Ford Mustang (1999-2004) Service Manual: Symptom Chart

NOTE: New speed control diagnostic software is available in Version 12 or higher for the diagnostic tool. When using this software, it is necessary to use Next Generation Speed Control Adapter 007- 00586 with the diagnostic tool.

NOTE: Refer to the Wiring Diagrams for connector numbers stated in the Pinpoint Test.

Symptom Chart

Condition Possible Sources Action
  • The speed control is inoperative
  • Central junction box (CJB) fuse 17 (15A), 33 (15A).
  • Battery junction box (BJB) fuse HORN (20A).
  • Circuitry.
  • Deactivator switch.
  • Clutch pedal position (CPP) switch.
  • Speed control actuator switch.
  • Speed control servo.
  • Powertrain control module (PCM).
  • Go To Pinpoint Test A .
  • The set speed fluctuates
  • Circuitry.
  • Speed control servo.
  • Powertrain control module (PCM).
  • Engine.
  • Go To Pinpoint Test B .
  • REFER to the Powertrain Control/Emissions Diagnosis (PC/ED) manual.
  • The speed control does not disengage when the brakes are applied
  • Central junction box (CJB) fuse 33 (15A).
  • Circuitry.
  • Brake pedal position (BPP) switch.
  • Speed control servo.
  • Go To Pinpoint Test C .
  • The speed control does not disengage when the clutch is applied
  • Cluch pedal position (CPP) switch.
  • Speed control servo.
  • Go To Pinpoint Test D .
  • The speed control switch is inoperative- COAST
  • Speed control actuator switch.
  • Speed control servo.
  • Go To Pinpoint Test E .
  • The speed control switch is inoperative- SET/ACCEL
  • Speed control actuator switch.
  • Speed control servo.
  • Go To Pinpoint Test F .
  • The speed control switch is inoperative- RESUME
  • Speed control actuator switch.
  • Speed control servo.
  • Go To Pinpoint Test G .
  • The speed control switch is inoperative-OFF
  • Speed control actuator switch.
  • Speed control servo.
  • Go To Pinpoint Test H .
    Inspection and Verification
    NOTE: If any concerns are noted with the speedometer, stoplamps, or horn, address those concerns by referring to their associated sections before continuing speed control diagnosis. 1. Verify the cu ...

    Pinpoint Tests
    PINPOINT TEST A: THE SPEED CONTROL IS INOPERATIVE Test Step Result / Action to Take A1 CHECK THE SPEED CONTROL SERVO VOLTAGE AND GROUND YesGO to A3 . No GO to A2 . Ke ...

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