Scan Tool Testing and Procedures

The following ABS data definitions are intended to assist in understanding the data displayed by a scan tool when it is communicating with the ABS controller. A thorough understanding of this data will not only aid in diagnosing ABS related problems, but will also help eliminate repairs.


T-CODES/FLAGS
^ Displays a YES with codes or flags are present in the ABS controller.

LF WHEEL SPD MPH
^ Displays the speed of the left front wheel.

RF WHEEL SPD MPH
^ Displays the speed of the right front wheel.

LR WHEEL SPD MPH
^ Displays the speed of the left rear wheel

RR WHEEL SPD MPH
^ Displays the speed of the right rear wheel.

VEHICLE REF MPH
^ Displays the filtered average of all four wheel sped sensors.

LF SOLENOID
^ Displays the status of the left front ABS solenoid. The solenoid is On during an ABS stop.

RF SOLENOID
^ Displays the status of the right front ABS solenoid. The solenoid is On during an ABS stop.

LF COMMANDED AMPS
^ Displays the left front desired motor current during an ABS stop.

LF SENSED AMPS
^ Displays actual left front motor current during an ABS stop.

RF COMMANDED AMPS
^ Displays the right front desired motor current during an ABS stop.

RF SENSED AMPS
^ Displays actual right front motor current during and ABS stop.

REAR COMMANDED
^ Displays in amps, the rear desired motor current during an ABS stop.

REAR SENSED
^ Displays in amps, the rear actual motor current during an ABS stop.

BATTERY ENABLE
^ Displays the ignition voltage to the ABS control module.

LF BRAKE
^ Displays the left front motor direction (up or down) during an ABS stop.

RF BRAKE
^ Displays the right front motor direction (up or down) during an ABS stop.

BRAKE SWITCH
^ Displays the current status of the brake switch, On or Off.

BRAKE SWITCH CYCLE
^ Displays YES if the brake switch has been cycled this ignition cycle.

BRAKE SWITCH OPEN
^ Displays YES when an open brake switch circuit is detected.

ABS TT
^ Displays On when ABS telltale is being commanded on by the ABS control module.

ABS TT FLASHING
^ Displays On when the ABS telltale is flashing.

ENABLE RELAY
^ Displays the status of the ABS enable relay.

ABS STOP
^ Displays YES when the vehicle is in an ABS stop.

BRAKE TT
^ Displays On when the brake telltale is on.

BRAKE TT OPEN
^ Displays On when an open brake telltale circuit is detected.

25 MPH REACHED
^ Displays On when the vehicle has reached 40 km/h (25 mph) during this ignition cycle.