DTC 18

HEATING / AIR CONDITIONING: AIR CONDITIONING SYSTEM: B1418/18: Exhaust Gas Sensor Circuit
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.

WIRING DIAGRAM

INSPECTION PROCEDURE

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

PROCEDURE

1. READ VALUE USING TECHSTREAM (SMOG VENTILATION SENSOR)

(a) Use the Data List to check if the smog ventilation sensor is functioning properly Scan Tool Testing and Procedures.

Air Conditioner

OK:

The display is as specified in the normal condition column.

Result

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

B -- REPLACE AIR CONDITIONING AMPLIFIER ASSEMBLY Removal

A -- PROCEED TO NEXT SUSPECTED AREA SHOWN IN PROBLEM SYMPTOMS TABLE Symptom Related Diagnostic Procedures

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

(a) Disconnect the A47 sensor connector.

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

Standard Voltage:

Text in Illustration

NG -- REPAIR OR REPLACE HARNESS OR CONNECTOR
OK -- Continue to next step.

3. INSPECT SMOG VENTILATION SENSOR

(a) Remove the smog ventilation sensor Removal.

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

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

Standard Resistance:

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

NG -- REPLACE SMOG VENTILATION SENSOR Removal
OK -- Continue to next step.

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

(a) Disconnect the G13 amplifier connector.

(b) Disconnect the A47 sensor connector.

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

Standard Resistance:

NG -- REPAIR OR REPLACE HARNESS OR CONNECTOR

OK -- REPLACE AIR CONDITIONING AMPLIFIER ASSEMBLY Removal