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Fail-Safe Table

When any of the following malfunctions (DTCs) is detected, fail-safe mode is activated.

However, when HVAC control module judges A/C system recovered, fail-safe mode is canceled.

FAIL SAFE DESCRIPTION CHART

DTC No. Trouble Area Fail-Safe Operation
When ignition switch is turned ON after malfunction is already detected When malfunction is detected during ignition switch is ON
B1502  Inside air temperature sensor circuit HVAC control module maintains last normal value. HVAC control module controls actuators assuming that inside air temperature is 25 °C (77 °F).
B1503  A/C evaporator temperature sensor circuit HVAC control module assuming that evaporator temperature is 0 °C (32 °F).
  • HVAC control module turns off A/C switch signal.
  • HVAC control module controls actuators assuming that evaporator temperature is 0 °C (32 °F).
B1504  Sunload sensor circuit HVAC control module maintains last normal value. HVAC control module controls actuators assuming that amount of sunlight is 0 W/m2 .
B1551  Serial communication circuit
  • HVAC control module maintains last normal value of outside air temperature.

    4 seconds after, HVAC control module assuming that outside air temperature is 20 °C (68 °F).

  • HVAC control module maintains last normal value of engine coolant temperature.

    4 seconds after, HVAC control module assuming that engine coolant temperature is 80 °C (176 °F).

  • HVAC control module controls actuators assuming that vehicle speed is 40 km/h (25 mph).
  • HVAC control module controls actuators assuming that engine type signal is J20.
  • HVAC control module controls actuators assuming that combination meter spec signal is US.
 HVAC control module controls actuators assuming that outside air temperature is 20 °C (68 °F), engine coolant temperature is 80 °C (176 °F), vehicle speed is 40 km/h (25 mph), engine type signal is J20 and combination meter spec signal is US.
B1552  HVAC control module check sum error
B1553  CAN communication circuit
B1557  VSS signal failure HVAC control module controls actuators assuming that vehicle speed is 40 km/h (25 mph).
B1561  ECT signal failure HVAC control module maintains last normal value of engine coolant temperature. 4 seconds after, HVAC control module assuming that engine coolant temperature is 80 °C (176 °F). HVAC control module controls actuators assuming that engine coolant temperature is 80 °C (176 °F).
B1562  Outside air temperature signal failure HVAC control module maintains last normal value of outside air temperature.
4 seconds after, HVAC control module assuming that outside air temperature is 20 °C (68 °F).		 HVAC control module controls actuators assuming that outside air temperature is 20 °C (68 °F).
B1570  Engine type signal failure HVAC control module controls actuators assuming that engine type signal is J20.
B1571  Combination meter spec signal failure HVAC control module controls actuators assuming that combination meter spec signal is US.
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