I have been collecting Failsafe mode codes on my '01 XKR. After spending many k$'s on many replacement parts I still have an intermittent issue that can betemporarily resolvedby cycling the car on/off several times. As soon as the Failsafe mode clears (and assoc. ABS & ASC warnings) it performs extremely well for another week or two. The latest fault codes are : B1229 CONTACT DIAGNOS.CO.UK FOR DESCRIPTION & P1229 TRHOTTLE MOTOR CONTROL CIRCUIT MALFUNCTION. My local shop has already replaced the throttle relay but this hasn't really resolved much. The errors generally occur when it is hot outside (most of the time here in TX) and after I have driven it 2-3 miles. Not sure if this is relevant or not.
I really enjoy the car a lot more when I am driving it and not when the shop guys are test driving it!
dugem260

 

Go to my web page and select Throttle Body. Not sure but it may apply.

 

sounds like you need a throttle body .. there a few thousands.