Art, I think you're right.
In searching the web I located your post to the LRX BB about a year ago and one other (Motorcars LTD forum). I posted the question there and got this response:
"From what I gathered from the manufacturer, this code is an internal code caused by the tester, usually due to wrong connecting/reset."
Weird, maybe it's somehow tied to the other code.
Anyway, thanks for the reply.
Arthur M Vigil
Former owner of:
'95 RRC - 3.9V8 Rimmer Supercharged!
'72 Series III 88" NADA Turner 2.25 petrol (Lovely Rita)
'95 RRC Brooklands/TWR Edition 3.9V8
'97 D90SW NAS #2426 - 3.9V8 Rimmer Supercharged!
'95 D90ST NAS#2620 - Original owner