Encoder System Down Failure

Modified on Fri, 26 Jan at 8:37 AM


Applicable Errors: 

85404671 - J1 encoder system down  

85404672 - J2 encoder system down 

85404673 - J3 encoder system down 

85404674 - J4 encoder system down 

85404675 - J5 encoder system down 

85404676 - J6 encoder system down 

85404677 - J7 encoder system down 

85404678 - J8 encoder system down 


Error Description: 

Failed to read the encoder information of the corresponding axis. 


Possible Causes: 

1.Dead Batteries in the robot. Batteries inside of the robot operate at 3.6V +/- 20%. If the batteries are low the batteries in the robot arm need to be replaced, the affected encoder(s) need to be reset, cycle power on the controller,   


2. A motor was changed or was unplugged from the wiring harness inside of the robot arm. To resolve this error - confirm affected joints, reset encoder(s), cycle power on the controller, and calibrate robot.  


3.Temporary disconnection of the power conversion board inside of the robot.  


4. A motors encoder has become damaged. Exchange the motor, reset encoder, calibrate affected joint. 




Identify and resolve the cause of the error and then reset the encoder using the guide below

Tools and Parts Needed

Full Sized Teaching Pendant  

Step by Step Guide

Step 1 

Confirm affected joint(s) by using the full sized teaching pendant 

Displaying Encoder Information (denso-wave.com) 

Step 2 

Identify the affected joint(s) 

Joint(s) affected by this error can be identified by a red circle in the System Status column.  

Step 3 

Reset encoder(s) for affected joint(s) 

 Resetting Encoder (RC8 / RC8A) : DENSO Robotics KB (freshdesk.com) 

Step 4 

Cycle power on your controller. 

Step 5 

Calibrate all joints that were reset.

How do I perform a CALSET for the robot? : DENSO Robotics KB 

Next Steps:

  • For repair options in the Americas please contact support@densorobotics.com 

  • For repair options outside of the Americas, please contact your local Denso Service Center.

Owner's Manual Reference

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