Bank 1 refers to the cylinders on one side of the engine. The V6 engine has two banks of three cylinders each. I'm having a brain fart trying to remember if bank 1 is the US driver's side or the US passenger's side.

P0171 is a very common code. Note the second digit is the number 0, not the letter O. If you search this forum for P0171 (or sister code P0174 for bank 2), you will see lots of info. This code isn't the end of the world. It's generally caused by a vacuum leak causing the fuel/air mix to become too lean. A few common places to look for leaks are here:

http://www.jagrepair.com/images/Auto...uul%20Leak.pdf


Two good articles on vacuum leak diagnostics are here:

JagRepair.com - Jaguar Repair Information Resource


Hope this doesn't seem too "hi-techie" for you. I'm not sure of your experience level, but there's no need to panic about that code. Take care of it yourself or have it done at a shop.




These transmissions can be serviced, but as you have discovered, there is no dipstick for checking and refilling. I'm assuming (Danger! Danger!) you'd prefer to have a shop do it. I'm not entirely sold on the transmission thump theory, but it certainly won't hurt to have the transmission serviced.

I'll get up on my soapbox for a minute. Many shops will try to sell you a transmission flush, but I'm very much against that. Due to normal wear and tear of the friction material in the transmission, expect some crud to settle out in the transmission pan. This stuff isn't harming anything sitting there. Run a flush service, though, and all that crap gets stirred up and recirculated. A tiny bit of crud in motion won't hurt anything, but the flush is like unleashing a tidal wave. I much prefer to leave the crud safely at the bottom of the pan, out of harm's way. If you'd prefer to get it out of there, have the shop drop the pan and clean it out that way. Have them change the filter while they're in there, too. [/soapbox mode off]




No, I don't really think so. Sounds like you've got two separate issues. One is the known lean condition in the engine (P0171 code) and the cause of the thump is still unknown, possibly the transmission but who knows.

If at all possible, I'd highly suggest working the two issues separately. I may catch some flak over this, but I don't think you're causing any harm driving carefully with the P0171 for a couple of weeks. The computer will do its best to compensate. IF the light starts flashing, yes, that is VERY bad, meaning you've got a problem bad enough to melt down a catalytic converter. In that case, stop driving immediately and pull over to the side of the road. For the light on steady, but NOT flashing? That means 'check engine soon', but there's no need to panic.

The reason I suggest working the problems separately? Say you take the car to the shop and they fix some vacuum leaks, service the transmission, and maybe throw some new spark plugs in there for good measure, too. After a few days, the car suddenly starts chugging. Is it the spark plugs? Was it a vacuum hose disturbed during the engine work? Maybe a gasket got folded over? Is it a problem with the transmission service? You can't tell if lots of work was done at the same time. That's why I like to recommend only fixing one problem at a time, and driving a little bit in between to verify nothing got worse.

 

Yeah he is talking about the same thing as I, a pump to transfer the ATF from or too the gearbox. I've just had the gearbox serviced on mine and it did make a significant improvement to its all round operation. I took it to an independent specialist Jaguar workshop. Gearbox service every 70k miles and it is not a "sealed for life" unit.

 

A vacuum leaks will cause the transmission to act up, possibly causing a thumping sound. I would get the P0171fixed then see how transmission feels.

 

Reference no local Jaguar workshop.
Assuming yours is the 6 speed gearbox as its an 03 model V6? The "6 speed automatic ZF" gearbox is common to several other premium brands including BMW, Audi, VW, Aston Martin, Range Rover, Maserati, Bentley, and others.
Therefore if you can find another car specialist in the ZF automatic gearbox they would an option for a gearbox service, subject to all the usual checks on any new workshop.

 

Quite.

Maybe OP isn't listening though?

 

The old saying, you can lead a horse to water....... Comes to mind to me.

 

Can I pick your brains for more details? Not doubting you, just curious how the two are connected.

I'm familiar with older automatic transmissions that had a vacuum modulator. The vacuum signal from the engine was used to interpret load on the transmission, and the shift points would be adjusted accordingly.

There's not an actual vacuum connection on the S-type, is there? From my limited way of thinking, I'd imagine the PCM uses throttle position, manifold pressure, and who knows what else to determine load. And if there was a vacuum leak bad enough to set a P0171 or P0174 code, wouldn't the PCM be smart enough to modify the engine load signal sent to the transmission?

Once again, not doubting you, just wondering how it's all deduced.

 

Karl,
Way, way back in 2009, I had to remove the plenum on our 3.0. There is a very tricky vacuum line on the back to remove. When I did finally removed the vacuum line, I messed up the brass fitting the line fits into causing a slight vacuum leak, which in turn caused a "kick feeling or thump" in the transmission as the vehicle was coming to a stop.
Two of the Techs on the forum told me I was in the MY range for a Transmission flash, when I explained the problem. I wasn't super convinced. I went back and "Rick rigged" the brass vacuum connector. I took Joyces Jag out for a ride, poof Bob's yer Uncle, no more kick/thump when coming to a stop.
I do not know how or the why this vacuum line (or any?) would affect the HP gearbox but it did on our vehicle. Somewhere here in the archives is what I am basing this shortened version off of. Some of the old time S Type owners may recall the discussions.




Below is the fitting I had to replace, it was the brake booster vacuum line fitting. Oddly enough, Wayne our local Jaguar Dealer Parts man of 25+ years had never sold one in his career, but he had it in stock!

 

The PCM needs to know what exactly is happening in order to arrange proper gearshifts. Being slightly wrong (due to such as misfires) can easily result in shafts at the wrong speed and a thump.

Even where you don't feel/get a thump you can get trans fault codes.

The situation is even worse when the PCM does not also control the trans (as here) since then there are network (CAN) messages to co-ordinate PCM torque with the trans (ZF's TCM) expectations/needs.

So, the connection is either that the PCM does trans control as well (earlier cars) or the CAN bus.

 

Gosh, look at that poor saps fingers and thumb, yuk! Oh hey that's my hand!

 

well my mind is overwhelmed with all this info.. i have appointement thursday to get the transmission drain and filled and a new filter. not a flush, just a drain and fill.
then i will concentrate on the p0171 code.. we put on a new fuel filter, the old one was alittle dirty. tonight we drove it to supper about 10 mikes from the house, and it made the noise again.. but didn't on th e way home. sounds like its coming from farther back towards the fuel tank. could it be the fuel pump? is it in the tank? going to look on here for fuel pump issues... thanks everyone for your input.

 

Wow, thanks, that was quite the reply. Obviously I was thinking the PCM was smarter than it really is.

 

Vicki, the filter is part of the transmission pan. A word of advise that YOU SHOULD HEED. Change the electrical sleeve o-ring while the transmission pan/filter is off, being replaced. The o-ring is simple and cheap to replace WHILE the transmission pan/filter is removed. If I were you, I would ask to see the pan/filter AND o-ring, even take a picture of them and post back to this thread!

Good thing that you replaced fuel filter, but I believe that would cause a P0174 code as well. Get the ATF fluid, pan/filter and o-ring sleeve replaced. Focus on the P0171 code. I believe you will find your answers there to your issues.

Again here's the water. What you decide to do with is up to you.

 

Don't be too alarmed. These cars are not really any more complex than others of the same era.

Remember, that P0171 code is one of the most common you might see. Its's not a "scrap the car" indicator or anything extreme like that. It's the equivalent of getting the sniffles, as opposed to having a heart attack while falling into an industrial meat grinder. Any competent shop should be able to diagnose and correct the fault. It doesn't have to be a Jaguar specialist.

For the transmission, ask the shop to measure the quantity drained. That should give a good indication if the fluid was low, since there's no dipstick to check.

Another possibility for the clunk is a worn rubber bushing in the rear suspension. That might be worth investigating.

Keep us posted. As a new member, don't be a "Whine & Go" type of person, never to be heard from again. We've got way too many of those...

 

WELL, WELL, took the car to the local ford dealership today to get the atf fluid drained and a new filter and new fluid, BUT, they coudn't do it because they didn't have the right fluid or the filter. duh, what were they thinking 4 days ago when i called and ask if they could do it and i made the appointment.so we theft and went to another shop. that works on imports. he said i should wait till the car has about 90000 on it then come back. Soooooooooo i think i will see about the po171 code for now. the check engine light went off today by its self. why would it do that.

 

Copied (and slightly modified) from another recent thread:

"That's easy. It's all part of the logic of when to turn the light on and off, based on the severity of the faults detected.

The most severe condition, a fault bad enough to melt down the catalytic converters, will turn on the light immediately, and cause it to flash to get your attention. This means pull over and shut off the engine. If the suspect cylinders can be identified, generally those injectors will be shut off to limit unburnt fuel reaching the cats.

Medium level faults turn on the light right away, or at least by the end of that drive cycle.

Low level faults MIGHT not be valid. To prevent a nuisance indication, the light doesn't come on until certain conditions are met. Generally this means the same fault must be seen on successive drive cycles. The faults are stored as pending, but the light only comes on once all criteria are met. You can travel hundreds of miles on one drive cycle with a pending code but no light. If the fault is still active, the light only comes on with the next drive cycle, usually after a certain amount of time or distance."

The light also turns off if the fault is no longer active. Usually the computer must see several successive drive cycles without the fault before the light is commanded off. Sounds like your lean condition is right on the edge of setting the P0171 code. One day it was over the line enough to set the code. The next day it wasn't. Don't be alarmed if the light comes back. That is common with a fault condition close to the threshold.

 

I believe that the local Ford Dealer did not have the pan/filter, but as mentioned on this forum several, SEVERAL times, Ford Mercon SP is a compatible alternative to the liquid gold Lifeguard6. Yes, the mechanic is correct at the 90,000 mile mark, but several of us on here have drained, filter and electric o-ring sleeve well before 90,000. After the pan/filter change, I personally have drained and filled 5 other forum members S Types and XK8s within a few thousand miles after pan change.

Call me crazy, I just Googled transmission shops near Galena, Mo.. Guess what, there are several that look competent, just saying. Looks like there is an Aamaco not to far off either.

Again, I offer the water, what you choose do with it if you are thirsty...........