and fitted it . New filter and transmission fluid.
However the same fault has appeared again. After 5 minutes driving "gearbox fault " appears.
If you stop and start driving again the warning disappears for a few minutes and then re appears.
I don't know what my next move will be?
The only other strange thing was,- before the gearbox swap the cooling fan would come on as soon as the car started. After the gearbox swap it doesn't appear to come on at all and I have tried to induce it to come on .. This maybe the fan control module giving up ! I mention it in case someone feels it is significant as the fan draws air through the transmission oil cooler / power steering fluid radiator, as well as the engine coolant rad and the air con radiator.

Any advice gratefully received!

 

Don't know but without any codes posted it will be hard to say?
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+1

Also, engine faults (such as misfires) can upset the gearbox so concentrate on the engine next.

 

Thanks for your replies.
The car drives fine for 5-10 minutes and then "gearbox fault " message appears.
I had the Jaguar code read again to see what it came up with . This was after two 15 min drives which brought up the "gearbox fault" message.
There are no fault codes stored but several "PENDING CODES" , as follows

ECM engine control module ;- P1000 check of all OBD 2 systems incomplete since last memory clear.
P1572 brake pedal sensor out of self test range.

IPK instrument pack;- U 1073 SCP (J1850) invalid or missing data for engine coolant.
U 1262 SCP (J1850) communications bus fault.

CCM Climate Control Module;- U1073 SCP (J1850) invalid or missing data for the engine coolant.

MCC Message centre control module;- U1262 SCP (J1850) communications bus fault.

Any views on action needed would be gratefully received.

 

In the S-Type with 5R55N transmission, the engine control module is also doing the job of transmission control module.

The brake pedal switch fault could cause a transmission fault message & limp mode.

 

Thanks for your input.
I'll look at the brake pedal.
Some pointers to my problem.
The car runs fine, but after 5 minutes I get the Gearbox fault message. The gearbox then tends to stay in a low ratio rather than change up. If you stop switch off, switch on,.... the message is gone for another 5 minutes and the car seems to drive normally.
I'm not aware of going into limp mode. But on tickover after 2 runs today the car had developed a slight missfire .

 

I have discovered that the upper brake pedal switch which tells the ecu when the brakes are applied was not working. This has been repaired . The result is that moving the gearbox selector from park to reverse to drive has become very smooth indeed. This faulty switch may have caused the gearbox fault message to be produced.

When I have sorted the cooling fan issues I will test drive the car.