Inspection Procedure
WARNING: This page is about a different car, the 2003 Lexus LS 430. However, it is still accessible from the selected car via links, so may be relevant.
HINT:
In case of using the LEXUS hand-held tester, start the inspection step 1 and in case of not using the LEXUS hand-held tester, start form step 2.
- Check exhaust gas sensor using LEXUS hand-held tester.
PREPARATION:
Connect the LEXUS hand-held tester to the DLC3.
CHECK:
Check the exhaust gas sensor using DATA LIST.
- OK : Check and replace A/C ECU.
- NG : Go to next step.
- Check voltage between terminals NOx and SG-1 of A/C ECU connector.
PREPARATION:
Remove A/C ECU with connectors still connected.
CHECK:
- Turn ignition switch to ON.
- After continuing to turn ignition switch ON for more than 120 seconds, check voltage between terminals NOx and SG-1 of A/C ECU connector at the temperature.
OK:
Voltage:
1.0 - 4.5 V at 10 - 35°C (50 - 95 °F)
HINT:
When the sensor is exposed to the exhaust gas, the voltage goes down.
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- NG : Go to step 3.
- OK : Proceed to next circuit inspection shown on problem symptoms table (See PROBLEM SYMPTOMS TABLE ). However, if DTC B1461/61 is displayed, check and replace A/C ECU.
- Check exhaust gas sensor resistance.
PREPARATION:
Remove the exhaust gas sensor (See SMOG VENTILATION SENSOR ).
CHECK:
- Connect positive (+) lead from the battery to the terminal 3 and negative (-) lead to terminal 5.
- After keeping to apply battery positive voltage between terminals 3 and 5 for more than 120 seconds, measure resistance between terminals 1 and 4.
OK:
Resistance:
1 - 100 kΩ V at 10 - 35°C (50 - 95 °F)
HINT:
When the sensor is exposed to the exhaust gas, the resistance goes up.
- NG : Replace exhaust gas sensor.
- OK : Go to next step.
- Check harness and connector between A/C ECU and exhaust gas sensor (See HOW TO USE THE DIAGNOSTIC CHART AND INSPECTION PROCEDURE
).
- NG : Repair or replace harness for connector.
- OK : Check and replace A/C ECU.