Traction Control Switch: Description and Operation

The traction control switch is a momentary contact switch read by the ABS controller, with the BCM controlling the status of the LED commanded by the ABS. When the light is On, traction system is enabled and with the light Off, the traction system is disabled. At engine start, (no malfunctions present) traction control system is enabled regardless of previous switch state and the BCM controller illuminates the TCS LED. The ABS controller continues to monitor TCS switch for a change in state. If traction control is disabled for any reason other than driver input (turning switch Off), the LED will be turned off and the malfunction indicator lamp or anti-lock telltale lamp will be turned On to indicate malfunction. At this time the ABS controller will store switch status as being On although system and LED are Off. This is to prevent repeated toggling of the TCS switch leaving switch status in Off when traction control becomes available again. If the malfunction goes away, the TCS LED will light and the TCS system will be enabled.