Pcm or clock spring or both?
 

hello,
im looking for some advice regarding my 2001 xj. i recently got it back from the shop after getting some rear brake work done. while i had it in there i asked if the mechanic to see what codes where coming up because the CEL is on and the airbag light comes on intermittently.

the mechanic came back with po123: idle position sensor high voltage, po505: idle air control motor circuit shorted, P0130: upstream O2 sensor heater relay circuit fault, PO136: downstream 02 sensor heater relay circuit fault, P1491: radiator fan relay circuit open or short, P1596 speed control switch always high.

His diagnosis is that i need a new pcm. He didn't mention the airbag light. Is it possible a bad clock spring could be causing all or some of this? and does is sound likely that i need a new pcm? any advice would be greatly appreciated. the car is running fine despite a slight hesitation when first started on a cold engine and misfiring in between 65-70 mph causing a buck. other than that has been very reliable. Again thanks for any help you can provide.