General Assist Technical Reference
Mobile Technician App
Fault-code lookup, troubleshooting and diagnostic conversion tools
For Fujitsu General standard products, AIRSTAGE VRF systems and wireless LAN adaptors
The Mobile Technician App is a field-support tool designed to help qualified technicians diagnose faults across a broad range of Fujitsu General air-conditioning products. It provides fault-code guidance, troubleshooting information and practical conversion utilities in one mobile application.
1. Key features
| Feature | Description |
|---|---|
| Fault-code lookup | Search fault codes for many current Fujitsu General standard air-conditioning and AIRSTAGE VRF models. |
| Troubleshooting guidance | Provides model- and error-specific checks to support structured fault diagnosis. |
| Thermistor conversion | Converts thermistor temperature, resistance and voltage values to assist with sensor testing. |
| Pressure-sensor conversion | Converts pressure-transducer return voltage into an approximate operating pressure. |
| Wireless LAN adaptor support | Includes troubleshooting information for supported wireless LAN adaptors. |
| VRF function-setting documents | Provides reference material for selected AIRSTAGE VRF function settings. |
2. Download the app
The Mobile Technician App is available from the Apple App Store and Google Play.
App availability: Store availability, supported operating-system versions and app content may change. Confirm that the app is published by Fujitsu General Limited before installation.
3. How to use the app
- Install and open the app. Select the applicable product category, such as RAC/PAC, VRF or Wireless LAN Adaptor.
- Identify the model and fault. Enter or select the model information and fault code shown by the unit or controller.
- Review the troubleshooting guidance. Follow the checks in the sequence provided and compare results with the relevant service manual.
- Use the conversion tools where required. Enter measured thermistor resistance, sensor voltage or pressure information to support diagnosis.
- Confirm the repair. Rectify the identified issue, clear the fault where applicable and complete an operational test.
4. Common diagnostic applications
LED fault-code identification
Use the app to interpret indoor-unit, outdoor-unit or controller LED flash patterns and identify the relevant error category.
Use the app to interpret indoor-unit, outdoor-unit or controller LED flash patterns and identify the relevant error category.
Thermistor validation
Compare the sensor temperature with measured resistance or return voltage to determine whether the thermistor is operating within its expected range.
Compare the sensor temperature with measured resistance or return voltage to determine whether the thermistor is operating within its expected range.
Pressure-transducer checks
Convert the sensor's DC return voltage into an approximate system pressure and compare it with gauge readings and expected operating conditions.
Convert the sensor's DC return voltage into an approximate system pressure and compare it with gauge readings and expected operating conditions.
VRF configuration reference
Access selected function-setting information when commissioning or reviewing AIRSTAGE VRF system configuration.
Access selected function-setting information when commissioning or reviewing AIRSTAGE VRF system configuration.
5. Important technical notes
Qualified technicians only: The app is a diagnostic aid and does not replace electrical isolation, safe-work procedures, the applicable installation or service manual, or technicians' licensing obligations.
- Confirm the full indoor and outdoor model numbers before relying on a fault-code result.
- Use the service manual and wiring diagram applicable to the exact model and production revision.
- Conversion values are diagnostic references and should be assessed alongside actual operating conditions.
- Isolate power and safely discharge high-voltage capacitors before disconnecting or resistance-testing components.
- Do not replace a PCB or component solely on the basis of a displayed fault code; complete the prescribed supporting checks first.
- For unresolved faults, contact Fujitsu General Technical Support with the complete model numbers, serial numbers, fault history and test results.
This article is intended as a quick field reference. Always use the latest model-specific technical documentation and applicable safety requirements.