DTC B1418-11: Emission Gas Sensor (HC) Circuit Short to Ground [08/2023 - ]: Procedure

1. Read the Data List according to the display on the GTS.

   Body Electrical > Air Conditioner > Data List 

   Tester Display	Measurement Item	Range	Normal Condition	Diagnostic Note
   Emission Gas HC/CO Sensor	Displays the exhaust gas (CO, HC) detection status of the smog ventilation sensor	0 to 5 V	Decreases when the concentration of exhaust gas (CO, HC) around the smog ventilation sensor increases	Smog ventilation sensor circuit malfunction

   Body Electrical > Air Conditioner > Data List 

   Tester Display
   Emission Gas HC/CO Sensor

   OK

   The value of the Data List item decreases when the concentration of exhaust gas (CO, HC) increases.

   Result

   Proceed to
   OK
   NG

Result: 

OK 

REPLACE AIR CONDITIONING AMPLIFIER ASSEMBLY. Refer to  REMOVAL [10/2022 - ] 

Result: 

NG 

See step  2

Pre-procedure1

• Disconnect the A66 smog ventilation sensor connector.

• Measure the resistance according to the value(s) in the table below.

  Standard Resistance

  Tester Connection	Condition	Specified Condition	Result
  A66-5 (E) - Body ground	Always	Below 1 Ω	Ω

  Result

  Proceed to
  OK
  NG

Post-procedure1

• None

Result: 

NG 

REPAIR OR REPLACE HARNESS OR CONNECTOR 

Result: 

OK 

See step  3

Pre-procedure1

• Disconnect the A66 smog ventilation sensor connector.

• Measure the voltage according to the value(s) in the table below.

  Standard Voltage

  Tester Connection	Condition	Specified Condition	Result
  A66-1 (IG) - Body ground	Power switch on (IG)	11 to 14 V	V

  Result

  Proceed to
  OK
  NG

Post-procedure1

• None

Result: 

NG 

REPAIR OR REPLACE HARNESS OR CONNECTOR 

Result: 

OK 

See step  4

Pre-procedure1

• Disconnect the A66 smog ventilation sensor connector.
• Disconnect the C48 and C50 air conditioning amplifier assembly connector.

• Measure the resistance according to the value(s) in the table below.

  Standard Resistance

  Tester Connection	Condition	Specified Condition	Result
  A66-3 (DGS) - C50-9 (DGS)	Always	Below 1 Ω	Ω
  A66-4 (SG) - C48-14 (SG-2)	Always	Below 1 Ω	Ω
  A66-3 (DGS) or C50-9 (DGS) - Body ground	Always	10 kΩ or higher	kΩ
  A66-4 (SG) or C48-14 (SG-2) - Body ground	Always	10 kΩ or higher	kΩ

  Result

  Proceed to
  OK
  NG

Post-procedure1

• None

Result: 

NG 

REPAIR OR REPLACE HARNESS OR CONNECTOR 

Result: 

OK 

See step  5

Refer to INSPECTION [10/2022 - ]

Result

Result: 

OK 

REPLACE AIR CONDITIONING AMPLIFIER ASSEMBLY. Refer to  REMOVAL [10/2022 - ] 

Result: 

NG 

REPLACE SMOG VENTILATION SENSOR. Refer to  REMOVAL [10/2022 - ]