Car gave an E30

1993 CADILLAC DEVILLE
100,000 MILES • 4.9L • V8
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DEVILLE MAN 93
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I have the car listed above Sedan, and the only code I have right now is a E30. I know it means ISC RPM out of range, but responses vary, saying that I need to replace the Idle speed control motor or the Idle air control valve. What should be my first step?

(Please note that my dash doesn't have an RPM counter, only MPH)
Jan 29, 2020 at 3:52 PM
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KASEKENNY
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I attached the flow test that we need to follow to determine if it leads us to another issue or if the ISC Motor, PCM, or something else needs to be replaced.

Unfortunately, we could guess but without following this, it would be just a guess.

Let me know if you have questions but again, the best thing to do is run through this until we reach a different path then we can go down that road.
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Jan 29, 2020 at 5:56 PM