| Document type | Installation Operation and Maintenance Guide |
|---|---|
| Document number | 201.47-ICOM1.EN.CE |
| Equipment | YVAA Style B |
| Brand | YORK |
| Revised | 2026-01-13 |
| File size | 9.2 MB |
Fault codes in this document
Safety update error messages
| Code / display | Meaning | Cause | Action | Page |
|---|---|---|---|---|
| MORE THAN ONE FILE FOUND PRESS THE ENTER KEY TO CONTINUE X | Software update aborted; panel waits for operator acknowledgement. | More than one *.bin file found on the selected SD card or USB device. | Press the ENTER key to return to the previous screen (software download). | 190 |
| FILE NOT FOUND PRESS THE ENTER KEY TO CONTINUE X | Software update aborted; panel waits for operator acknowledgement. | No *.bin file on the selected device. | Press the ENTER key. | 190 |
| FILE NOT ABLE TO BE LOADED PRESS THE ENTER KEY TO CONTINUE X | Software update aborted; panel waits for operator acknowledgement. | The *.bin file is not able to be loaded to SPI flash, for example if the embedded checksum verification fails. | Press the ENTER key. | 190 |
| SELECTED DEVICE NOT FOUND PRESS THE ENTER KEY TO CONTINUE X | Software update aborted; panel waits for operator acknowledgement. | User tried to update the software without inserting an SD or USB device. | Press the ENTER key. | 190 |
| FLASH ERROR XX PRESS THE ENTER KEY TO CONTINUE X | Other internal errors during the update; XX corresponds to the flash card update error codes of Table 24. | Other internal errors. | Press the ENTER key. | 190 |
| 10 | Flash card update error code: Flash card not found. | Never reset or power down the chiller until the update is finished. Interrupting the flash update procedure can corrupt the program file and render the control board inoperative. | 189 | |
| 11 | Flash card update error code: SOFTWARE.ELF file not found. | Never reset or power down the chiller until the update is finished. Interrupting the flash update procedure can corrupt the program file and render the control board inoperative. | 189 | |
| 14 | Flash card update error code: SOFTWARE.ELF file larger than expected. | Never reset or power down the chiller until the update is finished. Interrupting the flash update procedure can corrupt the program file and render the control board inoperative. | 188 | |
| 15 | Flash card update error code: RAM to IPU Flash transfer of DATABASE.BIN failed. | Never reset or power down the chiller until the update is finished. Interrupting the flash update procedure can corrupt the program file and render the control board inoperative. | 188 | |
| 16 | Flash card update error code: RAM to IPU Flash transfer of SOFTWARE.ELF failed. | Never reset or power down the chiller until the update is finished. Interrupting the flash update procedure can corrupt the program file and render the control board inoperative. | 188 | |
| 17 | Flash card update error code: Could not allocate sufficient memory to read or write file. | Never reset or power down the chiller until the update is finished. Interrupting the flash update procedure can corrupt the program file and render the control board inoperative. | 188 | |
| 99 | Flash card update error code: Internal software error. | Never reset or power down the chiller until the update is finished. Interrupting the flash update procedure can corrupt the program file and render the control board inoperative. | 190 |
Unit warning
| Code / display | Meaning | Cause | Action | Page |
|---|---|---|---|---|
| UNIT WARNING: !! LOW BATTERY !! CHECK SETPOINTS/PROGRAM/OPTIONS/TIME | RTC battery low detected at power-up. All programmed setpoints, program values, time, schedule, and history buffers are lost and reset to default values, which may not be the appropriate operating values. Unit is prevented from running. Warning displays indefinitely; warnings are not logged to the history buffer. | RTC battery voltage low / bad battery, checked when powering up the micropanel. | Replace the battery as soon as possible; the unit cannot run on the next power interruption until values are restored. After detecting a bad battery the unit is prevented from running until the MANUAL OVERRIDE key is pressed; anti-recycle timers are then set to the programmed default anti-recycle time so the operator has time to check setpoints, program values and other parameters. | 191 |
| UNIT WARNING: INVALID NUMBER OF COMPRESSORS SELECTED | Warning displayed indefinitely; invalid number-of-compressors-selected configuration. | Occurs after initializing the VSD if no number-of-compressors-select jumpers are installed, or if more than 1 jumper is installed. | To clear the warning, turn off both the control panel and VSD control voltage and ensure the jumpers are correctly installed in the VSD wiring harness. Jumpers are factory installed in the wire harness plug and do not require changes. | 191 |
| UNIT WARNING: INVALID SERIAL NUMBER ENTER UNIT SERIAL NUMBER | May mean the chiller has lost important factory-programmed information; the serial number and other important data may need to be reprogrammed. | Invalid / lost serial number data. | Immediately contact Johnson Controls Product Technical Support. Enter the serial number using the service key (date and time must be set on the chiller before programming; factory-provided password required). This status message can be bypassed to view additional messages under the STATUS key by pressing the STATUS key repeatedly. | 191 |
| UNIT WARNING QUARTERLY SERVICE REQUIRED – CONTACT JCI | Quarterly service reminder. Warnings are not logged in the history buffer. | Days since the last service exceed 90 days. | When quarterly service is complete, set the days to zero after clearing the warning. | 191 |
| Unit WARNING YEARLY SERVICE REQUIRED – CONTACT JCI | Yearly service reminder. Warnings are not logged in the history buffer. | Days since the last service exceed 365 days and the operating hours since the last service exceed 2,890 hours. | When the yearly service is complete, set the days to zero after clearing the warning. | 192 |
| UNIT WARNING 3 YEAR SERVICE REQUIRED – CONTACT JCI | 3 year service reminder. Warnings are not logged in the history buffer. | Days since the last service exceed 1,095 days. | When the 3 year service is complete, set the days to zero after clearing the warning. | 192 |
| UNIT WARNING 5 YEAR SERVICE REQUIRED – CONTACT JCI | 5 year service reminder. Warnings are not logged in the history buffer. | Days since the last service exceed 1,825 days. | When the 5 year service is complete, set the days to zero after clearing the warning. | 192 |
Unit safeties
| Code / display | Meaning | Cause | Action | Page |
|---|---|---|---|---|
| UNIT YYYYYYYY HIGH AMBIENT TEMP | Ambient temperature above allowable range; chiller shuts down with a controlled ramped shutdown. Fault message present only while the ambient temperature is causing the fault condition. | Ambient temperature rises above 55°C. | Auto-reset: restart occurs automatically, if demand allows, when temperature falls 1.1°C below the cutout of 53.9°C. Cannot cause a lockout. Unit is inhibited from starting any time the temperature is above 53.9°C. | 192 |
| UNIT YYYYYYYY LOW AMBIENT TEMP | Ambient temperature below the programmable Low Ambient Temp Cutout; chiller shuts down with a controlled ramped shutdown. Fault message present only while the ambient temperature is causing the fault condition. | Ambient temperature falls below the programmable Low Ambient Temp Cutout. Fault only occurs if the Low Ambient Cutout is ENABLED under the OPTIONS key. | Auto-reset: restart can occur, if demand allows, when temperature rises 1.1°C above the cutout. Cannot cause a lockout. Unit is inhibited from starting any time the temperature is below the cutout plus 1.1°C. | 192 |
| UNIT YYYYYYYY LOW LEAVING CHILLED LIQUID TEMP | Leaving chilled liquid temperature below the programmable cutout; helps protect the chiller from an evaporator freeze-up; chiller faults and shuts down with a controlled ramped shutdown. | Leaving chilled liquid temperature (water or brine) drops below the programmable cutout point — situation could occur under low flow conditions or if the Micro Panel setpoint values are improperly programmed. | Auto-reset: restart can occur, if demand allows, when chilled liquid temperature rises 2.2°C above the cutout. Cannot cause a lockout. Unit is inhibited from starting any time the chilled liquid temperature is below the cutout plus 2.2°C. | 193 |
| UNIT YYYYYYYY VSD COMMUNICATIONS FAILURE | Prevents the unit from trying to run if the Chiller Control Board never initializes communications with the VSD Logic Board; shuts down all compressors with a controlled ramped shutdown if communications are lost while operating. | On power-up, no reply from the VSD Logic Board within 8 s; or during normal operation, no valid response to messages for 8 s. | Unit is inhibited from starting until communications is established. Auto-reset: fault automatically resets when the Chiller Control Board receives a valid response from the VSD for a data request. VSD-related unit fault: if any 3 VSD unit faults occur within 90 min the unit locks out on the last fault; a VSD lockout requires a manual reset — both system switches must be cycled OFF and ON. | 193 |
System safeties, faults
| Code / display | Meaning | Cause | Action | Page |
|---|---|---|---|---|
| SYS X YYYYYYYY HIGH DISCHARGE PRESSURE | High Discharge Pressure Cutout (software fault); system faults and shuts down with a controlled ramped shutdown. | Discharge pressure rises above the programmed discharge pressure cutout for 0.5 seconds. | System allowed to restart when discharge pressure falls below the programmed cutout − 2.07 bar; inhibited from starting above cutout − 2.07 bar. Auto-reset after the 120 s anti-recycle timer; locks out on the 3rd fault within 90 min — cycle the respective system switch OFF and ON to clear. | 194 |
| SYS X YYYYYYYY HPCO FAULT | Mechanical high pressure cutout (hardware) protecting the system from dangerously high discharge pressure; system faults and shuts down immediately. | Mechanical HPCO contacts open (opens at 23.2 barg ± 0.55 barg; closes at 17.4 barg ± 0.69 barg). Wired in series with the VSD Run Signal; only checked when the system is running. Fault occurs immediately, does not wait 3 s. | Auto-reset after the 120 s anti-recycle timer; locks out on the 3rd fault within 90 min — cycle the respective system switch OFF and ON to clear. | 194 |
| SYS X YYYYYYYY LOW SUCTION PRESSURE | Programmable Low Suction Pressure Cutout; protects the chiller from an evaporator freeze-up if the system attempts to run with a low refrigerant charge. | Suction pressure falls below the ramped Suction Pressure Cutout during the startup ramp, or below the programmed Suction Pressure Cutout after the ramp. Cutout is ignored at system start for the programmable Suction Pressure Startup Bypass Time, then linearly ramped from 10% to 100% of the programmed Suction Pressure Cutout. | Causes a lockout on the 3rd fault in 90 min — cycle the respective system switch OFF and ON to clear. | 194 |
| SYS X YYYYYYYY LOW SUCT PRES SMART FREEZE | Smart freeze safety fault. | Suction Pressure below the Suction Pressure Override Threshold longer than the programmable Smart Freeze Timer. Override Threshold = Suction Pressure Cutout + 11.72 kPa (R-134a), + 12.41 kPa (R-513A), + 8.96 kPa (R-1234ze). | Safety released when Suction Pressure ≥ Suction Pressure Override Threshold. Causes a lockout on the 3rd fault in 90 min — cycle the respective system switch OFF and ON to clear. | 194 |
| SYS X YYYYYYYY LOW MOTOR CURRENT | Motor Current Cutout; shuts the system down with a controlled ramped shutdown. | Microprocessor detects absence of motor current (less than 10% FLA), usually indicating that a compressor is not running. Safety ignored for the first 10 s of operation. | Auto-reset after the 120 s anti-recycle timer; locks out on the 3rd fault within 90 min — cycle the respective system switch OFF and ON to clear. | 195 |
| SYS X YYYYYYYY HIGH DIFF OIL PRESSURE | High Differential Oil Pressure Cutout; protects the compressor from low oil flow and insufficient lubrication; shuts down with a controlled ramped shutdown. | Discharge-to-Oil differential pressure rises above the cutout of 4.48 barg (measures the pressure drop across the oil filter — possibly a dirty oil filter). Safety ignored for the first 90 s of run time. | Auto-reset after the 120 s anti-recycle timer; locks out on the 3rd fault within 90 min — cycle the respective system switch OFF and ON to clear. | 195 |
| SYS X YYYYYYYY LOW DIFF OIL PRESSURE | Low Differential Oil Pressure Cutout; protects the compressor from low oil flow and insufficient lubrication; ensures the compressor is pumping sufficiently to push oil through the oil cooling circuit and internal lubrication system; shuts down with a controlled ramped shutdown. | Differential between oil and suction pressure falls below the cutout. Ignored for the first 60 s of run time; then linearly ramped from 0 barg to 2.09 barg in 5–10 min based on ambient temperature (>10°C: 5 min; >7.2°C: 6 min; >4.4°C: 7 min; >1.6°C: 8 min; >1.1°C: 9 min; ≤1.1°C: 10 min). A 30 s safety bypass below 50 Hz is employed during rampdown. | Auto-reset after the 120 s anti-recycle timer; locks out on the 3rd fault within 90 min — cycle the respective system switch OFF and ON to clear. | 195 |
| SYS X YYYYYYYY HIGH DISCHARGE TEMP | High Discharge Temperature Cutout; protects the motor and compressor from overheating; shuts down with a controlled ramped shutdown. | Discharge Temperature rises above 121°C. | System also inhibited from starting if the discharge temperature is above 93°C. Auto-reset after the 120 s anti-recycle timer; locks out on the 3rd fault within 90 min — cycle the respective system switch OFF and ON to clear. | 195 |
| SYS X YYYYYYYYYY LOW ECONOMIZER SUPERHEAT | Protects against excessive liquid refrigerant carryover from the economizer (possible EEV, sensor or other problems) and protects the system compressor from liquid refrigerant flood back from the economizer feed line if the economizer valve fails to close. | Superheat falls below 2.8°C for 5 min under either condition. Safety ignored for the first 10 min of operation if the system economizer feed valve is closed at 0%, and for 5 min of operation if the economizer feed valve is open greater than 0%. | Auto-reset after the 120 s anti-recycle timer; locks out on the 3rd fault within 90 min — cycle the respective system switch OFF and ON to clear. | 198 |
| SYS X YYYYYYYY SENSOR FAILURE: ZZZZZZZZZZZZ | Sensor Failure Cutout; prevents the system from running when a critical sensor, transducer, level sensor, or motor winding temperature sensor is not functioning properly and reading out of range. Checked at startup (prevents running) and faults/shuts down a system during operation if a safety threshold is exceeded or a sensor reads out of range high or low. | Failed sensor indicated by ZZZZZZZZZZZZ: SUCT PRESS, OIL PRESS, DSCH PRESS, ECONOMIZER PRESS, or MOTOR TEMP X. Start inhibit thresholds: suction, oil and discharge transducers 0.3–4.7 VDC; motor temperature sensor 0–116°C. | A specific motor temperature sensor can be ignored using the unit setup mode if it fails; report any failure to Johnson Controls service for investigation. Auto-reset after the 120 s anti-recycle timer; LOCKOUT after 3 faults — cycle the respective system switch OFF and ON to clear. | 197 |
| SYS X YYYYYYYY HIGH MOTOR TEMP | High Motor Temperature Cutout; prevents a compressor from running when its motor temperature is too high; system faults and shuts down. | Any compressor motor temperature sensor rises above 121°C. | System inhibited from starting if its motor temperature sensors indicate temperatures above 116°C. A sensor being ignored under the Unit Set-up Mode is not used when evaluating motor temperature. Auto-reset after the 120 s anti-recycle timer; locks out on the 3rd fault within 90 min — cycle the respective system switch OFF and ON to clear. | 197 |
| SYS X YYYYYYYY CONTROL VOLTAGE | System Control Voltage Cutout; alerts the operator that the 115 V AC control voltage to one of the systems is missing; affected system faults and shuts down immediately when the 115 V AC supply is lost. | 115 V AC supply lost to a single system — may be due to a system fuse that has been removed or is blown. Does not shut down a system if the UNIT switch is OFF (which electrically removes 115 V AC to all systems). | Will not cause a lockout; the system fault resets when power is returned. | 198 |
| Eductor clog fault | Safety sensing a loss of oil return to the compressor by monitoring the temperature of the line between the eductor and the suction line. No display message is documented for this safety. | Eductor line temperature is not less than the saturated suction temperature plus 5.5°C. Control looks at the eductor line temperature once a second; at start a clog timer is set at 600 s and is reset to 600 s each time the temperature is below the threshold. Eductor differential and eductor safety time are programmable under the PROGRAM key. | 198 | |
| SYS X YYYYYYYYYY ISO VALVE FAILED TO CLOSE | Isolation valve open warning; message displayed and fault code communicated. Shall not prevent the system from starting. | System isolation valve digital input J5-1 or J5-2 indicates the isolation valve did not close within 60 s of the evaporator heater outputs being turned on. | Warning clears when the unit begins precharge or the condition clears. | 198 |
| SYS X YYYYYYYYYY ISO VALVE FAILED TO OPEN | Isolation valve closed fault; system fault before compressor start. | Before starting the compressor, after the VSD has completely precharged, the system isolation valve digital input J5-1 or J5-2 indicates the system isolation valve did not open. | Causes a lockout on the first fault — manual reset required (cycle the respective system switch OFF and ON). | 198 |
| SYS X YYYYYYYYYY HIGH DSCH PRESSURE RATE | High Discharge Pressure Rate Cutout; immediate fault with no 3 s delay. | When enabled, during system run the discharge pressure of each running system is monitored once per second; system shuts down when its discharge pressure rate of change exceeds the programmed Discharge Pressure Rate Threshold (Unit Setup Mode). | Locks out on the first fault — manual reset required (cycle the respective system switch OFF and ON). | 198 |
| SYS X WARNING CONDENSER FAN VSD FAULT | System Condenser Fan VSD Fault Warning; auto reset warning monitoring the status of the fault input. | Fault input is low. | Auto reset — resets when the input is high. | 198 |
| SYS X WARNING REPLACE OIL FILTER | System Replace Oil Filter Warning; manual reset warning monitoring the status of the oil filter maintenance cycle. Can be enabled/disabled under Unit Setup Mode. | Differential Oil to Discharge Pressure is greater than 3.447 bar. | Manual reset warning. | 198 |
General status messages
| Code / display | Meaning | Cause | Action | Page |
|---|---|---|---|---|
| UNIT STATUS FLOW SWITCH SHUTDOWN | Flow switch is not allowing the chiller to run. Loss-of-flow protection against evaporator freeze-up; the manual lists flow switch operation among the unit auto-reset safeties. | Flow switch open (no chilled liquid flow). There is a 1 s delay on this safety to ensure the flow switch did not momentarily open. | Auto-reset: unit can run once the flow switch closes (chilled liquid flow re-established). | 200 |
| UNIT STATUS VSD COOLING SHUTDOWN | Chiller is shut down while all condenser fans, the VSD glycol pump, and the VSD fan run to bring the internal VSD ambient temperature down to an acceptable level before allowing the chiller to start. | Internal VSD ambient temperature above the acceptable level. | Chiller is allowed to start once the internal VSD ambient temperature is brought down to an acceptable level. | 200 |
Troubleshooting guide
| Code / display | Meaning | Cause | Action | Page |
|---|---|---|---|---|
| No display on control panel unit will not run | Control panel dead; unit will not run. | Supply to the panel is missing; line fuse is blown; chiller control board is defective; display board defective. | Verify that power is being applied to the unit from the customer supply; check 1FU, 2FU, 4FU, 5FU, 17FU, or 19FU; check 2T or 10T transformer; check fuses; replace chiller control board; replace display board. | 260 |
| Line fuse blows | Line fuse repeatedly blowing. | SCR diode module is defective; IBGT module is defective; VSD logic board is defective; SCR trigger board is defective. | Check SCR/Diode module; check IBGT module; replace VSD logic board; replace SCR trigger board. Always remove power to the chiller and ensure the DC Bus voltage has bled off. | 260 |
| Chiller fault: Low ambient temperature | Chiller shutdown on low ambient temperature. | Ambient temperature is lower than the programmed operating limit; ambient sensor is defective. | Check the programmed cutout and determine if it is programmed correctly; check the panel against the thermometer reading of ambient temperature. | 260 |
| Chiller fault: High ambient temperature | Chiller shutdown on high ambient temperature. | Ambient temperature is above the maximum operating limit; ambient sensor is defective. | Check outside air temperature; check the panel display against thermometer reading of ambient temperature at the sensor. | 260 |
| Chiller fault: Low leaving chilled liquid | Chiller shutdown on low leaving chilled liquid temperature. | Leaving chilled liquid temperature drops faster than the unit can unload (restricted flow; rapid flow changes; water loop too small; flow below minimum for chiller); chilled water sensor is defective. | Check for restricted flow; check for rapid flow changes; check water loop size; check flow against chiller minimum; check sensor against temp. gauge in water line; check sensor for intermittent operation; check wiring for shorts or opens. | 260 |
| System fault: Control voltage | 115 V AC control voltage missing to a system. | System fuse is blown. | Check respective system fuse 20FU or 21FU. Always remove power to the chiller and ensure the DC Bus voltage has bled off. | 260 |
| System fault: high discharge pressure | System shutdown on high discharge pressure. | Coils dirty; coils are damaged; fans not operating; system is overcharged. | Check and clean coils; comb out fins; check fan fuses, fan rotation, fan motor/blade; remove charge and check subcooling. | 261 |
| System fault: high discharge temperature | System shutdown on high discharge temperature. | Discharge Temperature Sensor is defective; condenser fans not operating or are running backwards; coils dirty; high superheat. | Check sensor; check fans; check and clean coils; measure superheat with gauges and thermocouple and determine cause. | 261 |
| System fault: high motor temperature | System shutdown on high motor temperature. | High motor temperature input from one of the sensors: refrigerant charge low; excess charge in system with high discharge pressure; high superheat (drain or feed valves not controlling); motor sensor reading incorrectly; economizer solenoid energized at low speeds with valve leaking through. | Check subcooling (charge low); check subcooling (excess charge); isolate cause (high superheat); program panel to ignore a single sensor; check economizer solenoid/valve leakage. | 261 |
| System fault: low suction pressure | System shutdown on low suction pressure. | Low charge; transducer reads incorrectly; suction temp. sensor reads incorrectly; low flow; condenser drain valve not operating; condenser or drain valve defective. | Check subcooling; check transducer against a gauge; check sensor against a thermocouple; check flow; check drain valve operation and check superheat. | 261 |
| System fault: low economizer superheat | System shutdown on low economizer superheat. | Economizer line temperature sensor is defective; economizer transducer is defective; economizer feed valve malfunction; economizer line solenoid purge valve malfunction. | Check temperature sensor; check transducer against a gauge; check economizer feed valve operation; check economizer line solenoid purge valve operation. | 261 |
| VSD fault: High baseplate temperature | VSD shutdown on high baseplate temperature. | Coolant level low; glycol pump is defective; VSD board is defective; IBGT module is defective; VSD cooling coil not clean. | Add coolant; replace glycol pump; replace VSD logic board; check defective IGBT module; clean VSD cooling coil. Always remove power to the chiller and ensure the DC Bus voltage has bled off. | 262 |
| VSD fault: Low DC Bus voltage | VSD shutdown on low DC Bus voltage. | SCR/Diode module is defective; SCR trigger board is defective. | Check SCR/diode module; check SCR trigger board. Always remove power to the chiller and ensure the DC Bus voltage has bled off. | 262 |
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