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Diagnostic Trouble Code Chart

WARNING: This page is about a different car, the 2003 Lexus IS 300. However, it is still accessible from the selected car via links, so may be relevant.

If malfunction code is displayed during the DTC check, check the circuit listed for that code in the table below (Proceed to the page given for that circuit.)

DIAGNOSTIC TROUBLE CODE REFERENCE

DTC No. (See page) Detection Item Trouble Area Memory
B1400 Normal - -
DTC B1411 Room Temperature Sensor Circuit  Room temperature sensor circuit
  • Room temp. sensor
  • Harness or connector between room temp. sensor and A/C amplifier
  • A/C amplifier
 (5)
DTC B1412 Ambient Temperature Sensor Circuit  Ambient temperature sensor circuit
  • Ambient temp. sensor
  • Harness or connector between ambient temp. sensor and ECM
  • Harness or connector between ECM and A/C amplifier
  • A/C amplifier
 (5)
DTC B1413 Evaporator Temperature Sensor circuit  Evaporator temperature sensor circuit
  • Evaporator temp. sensor
  • Harness or connector between evaporator temp. sensor and A/C amplifier
  • A/C amplifier
 (5)
DTC B1421 Solar Sensor Circuit (3) Solar sensor circuit
  • Solar sensor
  • Harness or connector between solar sensor and A/C amplifier
  • A/C amplifier
 -
(5)
DTC B1422 Compressor Lock Sensor Circuit (4) All conditions below are detected for 3 sec. or more
  1. Engine speed: 450 rpm or more
  2. Ratio between engine and compressor rpm deviates 20% or more in comparison to normal operation.
  • Compressor drive belt
  • Compressor lock sensor
  • Compressor
  • Harness and connector between A/C amplifier and compressor, compressor lock sensor
  • A/C amplifier
 -
DTC B1423 Pressure Switch Circuit  Open in pressure sensor circuit Abnormal refrigerant pressure [below 196 kPa (2.0 kgf/cm2 , 28 psi) over 3,140 kPa (32.0 kgf/cm2 , 455 psi)]
  • Pressure switch
  • Harness or connector between pressure switch and ECM.
  • Harness or connector between ECM and A/C amplifier
  • Refrigerant pipe line
  • A/C amplifier
  • Compressor
 -
DTC B1431 Air Mix Damper Position Sensor Circuit  Air mix damper position sensor circuit
  • Air mix damper position sensor
  • A/C amplifier
  • Harness or connector between air mix damper position sensor and A/C amplifier
 -
DTC B1432 Air Inlet Damper Position Sensor Circuit  Air inlet damper position sensor circuit
  • Air inlet damper position sensor circuit
  • A/C amplifier
  • Harness or connector between air inlet damper position sensor and A/C amplifier
 (5)
DTC B1433 Air Outlet Damper Position Sensor Circuit  Air outlet damper position sensor circuit
  • Air outlet damper position sensor circuit
  • A/C amplifier
  • Harness or connector between air outlet damper position sensor and A/C amplifier
 (5)
DTC B1441 Air Mix Damper Control Servomotor Circuit  Air mix damper control servomotor circuit
  • Air mix damper control servomotor
  • Air mix damper position sensor
  • Harness and connector between A/C amplifier and air mix position sensor
  • Harness and connector between A/C amplifier and mix damper control servomotor
  • A/C amplifier
 (5)
DTC B1442 Air Inlet Damper Control Servomotor Circuit  Air inlet damper control servomotor
  • Air inlet damper control servomotor
  • Air inlet damper position sensor
  • Harness and connector between A/C amplifier and air inlet position sensor
  • Harness and connector between A/C amplifier and inlet damper control servomotor
  • A/C amplifier
 (5)
DTC B1443 Air Outlet Damper Control Servomotor Circuit  Air outlet damper control servomotor circuit
  • Air outlet damper control servomotor
  • Air outlet damper position sensor
  • Harness and connector between A/C amplifier and air outlet position sensor
  • Harness and connector between A/C amplifier and outlet damper control servomotor
  • A/C amplifier
 (5)
99 Multiprex communication circuit Open in multiprex communication circuit -
(1) If the room temp. is approx. -20°C (-4°F) or lower, DTC B1411 may be output even though the system is normal.
(2) If the ambient temperature is approx. -50°C (-58°F) or lower, a DTC may be output even though the system is normal.
(3) If the check is being performed in a dark place, DTC B1421 (solar sensor circuit abnormal) could be displayed. In this case, perform DTC check again while shining a light, such as an inspection light, on the solar sensor. If DTC B1421 is still displayed, there could be trouble in the solar sensor circuit.
(4) Compressor lock (DTC B1422) is indicated only for a current malfunction (See DTC B1422 COMPRESSOR LOCK SENSOR CIRCUIT ). To confirm DTC B1422, preform the following steps.
  1. With the engine ON, enter the DTC check mode.
(5) 15 seconds or more
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