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:

    Pinpoint Test O: DTC B1870 - Air Bag Indicator Shorted to Battery
    Normal Operation The air bag indicator is designed to illuminate for 6 (+/-2) seconds when the ignition switch is turned to the RUN position. This initial 6 seconds of illumination is considered normal operation and is called proveout of the air ba ...

    Flywheel Runout Check
    Special Tool(s) Dial Indicator/Magnetic Base 100-D002 (D78P-4201-B) or equivalent 1. Mount the special tool so that the indicator contact point rides on the clutch disc contact surface. 2. Turn the flywheel (6375); if the runout exceeds the ...

    Driveline Angle
      Item Description 1 Bottom of the frame 2 Engine crankshaft centerline 3 Engine angle 4 Driveshaft and coupling shaft centerline 5 Driveshaft and coupling shaft angle 6 Rear axle pinion centerline ...