Ford Mustang (1999-2004) Service Manual: 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 customer concern by operating the speed control system.

2. Visually inspect for obvious signs of mechanical and electrical damage.

Visual Inspection Chart

Mechanical Electrical
  • Deactivator switch
  • Speed control actuator cable not attached to throttle
  • Speed control actuator cable not fully seated to the engine bracket
  • Central junction box (CJB) Fuse:
  • 15 (15A)
  • 33 (15A)
  • 35 (15A)
  •  Battery junction box (BJB) fuse:
  • HORN (20A)
  • Wiring harness
  • Loose or corroded connections
  • Speed control actuator switches

3. If the fault is not visually evident, verify the symptom and GO to the Symptom chart.

    Principles of Operation
    The speed control system is designed to maintain vehicle speed above 48 km/h (30 mph). After the ON switch is depressed, depressing the SET/ACCEL switch will activate the speed control servo. To inc ...

    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- ...

    Other materials:

    Actuator Cable - Speed Control
    1. Remove the speed control actuator cable end from the throttle body. 1. Lift the speed control cable from the throttle nailhead. 2. Release the speed control cable from the throttle bracket. 2. Remove the speed control cable from the retaining cli ...

    Transmission (Assembly)
    Special Tool(s) Dial Indicator Gauge with Holding Fixture 100-002 (TOOL-4201-C) or equivalent Holding Fixture, Transmission 307-003 (T57L-500-B) Remover/Installer, Bearing Tube 308-024 (T75L-7025-B) Re ...

    Speed Control (Diagnosis and Testing)
    Refer to Wiring Diagrams Cell 31 , Speed Control for schematic and connector information. Special Tool(s) Worldwide Diagnostic System (WDS) 418-F224, New Generation STAR (NGS) Tester 418-F052, or equivalent diagnostic tool 7 ...