ABS Telltale Indicator Lamp

The ABS telltale indicator lamp is turned On by the Antilock Brake System (ABS) control module. The ABS control module controls the ABS telltale indicator lamp through the telltale control logic on the I/P cluster speedometer printed circuit board. When the ABS control module grounds the input of the cluster, the transistor is Off and the ABS telltale is Off. If the ABS control module ungrounds the circuit, or the circuit becomes open and ignition voltage is present at the cluster, the transistor turns On and the ABS telltale indicator comes On.

The ABS telltale indicator lamp is turned On, for approximately two seconds, during engine start-up by the ABS control module for a bulb check.

If the telltale comes on solid, it informs the driver that a problem has occurred and that the ABS system has been disabled. The vehicle should be taken in for service as soon as possible.

The telltale will flash in only one case. If DTC 87 is set, and subsequently during the same ignition cycle a fault occurs such that the rear motor is not at home the telltale will flash. On subsequent ignition cycles, the ABS telltale will be on solid. When the rear motor is not at home, the car does not have rear brakes. Consequently, the ABS control module will turn on the BRAKE telltale.

For DTCs 11, 13, 75, 87 and 94, the ABS control module will not be able to turn the ABS telltale on, but will send a message to the PCM through the class 2 data bus (circuit 1807) to turn on the SERVICE (Wrench) telltale.