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:

    Air Conditioning (A/C) System Flushing
    Special Tool(s) A/C Flush and Purge Machine 219-00022 (part of 219-00023) or equivalent A/C Flush and Purge Fitting Kit 219-00024 (part of 219-00023) or equivalent WARNING: Use extreme care and observe all safety and service ...

    Disc Check
    Special Tool(s) Brake/Automobile Brake Drum System with Vacuum 164-R3622 or equivalent Dial Indicator/Magnetic Base 100-D002 (D78P-4201-B) or equivalent WARNING: Dust and dirt present on wheel brake and clutch assemblies may ...

    Exhaust System Neutralizing
    WARNING: Exhaust gases contain carbon monoxide, which is harmful to health and potentially lethal. Repair exhaust system leaks immediately. Never operate the engine in an enclosed area. WARNING: Exhaust system components are hot. NOTE: Neutralize the exhau ...