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:

    Camshaft Lobe Lift
    Special Tool(s) Dial Indicator Gauge with Holding Fixture 100-002 (TOOL-4201-C) or equivalent 1. Use a Dial Indicator Gauge with Holding Fixture to measure camshaft intake/exhaust lobe lift. Rotate the camshaft and subtract the lowest ...

    Cooling Fan Motor and Shroud
    Removal and Installation 1. Disconnect the battery ground cable. 2. Remove the degas bottle or coolant expansion tank. For additional information, refer to Degas Bottle-4.6L(2V) and 4.6L(4V) in this section. 3. Disconnect the cooling fan electrical connecto ...

    Heated seats
    WARNING: Persons who are unable to feel pain to the skin because of advanced age, chronic illness, diabetes, spinal cord injury, medication, alcohol use, exhaustion, or other physical conditions, must exercise care when using the seat heater. The seat heater m ...