AIR CONDITIONING SYSTEM, Diagnostic DTC:B1418/18

DTC Code DTC Name
B1418/18 Exhaust Gas Sensor Circuit

DESCRIPTION

The smog ventilation sensor, which is installed on the front of the condenser, is used for automatic air inlet control. This sensor detects CO and HC in the emission gas and transmits signals to the A/C amplifier.

DTC No. DTC Detection Condition Trouble Area
B1418/18 Open or short in smog ventilation sensor circuit (HC, CO)
  • Smog ventilation sensor (emission gas sensor)

  • Harness or connector between smog ventilation sensor (emission gas sensor) and A/C amplifier

  • A/C amplifier

WIRING DIAGRAM

A015ZQIE01

INSPECTION PROCEDURE

PROCEDURE


  1. INSPECT FUSE (LH-IG)


    1. A01621EE11

      Remove the LH-IG fuse from the cowl side junction block LH.

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

      Standard Resistance
      Tester Item Condition Specified Condition
      LH-IG fuse Always Below 1 Ω

    NG
    OK
  2. READ VALUE USING INTELLIGENT TESTER


    1. Connect the intelligent tester to the DLC3.

    2. Turn the engine switch on (IG).

    3. Turn the intelligent tester on.

    4. Allow exhaust gas (HC, CO) to travel to the sensing portion of the smog ventilation sensor.

    5. Select the item below in the Data List, and read the display on the intelligent tester.

      Data List / Air Conditioner
      Tester Display Measurement Item/Range Normal Condition Diagnostic Note

      Emission Gas Sensor

      (Emiss Gas Sens)

      Emission gas / Min.: 0, Max.: 255 Smog ventilation sensor value increases as gas amount increases -
      OK
      The display is as specified in the normal condition column.
      Result
      Result Proceed to
      NG A
      OK (When troubleshooting according to the Problem Symptoms Table) B
      OK (When troubleshooting according to the DTC) C

    B
    C
    A
  3. CHECK HARNESS AND CONNECTOR (SMOG VENTILATION SENSOR - BODY GROUND)


    1. A015YHDE01

      Disconnect the smog ventilation sensor connector.

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

      Standard Resistance
      Tester Connection Condition Specified Condition
      B11-6 (E) - Body ground Always Below 1 Ω

    NG
    OK
  4. CHECK HARNESS AND CONNECTOR (SMOG VENTILATION SENSOR - BATTERY)


    1. A015YHDE02

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

      Standard Voltage
      Tester Connection Condition Specified Condition
      B11-3 (IG) - Body ground Engine switch on (IG) 11 to 14 V
      Engine switch off Below 1 V

    NG
    OK
  5. INSPECT SMOG VENTILATION SENSOR


    1. A015ZYUE01

      Remove the smog ventilation sensor.

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

    3. Allow exhaust gas (HC, CO) to travel to the sensing portion of the smog ventilation sensor, and measure the resistance between terminals 1 (SG) and 2 (DGS).

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

      Tech Tips

      The resistance before blowing exhaust gas is 10 kΩ to 40 kΩ.


    NG
    OK
  6. CHECK HARNESS AND CONNECTOR (SMOG VENTILATION SENSOR - A/C AMPLIFIER)


    1. A0162IGE03

      Disconnect the A/C amplifier connector.

    2. A015YHDE03

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

      Standard Resistance
      Tester Connection Condition Specified Condition
      B11-1 (SG) - J58-39 (SG-6) Always Below 1 Ω
      B11-2 (DGS) - J58-34 (DGS) Always Below 1 Ω
      J58-39 (SG-6) - Body ground Always 10 kΩ or higher
      J58-34 (DGS) - Body ground Always 10 kΩ or higher

    NG
    OK