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.

Check voltage between terminal SMOKE of luggage room J/B ECU connector and body ground.
PREPARATION:

Remove luggage room J/B ECU with connectors still connected.

CHECK:
1. Turn ignition switch to ON.
2. Operate rear A/C control panel AUTO mode.
3. By using cigarette smoke, measure voltage between terminals SMOKE of luggage room J/B ECU and body ground.
OK:

Voltage: Above 4.0 V

Fig 1: Identifying Terminal Smoke Of Luggage Room J/B ECU Connector And Body Ground
Courtesy of © TOYOTA, LICENSE AGREEMENT TMS1002
1. OK : Go to step 4 .
2. NG : Go to next step.
Check smoke sensor.
PREPARATION:

Remove the smoke sensor (See REAR COOLING UNIT ).

CHECK:
1. Connect the positive (+) lead from the battery to terminal 1 and negative (-) lead to terminal 3.
2. By using cigarette smoke, measure the voltage as connector terminal 2 and 3.
OK:

There is no smoke: Below 1.0 V

There is smoke: Above 4.0 V

NOTE: Since the sensor detects smoke with light, check the sensor in dark state.

Fig 2: Checking Smoke Sensor
Courtesy of © TOYOTA, LICENSE AGREEMENT TMS1002
1. NG : Replace smoke sensor.
2. OK : Go to next step.
Check harness and connector between smoke sensor and Rr-J/B ECU (See HOW TO USE THE DIAGNOSTIC CHART AND INSPECTION PROCEDURE ).
1. NG : Repair or replace harness or connector.
2. OK : Go to next step.
Check harness and connector between smoke sensor and A/C amplifier, smoke sensor and body ground (See HOW TO USE THE DIAGNOSTIC CHART AND INSPECTION PROCEDURE ).
1. NG : Repair or replace harness or connector.
2. OK : Check and replace Rr-J/B ECU.