T1 DIAGNOSTIC TROUBLE CODE (DTC) P1663 — FDCS CIRCUIT FAILURE
DTC 1663 indicated that the PCM has detected a failure on the FDCS line.
Possible causes:
Open/short in FDCS circuit
Non-powered IDM
IDM
PCM
Check for other codes.
Key on, engine off.
Perform KOEO On-Demand Self Test and retrieve Continuous DTCs


If you pull the chip , make sure the key is in your pocket...