B1461

AIR CONDITIONING: AIR CONDITIONING SYSTEM: B1461/61: Emission Gas NOx Sensor Circuit
B1461/61 - Emission Gas NOx Sensor Circuit

DESCRIPTION

The exhaust gas sensor detects NOx in the emission gas and transmits signals to the A/C amplifier. Based on the signals, the A/C amplifier automatically changes to FRESH, FRESH / RECIRCULATION, or RECIRCULATION.





WIRING DIAGRAM





INSPECTION PROCEDURE

PROCEDURE

1. INSPECT FUSE (LH-IG)

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

(b) Measure the resistance of the fuse.

Standard resistance:





NG -- CHECK FOR SHORT IN ALL HARNESSES AND COMPONENTS CONNECTED TO FUSE
OK -- Continue to next step.

2. READ VALUE USING TECHSTREAM

(a) Connect the Techstream to the DLC3.

(b) Turn the engine switch on (IG).

(c) Turn the Techstream on.

(d) Select the item below in the Data List, and read the display on the Techstream.

Data List / Air Conditioner:





OK:

The display is as specified in the normal condition.

Result:





C -- REPLACE AIR CONDITIONING AMPLIFIER

B -- PROCEED TO NEXT CIRCUIT INSPECTION SHOWN IN PROBLEM SYMPTOMS TABLE
A -- Continue to next step.

3. CHECK WIRE HARNESS (EXHAUST GAS SENSOR - BODY GROUND)





(a) Disconnect the B10 exhaust gas sensor connector.

(b) Measure the resistance of the wire harness side connector.

Standard resistance:





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

4. CHECK WIRE HARNESS (EXHAUST GAS SENSOR - BATTERY)





(a) Disconnect the B10 exhaust gas sensor connector.

(b) Measure the voltage of the wire harness side connector.

Standard voltage:





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

5. INSPECT EXHAUST GAS SENSOR





(a) Remove the exhaust gas sensor.

(b) After applying battery voltage between terminals 3 (IG) and 6 (E) for more than 120 seconds, measure the resistance between terminals 1 (SG) and 4 (DGS1).

(c) Measure the resistance of the sensor.

Standard resistance:





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

NG -- REPLACE EXHAUST GAS SENSOR
OK -- Continue to next step.

6. CHECK WIRE HARNESS (EXHAUST GAS SENSOR - A/C AMPLIFIER)





(a) Disconnect the B10 exhaust gas sensor connector.

(b) Disconnect the K52 A/C amplifier connector.

(c) Measure the resistance of the wire harness side connectors.

Standard resistance:





NG -- REPAIR OR REPLACE HARNESS AND CONNECTOR

OK -- REPLACE AIR CONDITIONING AMPLIFIER