Display Message:
52 STR ENCODER FAULT
CALL SERVICE

Description:
The steer controller or caster controller has sensed a fault in the tiller encoder.

Symptom:
If moving, the speed command is set to zero, the electric brake is enabled, and the truck is disabled. If the fault is sensed at truck startup, vehicle systems will not be engaged.

Probable Causes and Test Procedures:
Verify 5 volts on pin #3 of the steering controller. If voltage is not present, check the steer controller for B+ voltage at the B+ terminal. Check the LED for solid light.
If voltage is good on pin #3, check voltage at pin #1 to the steer encoder unit, pin #B to th epressure transducer, and pin #1 (wire 250A) to the steer motor.
If any circuit is open, check the wiring harness for continuity. Inspect for loose or damaged pin connectors and for broken or damaged wires.
If voltage is less than 5 volts at any point, check for a grounded circuit by disconnecting the following components one at a time:
Steer Motor Connection
Pressure Transducer Connection
Steer Encoder Connection
Any voltage drop should be determined and the affected part replaced as necessary.
Check the continuity of all wiring from the steering encoder connections to the steering controller, steering pressure transducer and the steer motor.
Check voltage on wire #573, wire #574, wire #575, and wire #576.
Voltage on each wire should switch back and forth between 5 volts and 0 volts as the steering encoder is slowly rotated.
If voltage on all wires stays at 5 volts and 0 volts as the steering encoder is rotated, replace the steering encoder.