code p1660 Service engine soon light on 1996 Cadillac DeVille

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On my 96 cadillac deville the service engine light is on and the people at Autozone did a test on it and it came up p1660 which i know is about the cooling fan control circuit fault---ECM detected an improper voltage level on the output driver module for the cooling fan driver circuit.
Is this an easy fix???
(1) Answer
This may not be such an easy fix on your 1996 Cadillac DeVille. You will need to find the cause of the improper voltage level on the fan control relay circuit. There a multiple fan relays you will need to know which one is casing the problem and then diagnose the fault related to that specific relay. At minimum I would think you will need a wiring diagram and the diagnostic trouble tree for the code p1660.