Hello
I have a 2004 STR with 142,000Km on it.I had the transmission pan,filter and fluid all changed by a transmission shop along with the connector sleeve.I used the kit from California Transmissions with the ZF fluid.The transmission moves smartly when it is put into gear now.However,the previous problem of the transmission surging between 40-60km/hr still persists.In addition,the transmission seems to take longer before it shifts into top gear on the highway.What is odd is that if push the sport off then on again the transmission quickly changes to the higher gear.

I have heard that the transmission can be reprogamed?

Any thoughts on this?
Thanks.Fitz

 

You may have a failing TC (see below) but yes reflashing is possible and fairly cheap at a dealer. Fuller details on here if you're inclined to read more.

 

My 03 STR recently had the same symptoms. As jagv8 suggests: worn torque converter (TC) or trans. A rebuild of both along with a TCM reflash did the trick. First go for a TCM reflash and see what pans out. The surging is more indicative of a worn TC.

 

Another vote here for a failing TQ clutch. Seems the 2003-2004 STR's see this problem more but it could be those cars just have more miles on them.

Have you read the other threads about surging or small RPM changes? It's pretty well known and there are at least 2 TSB's from Jaguar on it.

It is recommended that the TCM be reflashed when the transmission is serviced. This requires a dealer.

Did you get the TCM reflashed when the fluid was changed? If not I would do that before replacing the TQ. Hopefully people that have had the TQ replaced can direct you to the best price. But it is unlikely the reflash will help with the surging. You did not mention any lurching problems and the reflash helps a lot more with that problem.

It will cost a good bit as the transmission must be removed to change the TQ.

One last thing be careful about who you use to change the TQ! The drive shaft is balanced using the nuts and washers that connect the guibo (Rubber Biscuit) to the transmission. So the attaching hardware MUST be reinstalled in exactly the same place or you could get a bad drive shaft vibration after the change.
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The surging sounds like symptoms of a failing torque converter.

I'm not 100% sure on this, but my observations have been, when in sport mode, the car prefers to stay in 5th, and will avoid shifting into overdrive, 6th. (might not shift into OD at all in sport?) This may address the one issue you described, but again, not certain if this is an absolute thing, just my experience.

 

Thank you everyone.I will try a reflash first and see if it helps.
Fitz

 

Is there a certain code they should flash the TCM to? I'm just wondering, I have mine flashed a couple of weeks ago and I called the dealer today to ask what version they flashed it to and they have no idea, said I needed to bring the car back in for a service appointment to find out. Does this sound correct? Shouldn't they document what they did? When I took it to them, I asked them to put the latest release on. Any thoughts?

Thank you,

 

They probably used IDS/SDD. It flashes the latest version, going online to get it if need be.

You can read the TCM version (calibration) using a suitable OBD tool if you want to but may be more trouble than it's worth.

 

Do you have the Jaguar service receipt? When I got mine done it listed the TSB number and the calibration version they installed.
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Well,the reflash reprogram seems to have cleared up the surging.Jag tech thinks there is a flare occurring between 3-4 like the transmission is still holding 3rd gear while it changes into fourth.Reflash seems to be helping with the transmission going into top gear easier.When the trans is in regular mode it seems to shift normally into top gear or when I click sport mode off it shifts instantaneously into 6th gear.I wonder if this is electrical?

Jag tech said I needed to drive the car more since it was very icy and raining when he reflashed and did road test.

Jag tech says if problem persists he wants to rebuild transmission( at 142,000km now).

Fitz

 

edit: woops, somehow posted this reply in entirely the wrong thread.

 

FJG - What do you mean "electrical"? Everything is software, always, as regards when to shift and where to. Once the parts are set in motion at some point they're mechanical, of course. But what hits and how fast/hard is software controlling it "electrically".

However, there are likely to be safety interlocks / over pressure / etc things to prevent very bad outcomes.

 

Hi Jag V8
The reflash seems to be helping and the car seems to be shifting fine in normal mode.The surging seems to have stopped.I am wondering if there is an electrical problem when the car shifts into top gear as soon as i hit go from sport back to normal mode.I normally keep the car in sport mode.

 

I suspect only a trans specialist would really know but is it worth paying to find out?