Lexus ES: Fail-safe Chart
FAIL-SAFE CHART
DIAGNOSIS FUNCTION
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Heated steering wheel controller (steering vibration ECU) has diagnosis function.
Condition
Detection Condition
Response when malfunction detected
Recovery Conditions
ECU malfunction
Internal malfunction detected in the heated steering wheel controller (steering vibration ECU)
ECU reset
Malfunctions cleared during reset
Thermistor malfunction
When an open circuit or short occurs in the thermistor inside the steering wheel assembly for 2 seconds or more
Heater output off
Normal condition of the thermistor is restored
Heater OFF request signal received
Heater malfunction
Overcurrent protection or overheating protection operates
Heater output off
Heater OFF request signal received
Lost communication
Lost communication with air conditioning amplifier assembly continuously for 15 seconds
Heater output off
Normal communication continues for 10 seconds
FAIL-SAFE FUNCTION
| Content | Operation | |
|---|---|---|
| ECU malfunction | Internal malfunction detected in the heated steering wheel controller (steering vibration ECU) | ECU reset |
| Heater malfunction | Drive element overcurrent detection | Heater output off |
| Drive element overheat detection | Heater output off | |
| Power source malfunction | Low-voltage detection | Heater output off |
| Overvoltage detection | Heater output off | |
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Data List / Active Test
DATA LIST / ACTIVE TEST DATA LIST NOTICE: In the table below, the values listed under "Normal Condition" are reference values. Do not depend solely on these reference values when deciding whether a pa
Diagnostic Trouble Code Chart
DIAGNOSTIC TROUBLE CODE CHART HEATED STEERING WHEEL SYSTEM DTC No. Detection Item Link B14B7 Lost Communication with Steering Heater ECU
Lost Communication with Steering Heater ECU (B14B7)
DESCRIPTION The heated steering wheel controller (steering vibration ECU) communicates with the air conditioning amplifier assembly via LIN communication. B14B7 is output when a communication malfunct
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On-vehicle Inspection
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DC/DC Converter Temperature Sensor "A" Circuit Voltage Out of Range (P0C381C)
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Inverter with converter assembly internal circuit malfunction
Hybrid cooling
