P1681 CADILLAC Control Module Not Programmed

Possible causes
– Fualty ECM
– Wrong ECM for vehicle
– Service program error
When is the code detected?
Engine Control Module (ECM) program does not recognize the vehicles id, or the id is missing in the ECM.
Symptoms
– Engine Light ON (or Service Engine Soon Warning Light)
P1681 CADILLAC Description
This diagnostic trouble code (DTC) indicates a programming error within the control module.