gear box light will not go out, I have change the oil and still stuck in safe mode, when connected a OBD reader by British motors he cleared the fault in the ECU but the light was still there he told me that the gearbox as a CU and will need to be reset.

Can any help me how can I reset the gear box fault there are no faults in the ECU or codes I brought a wifi code reader which works on my phone and amazing bit of kit so much information from the car but it reads no faults and still the light is on. what next ?

Bear with me but exactly which light? Shape/symbol? And where?

The orange light which you will find on the rev counter, the shape is a tic tac shape.
in the display just under the light it says gearbox fault car is in safe mode which I do believe that's 2nd gear.

Check the handbook as I think you'll find that's the Engine malfunction light.

I guess you have an auto.

Changing the oil needs to be done properly, especially getting the level right. How sure are you it was done correctly, both with correct fluid and level? Also, at the right temperature?

If the light's on there are codes but for your (diesel) car it's possible a specialist reader will be needed. The OBD laws require powertrain problems be readable from the PCM so you SHOULD be able to read them with a generic OBD tool like an elm327 but the diesel uses a different PCM to all the other S-Types and I do not know if it follows the law. If somehow the fault is only in the TCM you'll definitely need a jag-type tool and may as well get a jag place read it. Make sure you get the code(s) and all the possible causes as many places are unhelpful to put it mildly.

2.7 twin turbo so yes the OBD 2 reader I HAVE DONT WORK,
I will ring Jaguar.
I have ordered a new OBD 2 reader which will work with the gear box tried and tested by jaguar forum on the 2004 s type.

GOOD DAY

Hi all .
unfortunately & with a heavy sad heart , my S type 4.2 V8 is off to we buy any car .com tomorrow.

all due to “” gear box fault “” issues .
I’ve simply had enough & spent enough .
1st bill ….£1800.. gear box re build .
lasted just over a week .,

2nd bill ..,£499 valve body testing & two new solonoids

today rough shifting , gear box fault on dash ,, stuck in 3 rd gear etc .

its been going on for weeks & £2300 spent plus taxi fares etc .. u have to in the end draw a line ..

the car is 20 years old & enough is enough .

it most likely needs a new mechatronic valve body ( more ££££ ) the car isn’t worth it