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Diagnostic Aids

Perform this test only when directed here. This test is intended to diagnose the following:

CIRCUIT PIN IDENTIFICATION

Circuit PCM Pin No. Wire Color
IDL 26 Brown/Yellow
IGN 38 Blue/Yellow
TCM TCM 17A Red/Yellow

  1. DTC 0510: Check Idle Switch Continuity

    Turn ignition off. Disconnect idle switch harness connector. Ensure throttle is closed. Measure resistance between IDL Brown/Yellow wire and IGN Blue/Yellow wire terminals on idle switch. See CIRCUIT PIN IDENTIFICATION  table. Also see Fig 1. If resistance is less than 5 ohms, go to next step. If resistance is greater than 5 ohms, replace idle switch. Restore electrical connections and repeat QUICK TEST .
    Fig 1: Identifying Idle Switch Harness Connector Terminals
    G99J02329Courtesy of FORD MOTOR CO.
  2. Check IDL Circuit For Open

    Turn ignition off. Disconnect PCM. Measure resistance of IDL circuit (Brown/Yellow wire) between idle switch harness connector and PCM connector terminal No. 26. If resistance is less than 5 ohms, go to next step. If resistance is greater than 5 ohms, repair open Brown/Yellow wire. Restore electrical connections and repeat QUICK TEST .
  3. Check IDL Circuit For Short To Ground

    Turn ignition off. Disconnect PCM and idle switch connectors. Measure resistance of IDL circuit (Brown/Yellow wire) between PCM connector terminal No. 26 and negative battery terminal. If resistance is 10 k/ohms, go to next step. If resistance measurement is less than 10 k/ohms, repair Brown/Yellow wire for short to ground. Restore electrical connections and repeat QUICK TEST .
  4. Check IDL Circuit For Short To Power

    Turn ignition off. Disconnect PCM and idle switch connectors. Measure resistance between IDL circuit (Brown/Yellow wire) and VPWR (Black/White wire) circuit at PCM harness connector. If resistance is greater than 10 k/ohms, replace PCM. If resistance is less than 10 k/ohms, repair short to power in Brown/Yellow wire. Restore electrical connections and repeat QUICK TEST .