143H and 163H Motor Graders All Wheel Drive Caterpillar

In certain traction conditions, the operator may experience the front wheels "Hopping". Hopping occurs when the front wheels bounce off the ground. The all wheel drive electronic control module (ECM) monitors the pressure from the all wheel drive piston pump. The ECM will activate the "Hop Stop" when the pressure fluctuations occur twice in one second. The "Hop Stop" is deactivated when the AWD system is in the MANUAL mode. To maintain maximum tractive effort, the ECM uses the machine ground speed to determine the correct drive pressure. The all wheel drive piston pump is then set to obtain this pressure for two seconds.

At every twenty second interval, the counter records each activation of the "Hop Stop". This counter will be reset to zero under any of the following conditions:

• A twenty second period has ended.

• The operator moves the torque control lever to the minimum setting.

• Traction conditions have changed and the machine is not "Hopping".

When the ECM detects a "Hopping" mode three times within twenty seconds the ECM will allow the front wheels to continue to hop. If there is no change in operating conditions or traction conditions at this point, the operator must pull back on the torque control in order to restart the traction control.

The traction control for the front wheels is called "Hop Stop". The term "Hop Stop" is used on the Electronic Control Analyzer Programmer (ECAP) and on the Electronic Technician (ET).