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1999 ford ranger 3.0 engine Check engine light code 1504

auxillary idle speed control. What is the most likely part replacement require?

This code usually points to a short within the Idle Air Control motor. This can be a short to power or a short to ground. This code can also be caused from a short to and from the IAC motor, or form a bad ECU. But 99.99% of the time, it’s because of a defective IAC motor.

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