For quite some time, I've lurked around these forums trying to find insight on my issue. I've decided to take this a step further by creating an account in order to get more specific information leaning to my particular issue, since everybody's else is different in perspective. This is my 3rd 2005 Jaguar S type R and like I listed in my forums, I've had the pleasure of enjoying each one in a different color (silver being my favorite). Nonetheless, I bought the car around 63000 miles and enjoyed it up until the past month. This is the first time this problem has occurred with me. Now the specifics…

It started with the 'lurch' problem from 1st to 2nd & 2nd to 3rd. Also when rolling off a stop. I also noticed that while driving anywhere between 45-70 for a few minutes, the rpms will slight rev up a bit and drop down in a continuous fashion and you can feel the car very lightly speed up and slow down very lightly, respectively. Eventually, the transmission fault light turned on, causing it to be stuck in 3rd gear. After turning the car off and on, this light will disappear, car will drive normally. Eventually, this trick didn't work and it remained on. Nonetheless, I finally took it into the dealership to get the codes read.

P0730 - Incorrect gear ratio
P0736 - Reverse incorrect ratio
P0731 - Gear 1 incorrect ratio
P0732 - Gear 2 incorrect ratio
P0735 - Gear 5 incorrect ratio

Going into the dealership, I was hoping that all it would need was potentially a reflash (progamming the ECM & TCM) & calling it a day. Of course, the dealership had something otherwise. He said these codes indicate something mechanically wrong in the trans (broken drum or clutch). To be frank, I didn't buy it, I figured he'd rather sell me a rebuild trans ($4500) or new trans (10K or my kidney) instead of doing the reflash for a measly $250. The car currently has 69000 miles on her. I was hoping you guys can give me some insight. I was thinking I should go ahead and attempt the reflash? In addition, he stated the trans fluid was at good level. What do you guys think? Sorry for the long post but I wanted to be descriptive!

Mike

 

You can try the reflash but with the codes you have it does not look good.

With your experience I won't ask about the battery as you know how important it is to have a good one before trusting all the error codes.

Have you erased the codes to see what comes back?

He is hard to get to but Klaus is an expert on ZF transmissions.

The CTSC - ZF Parts
.
.
.

 

I took the batter into consideration. Took it to auto zone to get it checked out. It came good but needed recharging. I left it there to get recharged to 100. Popped it back in, and nothing has changed. In addition, the dealership resetted the trans light but told me that eventually it will come back and that same day a couple hours later it came right back.

 

Also looking at the list of codes he printed me out, there were a couple cases where battery voltage was low or out of range

 

There are several instances here on the forum where a new battery solved the reported transmission issue, including shutting off the fault lights and messages. I would try a new battery first....

The Adaptive Drive Cycle Reflash worked for my wife's ZF 6HP26 in her 2006 XK8 last July. The car was at about 68,000 miles at the time. Just prior to that, a good friend here on the forum (Rick) and I had done the pan/sleeve/fluid change for good measure using one of Klaus' kits....

I would do a reflash and a ZF drain-and-fill before even considering any major surgery on the ZF. It's amazing what the dealerships do not know (or DO know but opt not to tell their customers) regarding sorting the issues on these ZF units....

 

All of the above could be your problem.

Here is another thought. I too have encountered the fault light and the incorrect ratio code. Mine happens after 2 hours of continuous high speed highway driving (70-90 MPH)

Had the pan and oil changed, still happened on my next long drive.

I searched on here for "incorrect gear ratio" all forums. (have not seen it spoke about on the s type forum much)

A thread by H2Oboy came up, he has the same trans as my 06STR.

He had the same symptoms and went through many different trials and errors.

Turned out a specialty Trans shop rebuilt his ...twice... after not solving his problem they figured he needed a new valve body. I think they just put the original back in each time figuring that it was ok and that nothing goes wrong with them.

If you search his name and all his threads you should find it, Its a good read.

Turns out that there is now a known fault with these valve bodies.

His tranny got worse over time and he was forced into the repair. Mine only does it on the long hard drive and is fine around town daily.

Good luck.

 

Good point and another reason to call CTSC. They sell valve bodies much cheaper than anywhere else I have found.

If you are a good mechanic be aware that there are a number of solenoids that can be changed too. CTSC also carries these. Either the entire set of 6 or 7 (I forget the exact number) or the individual ones.
.
.
.

 

I'm going to go ahead and look into this. I had a mechanic specialized in transmissions & he said it could potentially be the valve body. Thankfully, my brother is a mechanic so I'm thinking I will have him tear up the transmission and see if he can find anything out of the ordinary. Thanks!

 

As Jon has stated, I would consider the possibility of changing out the battery and perhaps a transmission fluid change / reflash might help.


I would think these would be perhaps your cheapest & simplest options to try first and foremost.
At 63k if it hasn't had a fluid change its long verdue, sealed for life doesn't work.
I had my XJ fluid changed at 61k and made a fair dfference, much smoother throughout.


My sons X type around 8 years old had the battery changed today, still had the original in.


Just some food for thought

 

Good advice and when refilling don't just put back the qty that came out as it could very well be low now. Fill as per stickies.

 

Nothing against your brother but he won't see anything different when he removes the valve body or shift solenoids. It's kind of a black box and replacement of the solenoids and/or the valve body is really the only way to tell if that was the problem.

Not a great way to repair stuff but it is a bunch cheaper than a new transmission!
.
.
.

 

I see. He advised we start off by changing the pan, filter and fluid and see what happens from there. So I'm guessing thats what I'm going to do, once thats done I'll give an update. Im debating whether I should take the risk of replacing the battery with a new one. It runs around 160 new, so ill figure that out within the next few days if I want to replace it.

 

I should add that I had a couple cases where I had a restricted performance light come on and go away and there was a rare case in which the dash stated trunk open when it wasn't and because of it I was unable to open my trunk. I am mentioning this because I just read a thread where a few people are advising someone who has the restricted performance that its a sign of a bad battery. Could all these issues along with the transmission fault really be because of a failing battery? I mean I hope this is the case. In addition, when all these problems began occurring, my radio frequency stinks. Constant clutter in the frequency as if my satellite connection has significantly weakened.

 

Yes indeed, classic failing battery signs. In September 2012, the trunk on my wife's 2006 XK8 began randomly popping open of its own accord. I actually heard it happen a couple of times while walking past it. At first I believed that the key fob in my pocket had somehow pulled the trigger without me touching it. A new battery rectified this issue (and several other classic failing battery signs that were beginning to intermittently show up)....

 

Yes. You need to be suspicious when you have multiple faults because it just does not make sense that you will have multiple failures all at once. Just does not happen.

So that is a huge sign that something else is at work.

Over time we have seen the battery cause this and far more stuff. Just too cheap to not replace.

Compare the price of a new battery to what you will spend on a transmission?
.
.
.

 

Aint that the truth. I'm just going to pull the trigger and purchase the battery. I'll keep you guys updated.