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Home >> Cadillac >> 1991 >> DeVille Touring >> Repair and Diagnosis >> Engine Performance >> System >> Engine Controls - Tests W/Codes >> Pcm Flow Charts Codes E12 To E99 >> Pcm Code E91, Park/Neutral Switch Problem >> Note On Intermittents For Flow Chart 1
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Note On Intermittents For Flow Chart 1

The PCM data displays P.2.2 and P.2.3 indicating status of each of the 4 circuits. A pull-up resistor produces a battery voltage signal at the PCM terminal when circuit is open and no signal when circuit is to ground. See table in Code E91 electrical schematic.