My 99 convertible is going into limp mode showing Transmission fault on the message centre. Stored DTC is P1632 but I can only find a listing for this based upon 2003 MY. Anybody know the possible causes based upon 99 model year please?

 

This is what I found:

Aug. 1, 2000
Component: Vehicle speed control cables.
Bulletin Summary: Some vehicles may default to limp home mode because the throttle cable is improperly adjusted. The condition will be accompanied by diagnostic trouble code (dtc) p1121 and / pr p1632 being stored in the memory of the engine control mod
Vehicles covered in this TSB:
1999 Jaguar XJ, 1999 Jaguar XK8.

 

I've searched and can't find that TSB - would you have the number by any chance? Thanks in advance.

 

OK - I eventually found it - for the benefit of anybody else searching it's TSB310-05.
Adjusted the throttle cable as per the TSB, ran fine for 35 miles then back to limp mode. Pulled the codes again and this time got P1632 and P1122(TPS sensor 2) and noticed it seemed always to throw its hissy fit as I was coming to a stop so starting to suspect throttle body(or more precisely TPS) . I had a new spare TB that I bought 2 years ago for the right money - fitted it and so far all is well - car seems to change gear more smoothly as well(OK - could all be in the mind). Am I right in thinking no one has ever managed to source the Denso TPS or an equivalent? At the moment I have an interesting looking paperweight that it would be good to return to working order :0)

 

You might consider sending it off to be rebuilt? Handy to have a spare as you found out!
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Great sleuthing on your part, batroute. Keep us posted on whether the replacement throttle body permanently solves your issue. We've had no issues with our 2006 XK8 throttle body, but our 2005 S-Type throttle body had to be replaced while the car was still under the factory warranty back in May 2009. The slightest trace of moisture in the system plays unmitigated havoc with these Jaguar throttle bodies, much more so than any other vehicle I've owned in the past 40 years. In contrast, my 1999 Dodge Ram pickup's throttle body wouldn't even burp if I poured a quart of water straight down the pipe....

 

Yes - I thought of that but there seems to be mixed reports of rebuilds just lately - no one really seems to know how they are repairing the TPS, also if I can source a TPS it will be cheaper than a rebuild. There was some talk of using a S type TPS but can't seem to find out if anybody tried this out- there's a long thread on this started by Steve in France but the trail seems cold.

 

To date no further problems - car is running perfectly(that's jinxed it) - and interestingly the P0172 and P0175 have not occurred again since the new throttle body was fitted. A local indie told me that in his experience these cars can throw all sorts of rich and lean codes leading to RP messages when the throttle body is starting to fail. I've sent the old TB to ASI for a rebuild and bearing in mind the other reports of problems with them(ASI) I'll let you know how that goes.
I also spent 4 weeks trying to source just the TPS - found a manufacturer who would supply but minimum order was 2000units. From the digging I did the TPS is also used on Isuzu/Toyota/Mazda but couldn't trace exactly which model. I bet ASI have figured it out though :0)

 

OK - I received my original throttle body back from ASI within about seven days - good service. It looks like they are changing the innards on the TPS - the casing has been opened and then resealed - it's definitely my original TPS. They have presumably figured out which other TPS has the same tracks and are repairing the units with those parts. The good news is that I've just got around to refitting the TB and it was plug and play(after a hard reset) so I've had no problems with the ASI rebuild service .