AIR CONDITIONING SYSTEM, Diagnostic DTC:B1418/18

DTC Code DTC Name
B1418/18 Exhaust Gas Sensor Circuit

DESCRIPTION

The smog ventilation sensor is installed on the front of the cooler condenser assembly to control automatic air inlet. This sensor detects CO and HC in the emission gas and transmits signals to the air conditioning amplifier assembly.

DTC No.

Detection Item

DTC Detection Condition

Trouble Area

Memory

Note

B1418/18

Exhaust Gas Sensor Circuit

Open or short in smog ventilation sensor circuit (HC, CO)

  • Smog ventilation sensor

  • Harness or connector

  • Air conditioning amplifier assembly

-

-

WIRING DIAGRAM

E204869E03

CAUTION / NOTICE / HINT

Note:

Inspect the fuses for circuits related to this system before performing the following inspection procedure.

PROCEDURE

  1. READ VALUE USING INTELLIGENT TESTER (SMOG VENTILATION SENSOR)

    1. Use the Data List to check if the smog ventilation sensor is functioning properly

      Click here

      Body Electrical > Air Conditioner > Data List

      Tester Display

      Measurement Item

      Range

      Normal Condition

      Diagnostic Note

      Emission Gas Sensor

      Smog ventilation sensor (HC, CO)

      Min.: 0, Max.: 255

      Smog ventilation sensor (HC, CO) value increases as gas amount increases

      -

      OK

      The display is as specified in the normal condition column.

    Result

    Result

    Proceed to

    OK (When troubleshooting according to problem symptoms table)

    A

    OK (When troubleshooting according to the DTC)

    B

    NG

    C
    A

    PROCEED TO NEXT SUSPECTED AREA SHOWN IN PROBLEM SYMPTOMS TABLE

    Click here

    B

    REPLACE AIR CONDITIONING AMPLIFIER ASSEMBLY

    Click here

    C

  2. CHECK HARNESS AND CONNECTOR (SMOG VENTILATION SENSOR - BATTERY AND BODY GROUND)

    E204870C01

    *a

    Front view of wire harness connector

    (to Smog Ventilation Sensor)

    1. Disconnect the A47 sensor connector.

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

      Standard Voltage

      Tester Connection

      Switch Condition

      Specified Condition

      A47-3 (IG) - Body ground

      Engine switch on (IG)

      11 to 14 V

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

      Standard Resistance

      Tester Connection

      Condition

      Specified Condition

      A47-6 (E) - Body ground

      Always

      Below 1 Ω

    Result

    Result

    OK

    NG
    NG

    REPAIR OR REPLACE HARNESS OR CONNECTOR

    OK

  3. INSPECT SMOG VENTILATION SENSOR

    1. E204871E03

      Remove the smog ventilation sensor

      Click here

    2. Connect a battery positive (+) lead to terminal 3 (IG) and a negative (-) lead to terminal 6 (E).

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

      Standard Resistance

      Tester Connection

      Condition

      Specified Condition

      1 (SG) - 2 (DGS)

      Clean air at temperature of 20°C (68°F) and humidity of 60% blown on sensor

      10 to 40 kΩ
      Tip:

      When the sensor is exposed to the exhaust gas, the resistance increases.

    Result

    Result

    OK

    NG
    NG

    REPLACE SMOG VENTILATION SENSOR

    Click here

    OK

  4. CHECK HARNESS AND CONNECTOR (SMOG VENTILATION SENSOR - AIR CONDITIONING AMPLIFIER)

    1. Disconnect the G13 amplifier connector.

    2. Disconnect the A47 sensor connector.

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

      Standard Resistance

      Tester Connection

      Condition

      Specified Condition

      A47-1 (SG) - G13-13 (SG-2)

      Always

      Below 1 Ω

      A47-2 (DGS) - G13-6 (DGS)

      Always

      Below 1 Ω

      G13-13 (SG-2) - Body ground

      Always

      10 kΩ or higher

      G13-6 (DGS) - Body ground

      Always

      10 kΩ or higher

    Result

    Result

    OK

    NG
    OK

    REPLACE AIR CONDITIONING AMPLIFIER ASSEMBLY

    Click here

    NG

    REPAIR OR REPLACE HARNESS OR CONNECTOR