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:

    Valve Spring Strength
    Special Tool(s) Pressure Gauge, Valve/Clutch Spring 303-006 (TOOL-6513-DD) or equivalent 1. Use a Valve/Clutch Spring Pressure Gauge to check the valve spring for correct strength at the specified valve spring length. Refer to the appr ...

    Axle Housing
    Removal and Installation 1. CAUTION: The vehicle must be on level ground and at curb height. Mark the rear shock absorbers relative to their protective sleeve.  During installation, raise the suspension to this reference mark before tightening the s ...

    Lighting control
    A. Off B. Parking lamps, instrument panel lamps, license plate lamps and tail lamps C. Headlamps High Beams • Push the lever toward the instrument panel to switch on the high beams. • Pull the lever toward you to switch of the high beams. Headlamp Flashe ...