Gas detectors
MSA ULTIMA X5000 Gas Monitor fault codes
What all 39 MSA ULTIMA X5000 Gas Monitor fault codes mean, in plain words, with a risk grade for each. These come from the manufacturer's own manual. The fix for each one is in WERCS Diagnose.
Get the fixes · plans from $49/moUpdated November 4, 2026
| Code | What it means | Risk |
|---|---|---|
| LOC | LOC The gas monitor measured a combustible sensor over range condition, causing the instrument to alarm. | RED |
| ACT Fault | ACT Fault The gas monitor has an out of range measurement, causing the instrument to fault. | YELLOW |
| Lamp Fault | Lamp Fault The gas monitor sensor lamp is not operating properly, causing the instrument to fault. | YELLOW |
| Over Range | Over Range The gas monitor detects an over scale gas reading, causing the instrument to trigger an alarm. | RED |
| Relay Fault | Relay Fault The gas monitor has detected a problem with the relays, causing the output switching to fail. | YELLOW |
| EEPROM Fault | EEPROM Fault The gas monitor has a memory error, causing the instrument to fault and stop working. | YELLOW |
| Channel Error | Channel Error The gas monitor has an error in the output system, causing the signal transmission to fail. | YELLOW |
| Unknown Error | Unknown Error The gas monitor sensor is returning an unknown error condition, causing the instrument to fault. | YELLOW |
| Negative Drift | Negative Drift The gas monitor sensor is reading downscale, meaning the instrument will provide inaccurate gas measurements. | YELLOW |
| Sensor Missing | Sensor Missing The gas monitor sensor is no longer detected, causing the instrument to fault and stop reading. | YELLOW |
| Beads Off Fault | Beads Off Fault The combustible sensor beads are turned off, which prevents the monitor from detecting gas. | YELLOW |
| Sensor RAM Error | Sensor RAM Error The gas monitor sensor detected a bad memory location, causing the instrument to fault. | YELLOW |
| Reference Failure | Reference Failure The gas monitor has an out of range measurement, causing the instrument to fault. | YELLOW |
| TEDS CRC-16 Error | TEDS CRC-16 Error The gas monitor sensor datasheet is invalid, causing the instrument to fault. | YELLOW |
| Low Signal Failure | Low Signal Failure The gas monitor sensor output is low, causing the instrument to fault and read inaccurately. | YELLOW |
| RAM Checksum Fault | RAM Checksum Fault The gas monitor detected a bad memory location, causing the instrument to fault. | YELLOW |
| Sensor FLASH Error | Sensor FLASH Error The gas monitor has a sensor program error, causing the instrument to fault. | YELLOW |
| Configuration Fault | Configuration Fault The gas monitor has detected an incorrect configuration, causing the instrument to fault. | YELLOW |
| Sensor Heater Fault | Sensor Heater Fault The gas monitor sensor heater is not working properly, causing the instrument to fault. | YELLOW |
| Calibration Required | Calibration Required The gas monitor sensor requires calibration, meaning it will not read gas levels accurately until completed. | YELLOW |
| Flash Checksum Fault | Flash Checksum Fault The gas monitor has an incorrect main circuit board program, causing the instrument to fault. | YELLOW |
| General System Error | General System Error A gas monitor internal power supply is out of range, causing the instrument to fault. | YELLOW |
| Sensor Element Error | Sensor Element Error The gas monitor sensor is broken, causing the instrument to fault and stop detecting gas. | YELLOW |
| Supply Voltage Fault | Supply Voltage Fault The gas monitor input power supply is out of range, causing the instrument to fault. | YELLOW |
| Life and Health Fault | Life and Health Fault The gas monitor sensor is at the end of its life, causing the instrument to fault. | YELLOW |
| Negative Supply Fault | Negative Supply Fault The gas monitor negative power supply is out of range, causing the instrument to fault. | YELLOW |
| Sensor Internal Fault | Sensor Internal Fault The gas monitor has a hardware issue in the sensor, causing the instrument to fault. | YELLOW |
| Internal Circuit Fault | Internal Circuit Fault The gas monitor has a hardware failure on the main circuit board, causing it to fault. | YELLOW |
| Parameter out of range | Parameter out of range A gas monitor setting is improperly configured, causing the instrument to fault. | YELLOW |
| Span Calibration Fault | Span Calibration Fault The gas monitor sensor failed the span calibration operation, causing the instrument to fault. | YELLOW |
| Zero Calibration Fault | Zero Calibration Fault The gas monitor sensor failed the zero calibration operation, causing the instrument to fault. | YELLOW |
| Parameter Fault (Sensor) | Parameter Fault (Sensor) A gas monitor sensor setting is improperly configured, causing the instrument to fault. | YELLOW |
| Sensor End of Life Fault | Sensor End of Life Fault The gas monitor sensor has reached the end of its life, causing the instrument to fault. | YELLOW |
| Sensor Configuration Reset | Sensor Configuration Reset The sensor datasheet was cleared to factory defaults, which requires the monitor to be configured again. | YELLOW |
| Diffusion Supervision Fault | Diffusion Supervision Fault The gas monitor sensor has detected a blockage in the gas path, causing the instrument to fault. | YELLOW |
| Sensor Supply Voltage Fault | Sensor Supply Voltage Fault The gas monitor sensor input voltage is out of range, causing the instrument to fault. | YELLOW |
| External Memory Access Error | External Memory Access Error The gas monitor had an error communicating with its memory, causing the instrument to fault. | YELLOW |
| Both side green LEDs blinking | Gas value is still shown. The gas monitor recommends a calibration, meaning the instrument will display a warning. | GREEN |
| External Memory Checksum Error | External Memory Checksum Error The gas monitor memory is not valid, causing the instrument to fault and stop working. | YELLOW |
Every code comes from the manufacturer's own manual. Subscribers see which manual and page.