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:

    Instrument Cluster Replacement
    When it is necessary to install a new instrument cluster, contact the Instrument Cluster Program. Gauge Indication Systems Tachometer Engine rpm information is relayed to the instrument cluster from the powertrain control module (PCM) over the standard ...

    Gauges
    Type 1 Cluster shown in standard measure. Metric similar. A. Speedometer B. Fuel gauge C. Engine coolant temperature gauge D. Tachometer E. Information display. See Information displays for more information. Fuel Gauge Indicates approximately how much fuel i ...

    Road Test
    NOTE: It may be necessary to have the customer ride along or drive the vehicle to point out the concern. During the road test, take into consideration the customer's driving habits and the driving conditions. The customer's concern just may be an acceptable ...