ABS warning lamp: Notes

Fig 1: Identifying ABS Warning Lamp

Courtesy of SAAB-SCANIA OF AMERICA, INC.

Fig 2: Identifying Circuit Diagram - ABS Warning Lamp

Courtesy of SAAB-SCANIA OF AMERICA, INC.

The ABS or TC/ABS control module monitors the function of the ABS system and turns on the ABS warning lamp on the right-hand side of the main instrument unit if there is a problem.

When the ABS lamp lights up, the anti-lock braking system is disabled and the brakes work just like a conventional braking system.

On cars with ABS (non-bus system),  the ABS control module will ground pin 7 on the main instrument unit, whereby the control module will turn on the warning lamp.

On cars with TC/ABS (bus system),  the main instrument unit will receive information on the bus to turn on/off the lamp.

Fig 3: Identifying Communication Diagram - ABS Warning Lamp

Courtesy of SAAB-SCANIA OF AMERICA, INC.

Fig 4: Identifying Communication Circuit Diagram - ABS Warning Lamp

Courtesy of SAAB-SCANIA OF AMERICA, INC.

The TC/ABS control module turns on the lamp when the ignition is turned on and turns it off again after about 3 seconds provided there are no faults.

The brake fluid warning lamp and the central warning lamp will also come on when the ABS warning lamp comes on.