Komatsu D155AX-7 Dozer Service Manual

Table of Contents

• Index and Foreword
• Specification
• Structure and Functions
• Standard Value Table
• Testing and Adjusting
• Troubleshooting
• Disassembly and Assembly
• Appendix
• Circuit Diagrams
• Index

Procedure for testing and troubleshooting
The air conditioner is provided with self-diagnosis functionality in order to provide for inspection of its main components. Specifically, the operation of sensors and servomotors can be examined.
If a troubled section is detected, every part of that section must be inspected.

1. After basic check, find the troubled section according to the detected trouble of the air conditioner.

2. Narrow down the sections with the self-diagnosis function (See “Check with self-diagnosis”).
If, however, the entire air conditioner unit fails to operate, inspect for problems with the supply of power to the air conditioner controller and with CAN communication between the machine monitor and the air conditioner controller.
If any part of the air conditioner unit can operate, it will indicate that the air conditioner controller is receiving power normally and that CAN communication between the machine monitor and the air conditioner controller is normal.

3. After finding out the troubled section, inspect the component parts in that section and repair the troubled part.