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:

    Exceptions To Normal Schedule
    Yellow Coolant Change coolant at 5 years or 160,000 km (100,000 miles) of the vehicle's life, whichever comes first. After the initial change, change coolant every 3 years or 80,000 km (50,000 miles) thereafter. Natural Gas and Propane Vehicles Insp ...

    Spring Codes
    The spring code portion of the vehicle certification (VC) label identifies both the front and rear springs. The first letter/number indicates the front spring code. The second letter/number indicates the rear spring code. Front springs - base part numbe ...

    Mass Air Flow (MAF) Sensor - 3.8L
    Removal CAUTION: The mass air flow (MAF) sensor hot wire sensing element and housing are calibrated as a unit and must be repaired as a complete assembly. Do not damage the sensing element (internal to housing) or possible failure to the mass air f ...