On my 2004 XK8 I just got an engine code 1229. I think this is related to throttle body or tps. The restricted performance cleared after a restart. I know earlier MY cars commonly had TB or TPS related issues, but honestly in all of my reading on this forum I never have seen or heard of issues on the later years, and 1229 seems rare. Any thoughts? BTW, this seems related to my surging problem, which I thought was resolved but now is back. This happened while on the highway, steady seed, constant surge.

 

It's probably not the battery but do check it's at least 12.4V after a long stand (like overnight) without the engine running.

 

Thanks for the thought, yet battery was load tested just to be positive it wasn't the issue.

 

After continuing to drive the car, I got increasingly good at making the surging happen. In fact I would drive it and purposely try to make it surge for as long as I could keep it going like that to see if it would produce a code, and or to monitor as much OBD live data as possible to see if there was a clue. Keeping the surging going for about 50 seconds is how I got the code the first time. I now have little doubt there is a connection between the surging mentioned in another post https://www.jaguarforums.com/forum/x...ighway-118098/ and the p1229 code. One time I received a p1226 code, but i have had the 1229 code now about 10 times. I also was getting good at driving the car and avoiding getting a code and fail safe mode, by not keeping the throttle steady or not at just a slight pressure, this avoided the surging and the code, allowing me to drive it as needed, I just stepped on the gas, then off, then on, then off, etc. Progressively the problem became more prevelant and frequent, and now I can't drive the car more than a minute or so without fail safe and the code. I clear it, shut off the car, restart, ok again. Sometimes now even at idle the idle will hunt up and down, which it never did before, and then will throw the code.

I have checked and rechecked all of the connectors on the throttle body. I cleaned them with electrical cleaner spray. I re-cleaned the throttle plate with TB cleaner and a tooth brush. Remember, this started out as a very very subtle and intermittent highway surg, and now this. Without any other options or ideas from the forum, I did what I think I had to, I ordered from SNGB a new throttle body, it should arrive here mid next week, I am thinking they said Wednesday July 2. It wasn't all that pricey, I think $330 or so. I suppose that with 100k miles any part can wear out, but I have not heard of any 2003 and newer TB's going bad...just seems strange. I will let you all know how it is after the replacement.

 

SteveJacks,

Is that a new throttle body, or a rebuilt throttle body. Either way, that's a good price...would you mind confirming for us that is what you paid? Several of us...including me...will be in the market for a throttle body soon.



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I actually don't know if it is new or rebuilt. I am thinking new, as it is coming from the UK, but honestly I just don't know. I did verify that I paid $330. I would caution on getting your hopes up on the price being low like that on the earlier models, as I suspect there is a supply and demand free market system driving up prices on the early models. As I said, I hadn't ever read a post for anyone with a 2003 MY or above needing to replace the TB, so maybe the warehouses just want to clear space?

 

I'm not sure about later cars, but there were problems with early XK8s which involved the replacement of some throttle bodies under warranty. My understanding is that dealers were given a stock of these by Jaguar, and some are now being "sold off" at a substantial discount.
If you are looking for a C2A 1470 throttle body, you can get a C2A 1470EK (note the suffix) for as little as £250.00 UK - $300.00 (ish) US. Exactly the same kit, but the suffix indicates a Jaguar warranty replacement item. I suspect that once they are gone, they are gone, so if you think you might need one in the foreseeable future, this could be a good time to buy !
I got one a few months ago and will be installing it when I do a full hose change later this year.

 

https://www.jaguarforums.com/forum/a...eplacement-pdf

Well this is interesting, I have never seen this TSB before. While it is closed and expired, and isn't the same code I was getting, I wonder why it was specifically issued to the Middle East, it gets hot here in Florida too. And the VIN range applies to my car as well. Just thought I would share this as I hadn't seen it, nor anything regarding TB's for later model year XK8's.

 

I missed my car, way more than I ever thought I would. As mentioned, i had been intermittently getting this p1229 code and the car would be undrivable until clearing and restarting. Generally I could drive it and manipulate the throttle to avoid the error and keep going. But (to my good fortune really because intermittent problems are tough to troubleshoot) the intermittentcy became chronic and constant to the point that it would not run normally at all. I ordered from SNG Barratt a new throttle body for only $330 (it appears to be brand new, not rebuilt), and gasket. It took a week to arrive at SNG, then another 5 days of ground shipping to me and arrived today (I should have asked for overnight delivery from New Hampshire to me). Anyhow, installed today and all problems are gone, runs smooth, I am so happy to have Jaxson back up and running.

I took the old TB apart. The gear drive for the throttle plate was in seemingly perfect condition, and pulled the throttle plate motor out, saw nothing apparent there either. The motor is self contained. The throttle plate didn't seem to be sticking at all. All I can think is that based on the code, the stepper motor just may have gone bad.

Even though I replaced more parts than ultimately were needed (yes, a little shot-gunning troubleshooting was done) by replacing plugs and injectors, I am happy with that, now I know THEY are new, and overall, I still came out ahead on the money game VS bringing it to the dealership.

 

Glad you seem to have the problem fixed now.

I've got a throttle body on the way, as well...part number C2A 1470EK, referenced in a earlier post to this thread, is indeed available in the $350 range. I ordered one from Gaudin yesterday, will have it next week.

By the way, the guy at Gaudin told me that the "E" in C2A 1470EK specifies that it is a remanufactured unit...all wear parts replaced and some "tuning" of the TPS and stepper motor done by Jaguar before shipment.


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This isn't my imagination and I CAN understand how it could be, from the technical perspective, yet, I didn't expect this. I am amazed at how different the car drives, particularly around town and at slower speeds/stop and go. Since buying the car with 62k miles, it has always had a touchy gas pedal, making it difficult for smooth starts, and has always had a slight clunk downshifting to 1st to a stop. It was driveline clunk, like backlash in the differential. This isn't the famous "lurch", just a subtle thing. Since the new TB, upon coast to a stop, I notice the tach suddenly drop from around 1000 rpm to 550, and it is so different from before, I momentarily think it stalled, but it doesn't, it is like the torque converter wasn't disengaging before the TB replacement, yet now it is, and it just freewheel coasts. That is how I would describe it, not saying that is what is happening. Also, starts are smoother, less sudden. It was as if I was pressing hard on the pedal before, even though I was trying to smoothly and slowly press the gas pedal...this isn't so dramatic as it sounds, but a subtle difference now, just smoother. Finally, their often (usually) was a slight hesitation upon starting with light throttle...now that is gone, and it is like I almost catch myself looking for it now.

Anyhow, just thought I would share this with you all. The car is transformed, even though these are subtle differences, they make a big difference in how the car drives. I have to think that there has always been so,etching amiss with the original TB.