Sleep therapy devices

Philips REMstar M: troubleshooting and error codes

The ServiceForge knowledge base holds 2 documented symptoms for the Philips REMstar M, with 2 ranked causes, 5 diagnostic checks with test points and expected values, and 129 error codes. Each symptom below shows its causes and the first check; the rest is one connection away. Connect ServiceForge to your AI

Symptoms

Calibration: Pressure sensor auto null

Automatic calibration of pressure sensor zero point when blower is off and flow sensor signal is stable

Ranked causes

1. Auto null calibration procedure required during operation (common)

First check

Verify blower is stopped and flow sensor signal is stable

Test point: Blower status, flow sensor output
Expected: Blower off, flow sensor signal stable
Tools: Visual inspection, oscilloscope

1 corrective action and part numbers are in ServiceForge. Connect ServiceForge to your AI

Calibration: Pressure sensor for snore detection

Calibrate pressure sensor amplifier and signal chain for snore detection; involves applying known pressures and verifying DC offset and frequency response

Ranked causes

1. Sensor calibration required at manufacture and after board installation (common)

First check

Verify sensor output voltage at calibrated pressures with 5.0V supply

Test point: Sensor output
Expected: 0.5V at -5 hPa (-5 cm H2O) and 4.5V at 40 hPa (40 cm H2O), Not specified
Tools: Voltmeter, pressure calibrator

3 more checks with pass and fail actions, 2 corrective actions, and part numbers are in ServiceForge. Connect ServiceForge to your AI

Error codes

Code	Meaning	Trigger	Severity
`001`	Failed destructive power on self test of external RAM address lines	Power-on self test execution	error
`002`	Failed destructive power on self test of external RAM data lines	Power-on self test execution	error
`003`	Failed non-destructive power on self test of internal RAM	Power-on self test execution	error
`004`	Failed non-destructive continuous self test of external RAM	Continuous self test during operation	error
`005`	ERR_RTC_DRIFT	Real-time clock time has drifted beyond acceptable tolerance	warning
`005`	RTC drift exceeds 4 seconds per minute	Continuous comparison between RTC and crystal oscillator	warning
`006`	Device improperly configured; pressure sensor required but absent	Device startup with sensor requirement mismatch	critical
`007`	Error in program flow	Program flow check failure	error
`008`	Non-volatile RAM storage unit corrupted upon power-up	Power-on NVRAM verification	error
`009`	ERR_FLOW_SENSOR_ABSENT	Flow sensor is not detected or not responding on sensor board	critical
`010`	Watchdog timeout after initialization completed	Watchdog timeout during normal operation	info
`011`	Watchdog timeout after initialization completed	Watchdog timeout during normal operation	error
`012`	Watchdog timeout before initialization completed	Watchdog timeout during startup sequence	error
`013`	Power on self test of watchdog timer failed; RAM flag test failed	Watchdog timer self test	error
`014`	Power on self test of watchdog timer failed	Watchdog timer self test	info
`015`	Power on self test of watchdog timer failed	Watchdog timer self test	error
`016`	DSP crystal fallen off board during operation	DSP clock monitoring	error
`017`	Therapy controller constant registers corrupted	Compiler optimization register verification	error
`018`	Stack memory overrun	Stack memory monitoring during operation	error
`019`	Therapy controller application software corrupted in Flash memory	Flash memory integrity check at startup	error
`019`	Device error after reflashing or Therapy PCA defect	Software reflash or hardware fault	error
`020`	Therapy controller vectored to undefined interrupt	Interrupt vector verification	error
`021`	Device attempting to access non-existent external RAM	External RAM access attempt	critical
`022`	PCA communication failure	Therapy PCA and Sensor PCA cannot communicate	error
`022`	ERR_SENSOR_TIMEOUT_RESET	Sensor board communication timeout; system performed reset	warning
`022`	100 ms without pressure/flow message from Sensor PCA	Message timeout during sensor polling	warning
`023`	100 ms without pressure/flow message after Sensor PCA reset	Persistent message timeout after reset attempt	error
`023`	ERR_SENSOR_TIMEOUT_REBOOT	Sensor board communication timeout; system rebooted	error
`023`	Sensor PCA or communication error	Sensor or PCA fault detected	error
`024`	ERR_SENSOR_STATUS_TIMEOUT_STOP	Sensor status response timeout; device stopped	critical
`024`	3 seconds without TOD message from Sensor PCA	TOD message timeout	critical
`025`	DSP watchdog timeout occurred	DSP watchdog monitoring	error
`026`	ERR_RTC_VALUE	Real-time clock value is invalid or out of range	error
`026`	Sensor PCA battery may be dead; RTC never set	Sensor power/RTC status check	info
`027`	ERR_RTC_CHECKSUM	Real-time clock checksum verification failed	error
`028`	ERR_FLOW_SENSOR_PWM_REBOOT	Flow sensor PWM signal invalid; system rebooted	error
`028`	Sensor PCA flow signal processing error during motor spinup	Motor spinup signal processing check	error
`029`	Motor rotor not spinning or wires broken during spinup	Motor spinup verification	error
`030`	ERR_SENSOR_RX_REBOOT	Sensor board receive data error; system rebooted	error
`030`	Sensor PCA >30 communication errors within last minute	Communication error rate monitoring	error
`031`	DSP application software corrupted in Flash memory	Flash memory integrity check	error
`031`	Device error after reflashing or Therapy PCA defect	Software reflash or hardware fault	error
`032`	Sensor PCA cannot keep up with communication message rate	Sensor message processing rate check	error
`032`	ERR_SENSOR_REQUEST_OVERRUN	Sensor request queue overflow; data lost	warning
`033`	Humidifier plate not making heat	Humidifier temperature monitoring	warning
`034`	Humidifier plate temperature at maximum (183°F)	Humidifier overheat protection	warning
`035`	Sensor PCA flow offset error; offset exceeded ±40 lpm for 5 min	Continuous flow offset monitoring	critical
`035`	ERR_FLOWOFFSET_STOP	Flow offset calibration out of range; device stopped	critical
`036`	DSP boot software corrupted in Flash memory	Flash boot code integrity check	error
`037`	ERR_PRESSUREOFFSET_STOP	Pressure offset calibration out of range; device stopped	critical
`037`	Sensor PCA pressure offset error; offset exceeded ±3 cm H2O for 5 min	Continuous pressure offset monitoring	critical
`038`	RAM copy of NVRAM storage unit corrupted	NVRAM consistency check during operation	critical
`039`	Invalid key depressed at startup or held >30 seconds post-startup	Key input monitoring at startup	info
`040`	Blower commanded on with corrupted Sensor PCA calibration table	Blower start with calibration check	critical
`040`	ERR_SENSOR_TABLE_CHECKSUM	Sensor calibration table checksum verification failed	error
`041`	Therapy controller 10 ms periodic loop exceeded 10 ms	Periodic task timing monitoring	info
`042`	Therapy controller 10 ms periodic loop exceeded 10 ms	Periodic task timing monitoring	error
`043`	Daily Values data corruption; both NV Images corrupted and defaulted	Daily averaging data integrity check	info
`043`	Therapy PCA error	Post-reflash fault or hardware defect	warning
`044`	DSP not responding to software version request at startup	DSP boot communication check	error
`045`	Therapy controller not getting responses from DSP	DSP communication monitoring	info
`046`	Therapy controller not getting responses from DSP	DSP communication monitoring during operation	error
`047`	Therapy processor cannot shut drive down via hardware; power-on self test	Motor shutdown verification during self test	error
`048`	DSP reported fault unable to be translated to error code	Therapy controller receives untranslatable fault from DSP	error
`049`	DSP not receiving messages from therapy controller	Communication loss between DSP and therapy controller	info
`050`	DSP not receiving messages from therapy controller	Persistent communication loss between DSP and therapy controller	error
`051`	DSP detected hardware trip line activation	Hardware trip line becomes active	error
`052`	V bus voltage dropped below minimum threshold	Supply voltage drops below 7.08 VDC for 25 ms	critical
`052`	Noisy or improper power supply	Electrical noise or improper power input detected	warning
`053`	Over-voltage condition	DC power supply voltage too high	error
`053`	V bus voltage exceeded maximum threshold	Supply voltage rises above 17.3 VDC for 25 ms	critical
`054`	Motor control failure	Motor cannot be controlled or is not spinning	error
`055`	DSP application data corrupted in Flash memory	Firmware detects data corruption during self-test	critical
`055`	Device error after reflashing or Therapy PCA defect	Software reflash or hardware fault	error
`056`	Motor speed detected as too high; control failure	Motor speed exceeds safe operating range	error
`057`	Motor speed detected as negative; control failure	Motor speed measurement indicates reverse rotation or negative value	error
`058`	Motor thermistor open circuit	Temperature sensor reads open or absent	warning
`059`	Motor thermistor shorted	Temperature sensor short circuit detected	warning
`060`	Program flow error; likely programming defect	DSP detects unexpected code execution path	error
`061`	Motor parameter measurement not found within timeout	Motor parameter measurement fails to complete in 18 seconds	error
`062`	ERR_RTC_STOPPED	Real-time clock stopped or not running	critical
`062`	Real-time clock not incrementing properly	RTC does not increment within one-minute period	info
`063`	Motor drive calibration data corrupted	Calibration data fails integrity check	error
`064`	Communications to humidifier lost	Humidifier link lost for 5 seconds after establishment	info
`065`	Humidifier thermistor may be shorted	Temperature sensor reads short circuit condition	info
`066`	Humidifier thermistor may be open	Temperature sensor reads open circuit condition	info
`067`	Humidifier reported untranslatable fault	Humidifier sends fault code that controller cannot interpret	info
`069`	DSP vectored to undefined interrupt	Processor executes undefined interrupt handler	error
`070`	ERR_SENSOR_BOARD_ABSENT	Sensor board is not detected at power-up	critical
`070`	Sensor PCA software version or serial number unreadable at startup	Sensor module fails to respond with version/serial at boot	error
`070`	Sensor or communication error	Sensor or PCA fault detected	error
`071`	Motor drive detected development boot code	Motor drive firmware is in development/debug mode	error
`072`	Therapy controller detected DSP running in boot mode	DSP does not transition from boot to application mode	critical
`073`	Program flow error; likely programming defect	DSP detects unexpected code execution path	info
`074`	Non-destructive power-on self-test of DSP RAM failed	RAM self-test fails during initialization	critical
`075`	Motor startup control failure	Attempts to start motor have failed	error
`076`	Motor acceleration control failure	Motor fails to accelerate after startup attempt	error
`077`	Motor deceleration control failure	Motor fails to decelerate properly	error
`078`	DSP 20 kHz periodic loop execution time exceeded	20 kHz loop execution exceeds 50 microseconds	error
`079`	DSP 100 Hz periodic loop execution time exceeded	100 Hz loop execution exceeds 10 milliseconds	error
`080`	DSP stack memory overrun	Stack pointer exceeds allocated memory bounds	critical
`081`	Sensor PCA communication handler exceeds message period	Sensor communication handler execution exceeds 5 ms	info
`081`	ERR_SENSOR_HANDLER_OVERRUN	Sensor interrupt handler queue overflowed	warning
`082`	Therapy Event Queue in Auto device is full	Queue buffer reaches maximum capacity	info
`083`	Therapy or DSP software does not support hardware version	Software compatibility check fails at startup	error
`084`	Event Type and length do not match	Event data structure validation fails	info
`085`	Pressure sensor missing or incompatible for Auto mode	Auto titration mode active without compatible digital pressure sensor	error
`086`	Debug-only log of missing digital pressure sensor	Debugging enabled and digital pressure sensor absent	info
`087`	Flow sensor tubing occluded with water	Constant near-zero flow output detected in Auto mode after blower off	critical
`087`	Flow sensor water damage or malfunction	Water damage detected or sensor fault after reflash	error
`088`	Flow sensor water damage or malfunction	Water damage detected or sensor fault after reflash	error
`088`	Flow sensor tubing may be occluded with water (log-only)	Constant near-zero flow output detected when not in Auto mode	info
`089`	Background thread task stuck preventing execution	One background task blocks others from running	error
`090`	Background thread task stuck (log-only)	One background task blocks others from running	info
`091`	Exception Stack end location memory overrun	Exception stack pointer exceeds upper memory bound	critical
`092`	Exception Stack has written into reserve area	Exception stack usage exceeds normal range	info
`093`	Exception Stack starting location memory overrun	Exception stack pointer exceeds lower memory bound	critical
`094`	FIQ Stack end location memory overrun	Fast Interrupt Queue stack exceeds upper bound	critical
`095`	FIQ Stack has written into reserve area	FIQ stack usage exceeds normal range	info
`096`	FIQ Stack starting location memory overrun	FIQ stack pointer exceeds lower memory bound	critical
`097`	IRQ Stack end location memory overrun	Interrupt Request stack exceeds upper bound	critical
`098`	IRQ Stack has written into reserve area	IRQ stack usage exceeds normal range	info
`099`	IRQ Stack starting location memory overrun	IRQ stack pointer exceeds lower memory bound	critical
`100`	Service Stack end location memory overrun	Service routine stack exceeds upper bound	critical
`101`	Service Stack has written into reserve area	Service stack usage exceeds normal range	info
`102`	Service Stack starting location memory overrun	Service stack pointer exceeds lower memory bound	critical
`103`	Data written to an illegal address	Memory write operation to invalid address detected	critical
`104`	Jump to an illegal address	Code execution jumps to invalid memory address	critical
`105`	Illegal instruction detected	Processor executes undefined or invalid instruction	critical

Likely causes and actions for each code are in ServiceForge. Connect ServiceForge to your AI

Community

0 fixes logged by technicians through their AI, with outcomes, for this model.

ServiceForge knowledge base record. Field-unverified unless technicians confirmed it. A teaching summary of the record, not a service manual. Export 2026-10-14.