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This is quoted from some Honda service information:
Got a vehicle in your shop with DTC P1676 (FPTDR signal line failure) or TCS DTC 31 (engine retardcommand [PFINH] signal)? A bad ignition switch (the electrical half) could be the culprit.NOTE: On the HDS, you’ll see TCS DTC 31 listed as TCS DTC 31-2.Inspect the ignition switch solder joints for any signs of overheating. If you notice the solder joints aremelted, replace the ignition switch.
If you also have a stalling issue replacing the electrical portion of the ignition switch should also take care of that.