DESCRIPTION
WIRING DIAGRAM
INSPECTION PROCEDURE
INSPECT FUSE (LH-IG)
READ VALUE OF INTELLIGENT TESTER
CHECK WIRE HARNESS (SMOG VENTILATION SENSOR - BODY GROUND)
CHECK WIRE HARNESS (SMOG VENTILATION SENSOR - BATTERY)
INSPECT SMOG VENTILATION SENSOR
CHECK WIRE HARNESS (SMOG VENTILATION SENSOR - A/C AMPLIFIER)
DTC B1461/61 Emission Gas NOx Sensor Circuit
DESCRIPTION
The smog ventilation sensor detects NOx in the emission gas and transmits signals to the A/C amplifier. Based on the signals, the A/C amplifier performs automatic air inlet control (FRESH, FRESH / RECIRCULATION, or RECIRCULATION mode).
| DTC No. | DTC Detection Condition | Trouble Area |
| B1461/61 |
Open or short in emission gas NOx sensor circuit |
Smog ventilation sensor (emission gas NOx sensor)
Harness and connector between smog ventilation sensor (emission gas NOx sensor) and A/C amplifier
A/C amplifier
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WIRING DIAGRAM
INSPECTION PROCEDURE
Remove the LH-IG fuse from the cowl side junction block LH.
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 |
| 2.READ VALUE OF INTELLIGENT TESTER |
Connect the intelligent tester to the DLC3.
Turn the engine switch on (IG) and turn the intelligent tester main switch on.
Allow exhaust gas (NOx) to travel to the sensing portion of the smog ventilation sensor.
Select the item below in the Data List, and read the display on the intelligent tester.
Data List / Air Conditioner:| Item | Measure Item / Display (Range) | Normal Condition | Diagnostic Note |
Emission Gas Sensor
(Emiss Gas Sens) | Emission gas NOx sensor / 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 |
| | PROCEED TO NEXT CIRCUIT INSPECTION SHOWN IN PROBLEM SYMPTOMS TABLE |
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| | REPLACE AIR CONDITIONING AMPLIFIER |
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| 3.CHECK WIRE HARNESS (SMOG VENTILATION SENSOR - BODY GROUND) |
Disconnect the smog ventilation sensor connector.
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 |
| | REPAIR OR REPLACE HARNESS OR CONNECTOR |
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| 4.CHECK WIRE HARNESS (SMOG VENTILATION SENSOR - BATTERY) |
Disconnect the smog ventilation sensor connector.
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) | 10 to 14 V |
| Engine switch off | Below 1 V |
| | REPAIR OR REPLACE HARNESS OR CONNECTOR |
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| 5.INSPECT SMOG VENTILATION SENSOR |
Remove the smog ventilation sensor.
Apply battery voltage between terminals 3 (IG) and 6 (E).
Allow exhaust gas (NOx) to travel to the sensing portion of the smog ventilation sensor, and measure the resistance between terminals 1 (SG) and 4 (DGS1).
- OK:
- When the sensor is exposed to the exhaust gas, the resistance increases.
- The resistance before blowing exhaust gas is 10 kΩ to 40 kΩ.
| | REPLACE SMOG VENTILATION SENSOR |
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| 6.CHECK WIRE HARNESS (SMOG VENTILATION SENSOR - A/C AMPLIFIER) |
Disconnect the exhaust gas sensor connector.
Disconnect the A/C amplifier connector.
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 |
| B11-4 (DGS1) - J58-33 (DGS1) | Always | Below 1 Ω |
| J58-39 (SG-6) - Body ground | Always | 10 kΩ or higher |
| J58-33 (DGS1) - Body ground | Always | 10 kΩ or higher |
| | REPAIR OR REPLACE HARNESS OR CONNECTOR |
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| OK | |
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| REPLACE AIR CONDITIONING AMPLIFIER |
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LEXUS IS250, IS220d / GSE20 ALE20
