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Home >> GMC >> 1991 >> Value Van 7.4 N >> Repair and Diagnosis >> External Pages >> Different car >> Section 43 (Engine Controls - Tests W/Codes - 8.0L) >> No-Start Tests >> Test NS-7A - Inspecting Idle Air Control Motor Operation

Test NS-7A - Inspecting Idle Air Control Motor Operation

WARNING: This page is about a different car, the 1995 Dodge Pickup and 1995 Dodge Cab & Chassis. However, it is still accessible from the selected car via links, so may be relevant.
NOTE: For circuit and connector terminal identification, see CONNECTOR IDENTIFICATION  . For wiring diagrams, see WIRING DIAGRAMS  section at the end of this article.
  1. Hold throttle 1/4 of the way down. Attempt to start engine. If engine does not start and remain running, go to TEST NS-8A. If engine starts and remains running, release throttle. Turn ignition off. Go to next step.
  2. Disconnect Idle Air Control (IAC) motor connector. Turn ignition on. Using scan tool, actuate IAC motor. Using scan tool in voltmeter mode, check voltage on IAC motor connector, driver No. 3 circuit (Gray/Red wire). If voltage stays less than one volt, go to TEST NS-7B.
  3. If voltage does not stay less than one volt, check voltage on IAC motor connector, driver No. 1 circuit (Brown/White wire). If voltage stays less than one volt, go to TEST NS-7C.
  4. If voltage does not stay less than one volt, check voltage on IAC motor connector, driver No. 4 circuit (Violet/Black wire). If voltage stays less than one volt, go to TEST NS-7D.
  5. If voltage does not stay less than one volt, check voltage on IAC motor connector, driver No. 2 circuit (Yellow/Black wire). If voltage stays less than one volt, go to TEST NS-7E.
  6. If voltage does not stay less than one volt, turn ignition off. Remove IAC motor from throttle body. Reconnect IAC motor connector. Turn ignition on. Using scan tool, actuate IAC motor. If IAC motor pintle moves in and out, go to TEST NS-8A. If IAC motor pintle does not move in and out, replace IAC motor. Perform TEST VER-1.