Bad grounds burn out crank sensor?

My 92 Bonneville has an intermittent start problem. It seems to be worse when the weather is cold outside. The engine cranks fine but gets no spark. The shop I've taken it to has said "the crank sensor is faulty" 4 times now and replaced it that many times in a little over a year. I subscribed to Alldata so I could look up the wiring diagrams and it seems the PCM has the grounds for that circuit inside it. Is it possible the ground is poor causing high resistance in the circuit which in turn burns out the crank sensor? The sensor is just a hall effect device so something has to be screwing it up further down the circuit. Ideas?

Check where the PCM reference ground originates. Look @ ICM terminal L
Have you checked the ICM ground IN terminal K & the mounting (backside) for corrosion?

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