Possible Causes

Malfunction is detected when an ON signal from stop lamp switch and ASCD brake switch are sent to ECM at the same time when vehicle speed is more than 19 MPH. Possible causes are:

• Stop lamp switch circuit open or shorted.
• ASCD brake switch circuit open or shorted.
• Defective ASCD brake switch.
• Defective stop lamp switch.
• Incorrect stop lamp switch installation.
• Incorrect ASCD brake switch installation.
• Defective ECM.