What is a Speed Control Deactivation Switch (SCDS)?
For several years, the SCDS was included in cruise control systems installed in Ford vehicles. In fact, it was supposed to provide a backup safety switch which would engage if the primary cruise control failed to disengage when the user pressed on the brake pedal. It was located on the end of the brake master cylinder.
If the cruise control system operates properly, it will disengage when the user presses down on the brake pedal. A sensor reacts to the added pressure, forcing two electrical contacts to open, thereby breaking a closed electrical circuit. When the circuit opens, the cruise control is designed to release. If the circuit fails to open or the cruise control fails to disengage, the backup SCDS should release the cruise control for the primary electrical deactivation switch.
Why do these switches cause fires?
When Texas Instruments developed the Speed Control Deactivation Switch, it was designed to run on a small intermittent DC load (1-2 amperes). However, Ford installed the switches into a 15-ampere continuous circuit. The 15-amp circuit was always on , regardless of whether the vehicle was turned on or the key was in the ignition. The SCDS is enclosed inside a plastic case designed to seal brake fluid out. CITATION For \l 1033 (Ford Speed Control Deactivation Switch Fires) Unfortunately, when the seal failed in several SCDS switches, the highly flammable brake fluid met the overheated switch. Deaths resulted in several states when vehicles parked inside garages caught fire in the middle of the night, setting the house on fire.
History of Complaints
The first recall related to this SCDS switch took place on May 13, 1999. At that time, Ford recalled 263,000 Lincoln Town Car, Ford Crown Victoria, and Mercury Grand Marquis. (Reis & O’Connor, 2006) Ford and the National Highway Transportation Safety Administration (NHTSA) investigated over 100 complaints during 1998 and 1999; however, Ford continued to install the same switches in Ford, Lincoln and Mercury vehicles through model year 2004.
In 2001, the NHTSA opened a new investigation after receiving 12 complaints of fires starting in engine compartments. Two fires resulted in homes burning to the ground when vehicles parked in garages caught fire. All 12 vehicles were outside the scope of the original recall. Despite their findings, the NHTSA concluded “a safety-related defect trend has not been identified and further use of agency resources does not appear to be warranted.” (Ford Cruise Control Deactivation Switch Recalls and History, 2010)
Not six months later, the NHTSA began another investigation into SCDS fires in Ford F-150, Expedition, and Lincoln Navigators. This investigation covered 36 fires in engine compartments while the vehicles were off and parked. This investigation did result in the recall of all trucks and SUVs named in the investigation. At this time, the NHTSA reported 218 fires in vehicles outside the original recalls. Public pressure and continuing reports of fires in SCDS switches forced Ford to make three additional recalls.
Why Don’t All Vehicles Equipped with an SCDS Catch Fire?
Vehicles built with the Speed Control Deactivating Switch will not catch fire if they do not leak brake fluid. When brake fluid meets an overheating SCDS, fire can occur.
Warning Signs That Your SCDS May Be At Risk of Failing
If your vehicle was built during these years but has not been recalled, there are several warning signs you should be aware of:
- Cruise control does not seem to work properly (usually disengaging while you are driving in cruise control),
- Your vehicle shows evidence of brake fluid leaking from the SCDS,
- Your vehicle seems to have trouble shifting out of park,
- Brake lights work sporadically,
- Brake warning lights come on intermittently,
- Battery won’t hold a charge,
- Blown fuse #12, (Reis & O’Connor, 2006) or
- If a mechanic tells you the fuse for the cruise control has melted.
If any of the listed warning signs apply to your Ford vehicle built between 1992 and 2004, contact your local Ford dealership to discuss eligibility for repair.
Check to see if your vehicle is included on the SCDS recall list. If your Ford vehicle has incurred a fire that you have not reported, the incident should be reported to Ford and The National Transportation Safety Board. Our Firmreviews cases involving Ford SCDS defects. If you have experienced a fire related to an unexplained fire in the engine compartment of your vehicle, we would like to help you determine whether a product defect was responsible for your loss.
BIBLIOGRAPHY Ford Cruise Control Deactivation Switch Recalls and History. (2010, Feb 22). Retrieved from The Center for Auto Safety: https://www.autosafety.org/ford-cruise-control-deactivation-switch-recalls-and-history/
Ford Speed Control Deactivation Switch Fires. (n.d.). Retrieved from Garrett Engineers, Inc: http://garrett-engineers.com/2008/11/ford-speed-control-deactivation-switch-fires/
Reis, J. W., & O’Connor, C. (2006, Spring/Summer). Ford’s Speed Control Deactivation Switch — Out of Control?Retrieved from NASP Subrogator: https://subrogation.org/download/article/Ford’s%20Speed%20Control%20Deactivation%20Switch–Out%20Of%20Control.pdf