AIR CONDITIONING SYSTEM, Diagnostic DTC:B1418/18

DESCRIPTION

The smog ventilation sensor is installed on the front of the cooler condenser assembly to automatically control the air inlet mode (FRESH, FRESH/RECIRCULATION or RECIRCULATION).

This sensor detects CO and HC in exhaust gasses and transmits signals to the air conditioning amplifier assembly.

WIRING DIAGRAM

INSPECTION PROCEDURE

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

• If DTCs B1418/18 and B1461/61 are stored simultaneously, there may be a malfunction in the smog ventilation sensor power source related circuits.

PROCEDURE

1. READ VALUE USING GTS

   
   

   1. Connect the GTS to the DLC3.

   2. Turn the engine switch on (IG).

   3. Turn the GTS on.

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

   5. Enter the following menus: Body Electrical / Air Conditioner / Data List.

   6. Check the value(s) by referring to the table below.

      Air Conditioner

      Tester Display	Measurement Item/Range	Normal Condition	Diagnostic Note
      Emission Gas Sensor	Emission gas (HC, CO) / 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 Problem Symptoms Table) B OK (When troubleshooting according to the DTC) C

   
   

   B

   PROCEED TO NEXT SUSPECTED AREA SHOWN IN PROBLEM SYMPTOMS TABLE Click here

   C

   REPLACE AIR CONDITIONING AMPLIFIER ASSEMBLY Click here

   A

2. CHECK HARNESS AND CONNECTOR (SMOG VENTILATION SENSOR - IG POWER SOURCE AND BODY GROUND)

   
   

   1. Disconnect the A6 smog ventilation sensor connector.

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

      Standard Voltage
      Tester Connection Condition Specified Condition A6-3 (IG) - Body ground Engine switch on (IG) 11 to 14 V A6-3 (IG) - Body ground Engine switch off Below 1 V

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

      Standard Resistance
      Tester Connection Condition Specified Condition A6-6 (E) - Body ground Always Below 1 Ω

   
   

   NG

   REPAIR OR REPLACE HARNESS OR CONNECTOR

   OK

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

   
   

   1. Disconnect the H54 and H55 air conditioning amplifier assembly connectors.

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

      Standard Resistance
      Tester Connection Condition Specified Condition A6-1 (SG) - H54-13 (SG-2) Always Below 1 Ω A6-2 (DGS) - H55-3 (DGS) Always Below 1 Ω H54-13 (SG-2) - Body ground Always 10 kΩ or higher H55-3 (DGS) - Body ground Always 10 kΩ or higher

   
   

   NG

   REPAIR OR REPLACE HARNESS OR CONNECTOR

   OK

4. INSPECT SMOG VENTILATION SENSOR

   
   
   1. 

      Text in Illustration

      *a	Component without harness connected (Smog Ventilation Sensor)

      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. 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 of the sensor before being exposed to exhaust gas is 10 kΩ to 40 kΩ.

   
   

   NG

   REPLACE SMOG VENTILATION SENSOR Click here

   OK

   REPLACE AIR CONDITIONING AMPLIFIER ASSEMBLY Click here