Edited on 2013-11-07 21:58:06
Vienna, VA
Attn Stephen Tetry-- dealer said code is p0773
When going slow, sometimes with I get harsh sudden shifting gear 1-2. Sometimes I get the error message "gear box fault" The error goes away after turning off the car. Fault codes are p0780, 0781, 0782, 0773.
Dealer said to replace transmission. I asked them to check battery and elec connections and they found low charge. They charged battery (no bad cells) and reflashed TCM and PCM software. They did not say what trans fluid level is.
I need to know what to check and am not convinced I need a $7,300 rebuilt transmission. I have been test driving for 2 days. No dash warnings. Still harsh shifting at low speeds if I am not gentle with the throttle when starting out at low speeds. DonÔÇÖt know if there are still error codes. I heard that the battery should be disconnected for 30m min. to reset them.
BTW the manufacturer of the trans, zf, said they now recommend replacing (not flushing) the trans fluid every 60k, only using ZF Lifeguard 6 fluid and checking level after reaching the spec temperature while engine running = no excess fluid should flow out.

Submitted by deheagy@yahoo.com on Wed, 07/30/2014 - 09:25

Problem solved. After dealer replaced battery and software update and reflash, error code did not return and shifting normal.
I think they followed Update 6HP26 TCM Adaptive Reset Trans in Jaguar Technical instruction.

Also, called transmission manufacturer ZF now recommends a 60k mile ATF/filter change for the 5HP24 transmission

Submitted by jp2531@comcast.net on Tue, 12/10/2013 - 20:47

You have an adaptive transmission. The type of driving can effect the way your car shifts. We have been told it is possible with extended city driving the car may not shift into 6th gear.

Why are you having the re-configure your ECM? It should have no effect on your transmission. When they did your reconfiguration did they give you instructions on how to drive the car for the fist few hundred miles such as not using sport mode?

Please keep us updated on your shift quality issue.

Submitted by deheagy@yahoo.com on Thu, 12/05/2013 - 23:01

Edited on 2013-12-05 23:04:01
Edited on 2013-12-05 23:02:33
Final (I hope) diagnosis for the 03 XK8 gearbox fault and harsh gear 1-2 shifting:

10/30/13 shop visit: Original dealer diagnosis- replace transmission with rebuild- $7,300.

Based on comments from this forum and http://www.jaguarforums.com/forum/xk8-xkr-17/xk8-2003-gearbox-fault-tran...
I asked for battery check and recharge.

Dealer tested battery- low charge, cells ok. Recharged and warning went away.
Reflashed TCM and PCM

Warning gone, but harsh 1-2 shift
Cost $130

12/5/13 shop visit: dealer says battery would not hold charge. New battery. (Said maybe tester used before was faulty.

Re-configured existing ECM
Check fluid level and color- OK
Says no codes or warning.
Shifting ok.
Do NOT need trans rebuild.
Pick up car tomorrow. Cost including battery $230.

John A- regarding "What type of driving do you do? I would suggest you try driving the car very aggressively for app 50 miles & see if it shifts any better." I do not drive aggressively since usually in town and short interstate trips. It has had some aggressive sessions during FATT class at Summit Pt. Why would driving style affect shifting behavior?

Submitted by jp2531@comcast.net on Tue, 12/03/2013 - 21:03

My question was directed to Steve. I was wondering what his special procedure was. In your post you mention reflashing the TCM. Did they reprogram the computer? The Jaguar reflash using IDS has the proper ZF software. You have an adaptive transmission in your car. What type of driving do you do? I would suggest you try driving the car very aggressively for app 50 miles & see if it shifts any better. You may very well need a transmission as it is not unheard of. You may want to ask your dealer if they think a coded access will help with your car. If they do make sure you drive it the way they say for 500 miles.

Submitted by deheagy@yahoo.com on Sun, 12/01/2013 - 20:29

John, I am asking the dealer to review the diagnostics and work done, and address these items:
1. Recommendation to replace transmission with rebuild $7,282.50 before the battery voltage was checked and corrected, and electrical connections checked. (after battery charged the GEARBOX FAULT warning has not reappeared.
2. Not disconnecting battery for 30 min to erase ecu's memory
3. Not checking fluid level at recommended temperature.
4. How the TCM and PCM software reflash steps they used compare the the manufacturer's (ZF) procedures.
5. If the ZF procedure and battery disconnect solve the harsh 1-2 shifting from a slow speed.

Submitted by stevejag@sbcgl… on Mon, 11/18/2013 - 12:50

David,

The shifter has 4 manual positions on the left side [manual side] of the J-Gate. Those represent the highest gear the trans will be allowed to use. If you start off in "4", the trans will upshift normally but stop at 4th regardless of your speed. The "D" position will allow use of all six gears. At highway speed, you can confirm you have reached 6th gear by sliding the shifter to "5" and watching the tach. If the RPM rises, you confirm the downshift from 6th to 5th because of it. If no RPM rise, you were in 5th instead.

Since you no longer seem to have the gearbox fault, I have a procedure I would suggest you ask the dealer to try. Keep in mind it may take some sweet-talking to get them to follow it. They don't always like being "told" how to do their job. It will cost some money, and may duplicate something they have already done, somewhat; but it needs to be done in the correct order. Given your situation as you have related it, this is what I would do if the car were mine, or if you were my client, before I would consider replacing the trans.

As I said, it may cost you four or five hundred bucks, depending on the local labor rate, [it will take three hours or so to accomplish] so you will have to weigh it carefully. It is a roll of the dice in a sense, but you could end up with a car that drives like new, also. It's not an easy call, but if you want to consider it, give me an email address and I will send you the procedure.

Cheers,

Submitted by deheagy@yahoo.com on Sun, 11/10/2013 - 23:02

S Petry, The shifts are at about 15-20 mpg, 30 mph, and 50 mph. No gears are skipped. I would have to go much faster than 50 to get another shift.
Rarely, when I am in 2nd gear (I think), and I am almost stopped, and I do not gently push on the accelerator, there is a harsh up shift. It does not happen all the time.

The "gearbox fault" warning has not reappeared after getting the car back from the dealer. They said the fluid is not low. They do not check the temperature and assume that after it is driven the fluid is warm enough to check the level. They also said the battery was low, and they recharged it after I asked them to charge it and check the electrical connections on the trans.

If the shift pattern on the J console shows 5 positions, does that mean I do not have model ZF 6HP26

Submitted by deheagy@yahoo.com on Sun, 11/10/2013 - 19:14

S Petry, The shifts are at about 15-20 mpg, 30 mph, and 50 mph. No gears are skipped. I would have to go much faster than 50 to get another shift.
Rarely, when I am in 2nd gear (I think), and I am almost stopped, and I do not gently push on the accelerator, there is a harsh up shift. It does not happen all the time.

The "gearbox fault" warning has not reappeared after getting the car back from the dealer. They said the fluid is not low. They do not check the temperature and assume that after it is driven the fluid is warm enough to check the level. They also said the battery was low, and they recharged it after I asked them to charge it and check the electrical connections on the trans.

If the shift pattern on the J console shows 5 positions, does that mean I do not have model ZF 6HP26

Submitted by stevejag@sbcgl… on Fri, 11/08/2013 - 11:44

David,

I need you to do another thing. Take a couple of days and as you drive, when you leave a stop, carefully watch your tach and count the shifts. That is you'll start in 1st of course, but count the gears as you accelerate. Watching the tach will help because sometimes the shifts are soft, but you will be able to confirm the shift when you see the tach drop.

What we are looking for is to be sure you consistently verify EACH gear, [total of six] and that they are spaced normally. We don't want to see any two shifts spaced really close together, just boom. boom. We don't want you to noticeably skip a gear either. Keep in mind you have a lock-up torque converter, also. It will sort of seem like a shift, but will be a smaller RPM drop.

I'm not convinced a trans replacement should be the immediate choice here either, but it may come to that.

Cheers,

Submitted by stevejag@sbcgl… on Thu, 11/07/2013 - 20:03

David,

I have a full plate tonight, but clarify for me the last code you listed. Is that really P0773, or was that a typo and should be P0783?? I'll review this when I can and comment later, hopefully tomorrow.

George, you ol' dog........ Six people, HA! I caught that! :-)

Cheers,

Submitted by SE98-32482CJ on Thu, 11/07/2013 - 19:43

David I am glad you got to post. Evidently when we spoke the forums were having an issue--I guess too much demand but I hope at least 6 people get through. You have asked the right person but his name is Steve Petry--