Hello. I joined this forum because I own a 2004 Jaguar XType3.0 Automatic and have been reading on this forum for some time trying to fix a gearbox fault issue. It all started in a horrible downpour rainstorm. I was at a stop with my foot on the brake and it was jolting in and out of gears so bad I had to press down hard to keep it from moving. So, TCM was soaked. Yes I replaced my TCM and have sealed it. I have spent lots of money and time on the issue for months and nothing seems to fix it. I am at a loss and although I come from a long line of mechanics amd work on my own cars. I am considering going to Jagaur dealership. They want hundreds to try to diagnose. I am very sad. I love this car. My gearbox fault is, engine light, gearbox fault, stuck in what seems 4th gear when I put it in drive although sometimes I have no gearbox fault and it just really hard shifts. I have cruise control and sport available. I have removed the ECU and inspected both sides, no water damage. I now have a scratching noise from the cluster when I start and turn off the car. I have replaced spark plugs, manifold gaskets, oil and filter, transmission oil, TCM, radiator hose, thermostat and housing, air intake hose, air filter,...off the top of my head. I may be forgetting something. My battery date is 11/17 but each time I've run test menu I get 11.8V. Whether its cold or been run for an hour. Thank you for any advice.

 

I know when I joined, it seemed every freaking problem was met with "load test the battery". Not the AutoZone crap one, but the 30-45 minute in-car one (luckily my local Wal-Mart has a machine = very $$$ to own).

Now a couple of years later, immense research here and on the WEB, I know how finicky these cars are for voltage change. I was having some intermittent problems and the "sound" from the cluster was the beginning. It sounded the same as when you enter cluster test mode and do the gauge test. It sounds sort of like a cheap plastic gear stripping.

Soon after the battery was fine night I parked it, completely dead the next morning.

Your description sounds kinda like that "funny sound" from the cluster. Get it in-car load tested and take it from there.

 

Also there have been a fair amount of reports that drivers hit a pot hole hard and had this problem. The ECM had to be replaced. I think it could be broken solder points that could be repaired instead of replacing. There is a thread here with pics and directions on an ECM rebuild that can guide you opening it up. One post on water egress into transmission (reported?), and the wiring of transmission that was fixed with sealant and waterproofing the wires.

 

I appreciate your response. I was thinking battery next. My understanding is that if a 12 volt battery tests 12 volts or lower it is considered dead. I have to tell you that yesterday, I took it out and it was in gearbox fault. I left it parked outside, and until this point I have kept it covered and dry. Well a quick heavy rain hit for about 20 minutes and when I got it it to pull it in the garage, there was no gearbox fault, I drove it around for 30 minutes and it drove great. Today hot and dry.... gearbox fault. Possibly and electrical shortage of some sort??? I interned for a Dr years back who had humidifiers running in his office because he had computer problems due to our extremely dry climate here. I unfortunately do not understand motherboards or computers very well. Also, I have been wanting to change my headlight bulbs because someone put blue LED bulbs in them and I am not a fan. When I looked at the bulbs, they are wired in with 2 wires and the other 2 wires are left hanging. There is no attachment or plug on either the bulbs or the car wires.The black cover caps(under the hood) are missing as well. I also own a 2nd 2004 Jaguar X type, basically same car but it is a 5 speed manual and never a problem with that one and it has been in the same conditions as the other, I have not put any work in to it as it has never had a problem and my manual has demanded all of my spare attention.

 

There are tables e.g. https://www.energymatters.com.au/com...age-discharge/

12V is about 25% of full and will drop alarmingly under load. The computers hate that.