Code won't clear
 

The car is a '93 Federal 300CE with 195K
In my continued efforts to solve my "limp home" problem, I tried swapping CCU's. The new (used) one worked perfectly but limp home is still with me. Curious about any new codes I checked mine again. This one showed up:

#42, Pin 8, "CAN communication from ASR, EA/CC/ISC module or diagnostic module (OBD II) faulty"

I also get #9, Pin 14, "Left rear axle speed sensor from ABS/ASR control module or in 124 chassis Hall Effect speed sensor." ( I had recently changed the wheel sensors and the Hall effect sensor behind the speedometer (with used components)

All of the codes were read and cleared with the exception of #42 above. Repeated attempts would not clear this code.

Does anyone know if this is normal for this code and whether code 9 on the other pin may be the cause of #42?
Thanks in advance,
Anziani
'93 300CE
'95 E420