Repair manual

Steering and Pitch Control CRT Repair

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7.10 “Limp Home” Mode

During normal operation, the green status indicator light (a) will remain

on. When the green status indicator light flashes, this indicates the

trowel is operating in the “limp home” mode. The “limp home” mode

signifies a fault with the load pin(s). In the “limp home” mode, the load

pins no longer provide feedback to the microprocessor. This condition

can occur if a load pin is damaged, its wiring has an open circuit, or its

wiring has a short circuit. The “limp home” mode is designed to allow

the operator to continue steering the trowel, at a reduced level of

control, until a repair can be made. In the “limp home” mode, the

actuators are still driven in or out by joystick movement; however, the

actuator does not return to the home (center) position when the

joystick is released. There is no automatic home (center) position for

the actuators; the joysticks must be used for every actuator movement.

For example, if the joysticks are positioned in a full forward position,

the microprocessor will send voltage to the actuator motor. With no

feedback from the load pin, the microprocessor cannot tell when the

actuator has reached the desired position and thus will continue to

send voltage to the actuator motor as long as the joystick is moved

from its home position. When the joystick is released, the joystick

returns to its home position; however, the actuators do not. They will

remain in the full-forward position. The joysticks must be used to

manually bring the actuators back to neutral by oversteering in the

opposite direction.

The trowel’s steering system is calibrated at the factory and should not

normally require calibrating. However, if a damaged load pin is

detected, calibration may be required. Calibration may be done by

contacting your local Wacker Corporation authorized service dealer.

7.11 Error Codes

The red indicator light (b) is used to communicate system faults. A

specific sequence of flashes of the red indicator light is used to identify

each fault. The sequence of flashes is known as the error code. There

are 17 distinct error codes. Error code sequence:

• long pause

• 1 to 4 flashes

•short pause

• 1 to 3 flashes

•short pause

• 1 to 5 flashes

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