TRANSPORTING LOADS - Continued
When the towing vehicle and semitrailer are to be parked and left unattended, set the parking brake on the towing
vehicle. Apply the semitrailer parkbrake control, and turn off the engine before leaving the cab. Block the
semitrailer wheels with chock blocks. Block behind front wheels on uphill grades and in front of back wheels on
Visibility from towing vehicle is significantly reduced when backing, whether the semitrailer
is loaded or not. Operator must know where ground guide is at all times. Proper
procedures must be followed and extreme caution used when backing to prevent damage
to equipment. Failure to comply may result in death or injury to personnel. Seek medical
attention in the event of an injury.
When backing, use the assistant operator as a ground guide. Adjust rearview mirrors before backing. Use slow
speed and extreme caution when backing this combination.
END OF TASK
ANTI-LOCK BRAKING SYSTEM (ABS)
The ABS is an electronic system that monitors and controls wheel speed during braking and wheel lock
situations. The system improves vehicle stability and control by reducing wheel lock during braking. The
ABS includes an ECU that is combined with a dual modulator valve assembly. Four-wheel speed sensors
provide input to the ECU. When the ECU detects a wheel lockup during a hard braking situation, the ECU
activates the appropriate modulator valve to control air pressure to the braking system. The ECU is to be
replaced and is not serviced.
In the event of a malfunction in the ABS, the ABS in the affected wheel is disabled and that wheel still has
normal brakes. The other wheels keep the ABS function.
An ABS indicator lamp located on the left rear corner of the semitrailer lets the operator know through a
series of blink codes the status of the system on initial startup. For blink codes, refer to (WP 0060) .
END OF TASK