Possible Causes

Malfunction is detected when vehicle speed is above 19 MPH and on signals from stop lamp switch and ASCD brake switch are sent to ECM at the same time. Possible causes are:

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