I have a 99XK8 which is showing among other codes a P1000. From what I am reading on this forum and others that this code only shows up after any codes have been cleared? My issue is this I picked up my car from being serviced and within 10 miles of driving the check engine light came on and after another few minutes it went into restricted performance. I shut it down, waited and restarted. Check engine light was on but no RP. The garage said they knew nothing. Would they have had to clear the codes in order to get a P1000 code? Hope this makes sense.
Ken

 

They either cleared the codes or interrupted power to the ECU. If they disconnected the power cables from the battery, that would set P1000 also. What was the car in there for?