WTT Fault Codes

These are the fault codes reported by Webasto Thermo Test.

Depending on the version, the fault code may be reported in this format: 3Ah (i.e. ending in an 'h' instead of starting '0x'. To convert to the format given here, remove the 'h' and add '0x' at the start - so 3Ah is equivalent to 0x3A on this list.

List kindly supplied by alex_pescaru.

Code (Hex)	Description
0x01	Defective control unit
0x02	No start
0x03	Flame failure
0x04	Supply voltage too high
0x05	Flame was detected prior to combustion
0x06	Heating unit overheated
0x07	Heating unit interlocked
0x08	Metering pump short circuit
0x09	Combustion air fan short circuit
0x0A	Glow plug/flame monitor short circuit
0x0B	Circulation pump short circuit
0x0C	No communication to air condition
0x0D	Green LED short circuit
0x0E	Yellow LED short circuit
0x0F	No configuration signal
0x10	Solenoid valve short circuit
0x11	ECU wrong coded
0x12	W-Bus communication failure
0x13	Vehicle fan relay short circuit
0x14	Temperature sensor short circuit
0x15	Combustion air fan blocked
0x16	Battery main switch short circuit
0x17	Invalid air flow reduction
0x19	Glow plug/electronic ignition short circuit
0x1A	Flame sensor short circuit
0x1B	Overheat short circuit
0x1D	Solenoid valve shed test short circuit
0x1E	Fuel sensor short circuit
0x1F	Nozzle stock heating short circuit
0x20	Operation indicator short circuit
0x21	Flame indicator short circuit
0x22	Reference resistance wrong
0x23	Crash interlock activated
0x24	Car is almost out of fuel
0x25	Fuel pre heating short circuit
0x26	PCB temperature sensor short circuit
0x27	Ground contact to the ECU broken
0x28	Board net energy manager low power voltage
0x29	Fuel priming still not done
0x2A	Error in the radio telegram
0x2B	Telestart still not programmed
0x2C	The pressure sensor has short circuit
0x32	No start from control idle period
0x33	Flame monitor signal invalid
0x34	Default values entered
0x35	EOL programming has not been carried out
0x36	Thermal fuse short circuit
0x45	Error relay box (short circuit/open circuit of heating relay)
0x50	User interface idle-Mode (no-communication)
0x51	User interface has communication fault
0x52	User interface send no defined operating mode
0x53	Heater fan status message negative
0x54	Heater fan status bus has short circuit to UB
0x55	Temperature water sensor failure
0x56	Temperature water sensor short circuit to UB
0x57	Overheating water temperature sensor
0x58	Overstepping water temperature sensor gradient
0x59	Overheating blow temperature sensor
0x5A	Overstepping low temperature sensor gradient
0x5B	Overheating printed circuit board temperature sensor
0x5C	Overstepping printed circuit board temp sensor gradient
0x5D	Cabin temperature sensor failure
0x5E	Flame detector gradient failure
0x5F	Emergency cooling
0x81	EOL checksum error
0x82	No start during test-run
0x83	Flame failure
0x84	Operating voltage too low
0x85	Flame was detected after combustion
0x87	Heater lock-out permanent
0x88	Fuel pump failure
0x89	Combustion air fan interruption
0x8A	Glow plug / flame monitor interruption
0x8B	Circulation pump interruption
0x8D	Green LED interruption
0x8E	Yellow LED interruption
0x90	Solenoid valve interruption
0x91	Control unit locked or coded as neutral
0x92	Command refresh failure
0x94	Temperature sensor interruption
0x95	Combustion air fan tight
0x97	Overheat sensor position wrong
0x98	Fault 152 (Power supply interruption)
0x99	Glow plug / electronic ignition unit interruption
0x9A	Flame sensor interruption
0x9B	Setpoint transmitter invalid
0x9C	Intelligent undervoltage detection
0x9D	Solenoid valve shed test interruption
0x9E	Fuel sensor interruption
0x9F	Nozzle stock heating interruption
0xA0	Operating indicator interruption
0xA1	Flame indicator interruption
0xA5	Fuel pre heating interruption
0xA6	PCB temperature sensor interruption
0xA8	Communication board net energy manager error
0xAA	Send on W-Bus not succeed
0xAB	Overheat sensor interruption
0xAC	The pressure sensor failure
0xB6	Thermal fuse interrupted
0xFF	Unknown error code

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