Hi to all,

Have joined the forum in the hope to diagnose and hopefully assist anyone else if possible in attaining more knowledge of these great cars!. Have owned mine for two years now and had very little in the way of faults until recently and out of the blue.
My 05 plate 3.0v6 sport just started with one morning try to release the epb and then all hell broke loose Anyway eventually after disconnecting the battery it did release and prompted calibrate on the dash with no issues! That is until i drove it and then restricted performance and associated faults epb, cruise not available and amber light plus engine check light. Gearbox is clunking in and out of gears and seems confused. To cut a long story short i have replaced both rear abs sensors and also calliper slider pins as both sides were sticking. Have checked the battery and it is fully charged and upto power of 12.6 engine off off and left overnight. The car has 80k on the clock so purchased the zf auto trans service kit. On emptying the trans only 3.7 ltrs were removed? Now i know this to be low so searched for obvious leaks and nothing apart from wetness around the mechatronics sleeve and inside the plug seemed dry so unsure if this is the problem as yet. Have read fault codes and on deleting old codes and going for a run have retrieved the following p1643, u2522 and uo1o1 all pointing to loss of coms between tcm and ecm so now at a loss of what it could be doing. On further investigation reading countless posts jag and bmw related leads me to believe maybe the mechatronics rubber seals are suspect which i have bought also or causing loss of oil pressure in the trans once warm or faulty wiring linking the trans and engine modules. I know nothing is conclusive until i have replaced oil, seals and sleeve but is very confusing getting to how and why with this. Any input would be most grateful as all i see at this time is spending good money after bad on maybe's

 

Step one would be to look further into the condition of your battery; 12.6 volts is still a bit low. Then troubleshoot from there.

 

+1 on that! With so many faults suddenly appearing all at once, there must be some common root cause.

Have you seen this? I take it you have, as you mentioned the magic 12.6v limit:

https://www.jaguarforums.com/forum/s...faults-193787/

Please keep in mind that 12.6v is a VERY high standard, well above what most cars require. For some free troubleshooting, hook up an automatic battery charger overnight for a week or so. If the car now behaves, you'd know low prestart voltage was the culprit and could troubleshoot accordingly.

 

4 quarts out is normal unless you wait a long time

if the mechatronic adapter cracks the car will kick itself out of reverse and drive. the 4 tube seals never cause any trouble.

weak or clogged solenoids cause long shift adapt values. regardless of maintenance eventually the stator bushing wears and smokes the overdrive clutch but at 80k you’ve got a long way to go

 

Appreciate your reply although the battery was new last year it only really dose 15 to 20mile runs maybe twice a week and weekends! the battery was a and is showing full charge when trying to charge? Could this be a false reading then?

 

The leaking sleeve on the back of the transmission could be the source of your problems too? I did not see where you have replaced it yet?
We have seen several cars where this leak allowed transmission fluid to migrate up the wires and wire harness causing electrical problems. Which might be the source of your TCM to ECU communication problems.

From my experience with 6 speed ZF transmission you were pretty low on fluid too. If I leave it drain all night I can get 6.5 to 7L out of the 6 speed ZF.
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Yes have also read about such an issue with migrating fluid. The sleeve has not been changed as yet and neither has the rubber seals as the sump is original and has the small bolts of which are not going to be removed easily i know so was making a tool to remove these which i have now so will mean dropping the oil again but not a problem. Have also removed the battery now and checked cold it is at 12.2v so not good? will charge over night but battery meter still in the green and the charger is registering full charge.

 

That reading is very low. Not sure why your charger is saying otherwise. What brand/model charger are you using?

You had mentioned the battery was only a year old. It may be fine, just in need of a good charge. Your infrequent driving pattern can leave the battery never quite fully topped off. And if the charging system is not quite up to snuff, that will compound the problem.

I could be barking up the wrong tree, but it's easy to eliminate low prestart voltage as a cause by doing the battery charger routine every night for a week or so. I get it, it is a nuisance to connect the charger repeatedly like that. But it's also free and doesn't involve any hard work. And it could tell you a lot about which direction to proceed to fix the problem.

Are you back to driving the car yet? You had mentioned new wheel speed sensors and cleaning up the calipers? Did that have any effect or did the faults continue?

I can't tell you if and how those faults are tied to the transmission. If related, It may a chicken/egg thing of trying to determine which came first. But if the car is driveable, I'd be willing to gamble your reputation on the battery charger approach and see what happens.

 

Thanks Carl, well ive got the battery on charge anyway and checked it after 3 hrs and showed 12.8v so wondering if i remove charger for the night and check the voltage in the morning and what it loses. Using a simple 4amp mains auto charger and checking voltage with volt meter. No ive not been using the car as it will start and drive fine for a short while maybe a few miles then the faults light up again and gearbox goes into limp mode! if you turn it off it sometimes wont turn over and locks the gear lever in P. And after numerous attempts will restart and drive in third or very intermittent with clunks etc. Very strange behaviour when from cold drives and changes normal? This is what is doing my head right in to be honest as fault codes read one thing and gearbox is doing something else. Love this car but the computer management just defies logic for an old school motors.

 

Even better, what I’m suggesting is leave the charger on all night. That way, you’ve got a fully charged battery in the morning. See how the car behaves then. Maybe the transmission fault will remain and leave the car undriveable, but hopefully the other faults will go away.

If there is a drain running down the battery overnight, you can worry about isolating that later. Seeing the response to a fully charged battery in the morning will help determine what to do next.

 

Yes will do that and update tomorrow Karl. Appreciate your input on this.

 

Nothing like punching yourself in the face!!!!! I will explain, i had read the battery charger wrong last night and this morning realised that the readout works in the opposite direction? Yes i wear glasses lol. Anyway looks like the battery is taking more charge than i thought it needed so now hoping that this may solve a heap of issues and if im lucky all of them. Have been so engrossed in the problem that sometimes the obvious becomes invisible due to frustration i guess and the thought of chucking more cash at it. Anyway will update later on my results once the battery has been reinstalled and the car driven. Worse thing is i have been working on cars most of my life and saved myself a fortune in doing so! that is until i bought the jag. What a learning curve to realise newer cars are built to get you back to the dealer as opposed to helping you solve problems.

 

A few random thoughts, offered for free and worth every penny.

It kinda sounds like your charger isn't charging or your battery is kaput. I'd think after running overnight, all but a severely depleted battery would be good to go. Does the charger have any automatic features? Some chargers can be finicky about charging a battery that is run way down. I have an automatic charger but sometimes it goes into this funky protective mode. I have to manually hold an override button for a few seconds before it decides to start.

Another thought is 4 amps may not be enough. A battery is a mysterious chemical device that stores and releases energy. Sometimes you need a strong inrush of current to kick start the charging/storage process. I don't really know all the specifics, but it has something to do with the chemical reaction reaching the whole thickness of the plates. A weak charging rate only reaches the surface of the plates, a shallow charge so to speak.

To check your charger, leave it connected and put a voltmeter on the battery terminals. You should see around 13.75 - 14.5 volts. If less, it means either the charging rate is too low or the battery is in poor health.

 

No its fine Karl, i have two chargers and would rather slow charge as the battery has never been charged since new! less chance of twisting the plates as opposed to a fast charge. Have already checked the charge rate connected and is fine and tonight i removed it and checked battery voltage to be showing 14,09 then again a hour later it is at 13,20 and now this morning 13,10 which could well be good im not sure but that is cold not connected. Not convinced the battery is ok yet until i test on the car after a good run hopefully but will buy another anyway. Just hoping its the answer to the problems

 

That sounds to include "surface charge" (web search!) i.e. is not a useful reading.

Give it a decent load (headlamps, engine off of course) for 5 mins and see what it is then.

 

The battery is not on the car as yet but would it not be better to run the car then take a reading after with the engine off for an hour or so? Im no battery expert but i do need to know what is causing the faults so would do as you suggested not discharge the battery very quickly thus not leaving enough charge to find out what is really happening with regards to the fault codes i am getting.

 

Careful there. A battery is an expensive item to replace on a whim.

My thoughts are to keep the battery on the charger until the last minute before you drive away. That way it will have the fullest possible charge. (For the moment, don’t worry about the voltage dropping off at rest.) With any luck, the car will now behave itself and you’ll know you’re on the right track.

If the faults continue, your battery and charging system are probably fine. You’ll need to dig deeper elsewhere.

 

This is exactly my thoughts karl, i need another battery anyway of the same power for my van so either way it will get used although right enough they are definitely not cheap.

 

Ok so put on the car and did the epb reset as prompted! everything fine so started the car and no faults apart from engine light assuming it will go out anyway if everything checks out. Put into drive and faults came back straight away without even moving out of driveway? Switched car off and restarted faults still there so thought maybe drive it and see if they go away but wouldnt let me take it out of park. Switched car off then tried to restart and nothing? So removed battery again and test with multimeter at 12.9 volts after 3 starts. Im doubting it is the battery

 

Agreed. Not sure how this turned into a 3-day marathon, though. The general idea was to try the battery charger trick (basically a Hail Mary!) and see if that helped, and it didn't.

Not sure what to suggest next, but you'll want to retrieve any fault codes and go from there.