My Trane XL1200 continually shuts down with an error code that says "Replace Control." I jumpered around the thermostat to eliminate that and problem prevails. Does Trane mean replace the control board? I can't find a CNT1669 anywhere if this is the problem.

It could be one of many controls in the unit.

Any suggestions to find out which one?
Thanks.

Use the wiring diagram and track them down with a meter.

Thank you HVAC1000. I was thinking of a shot gun approach, but the CNT1669 main control board might be really expensive. So far I've not been able to find the board anywhere, or at least anywhere that'll sell it to me.