- Rear room temperature sensor RH
- Harness or connector between rear room temperature sensor RH and air conditioning amplifier assembly
- Air conditioning amplifier assembly
| Last Modified: 11-27-2007 | 1.6 C | |
| Service Category: Vehicle Interior | Section: Heating/Air Conditioning | |
| Model Year: 2008 | Model: LX570 | Doc ID: RM000002SLV009X |
| Title: HEATING / AIR CONDITIONING: AIR CONDITIONING SYSTEM: DESCRIPTION (2008 LX570) | ||
|
DTC |
B1468/68 |
Rear Passenger Side Room Temperature Sensor Circuit |
DESCRIPTION
The rear room temperature sensor RH is installed in the rear quarter trim board RH to detect the rear room temperature and control the heater and air conditioner auto mode. The resistance of the rear room temperature sensor RH changes in accordance with the rear room temperature for RH seat. As the temperature decreases, the resistance increases. As the temperature increases, the resistance decreases.
The air conditioning amplifier assembly applies a voltage (5 V) to the rear room temperature sensor RH and reads voltage changes as changes in the resistance of the rear room temperature sensor RH.
|
DTC Code |
DTC Detection Condition |
Trouble Area |
|---|---|---|
|
B1468/68 |
An open or short in the rear room temperature sensor RH circuit. |
|
WIRING DIAGRAM
INSPECTION PROCEDURE
PROCEDURE
|
1. |
READ VALUE USING TECHSTREAM (REAR ROOM TEMPERATURE SENSOR RH) |
(a) Use the Data List to check if the rear room temperature sensor RH is functioning properly.
Air Conditioner
|
Tester Display |
Measurement Item/Range |
Normal Condition |
Diagnostic Note |
|---|---|---|---|
|
Room Temperature Sensor (RP) |
Rear room temperature sensor RH / Min.: -6.5°C (20.3°F) Max.: 57.25°C (135.05°F) |
Actual rear room temperature for RH seat displayed |
Open in the circuit: -19°C (-2.2°F). Short in the circuit: 70°C (158°F). |
OK:
The display is as specified in the normal condition.
|
|
2. |
INSPECT REAR ROOM TEMPERATURE SENSOR RH |
(a) Remove the rear room temperature sensor RH
.
(b) Measure the resistance according to the value(s) in the table below.
Standard Resistance:
|
Tester Connection |
Condition |
Specified Condition |
|---|---|---|
|
1 (+) - 2 (-) |
10°C (50°F) |
3.00 to 3.73 kΩ |
|
15°C (59°F) |
2.45 to 2.88 kΩ |
|
|
20°C (68°F) |
1.95 to 2.30 kΩ |
|
|
25°C (77°F) |
1.60 to 1.80 kΩ |
|
|
30°C (86°F) |
1.28 to 1.47 kΩ |
|
|
35°C (95°F) |
1.00 to 1.22 kΩ |
|
|
40°C (104°F) |
0.80 to 1.00 kΩ |
|
|
45°C (113°F) |
0.65 to 0.85 kΩ |
|
|
50°C (122°F) |
0.50 to 0.70 kΩ |
|
|
55°C (131°F) |
0.44 to 0.60 kΩ |
|
|
60°C (140°F) |
0.36 to 0.50 kΩ |
NOTICE:
Even slightly touching the sensor may change the resistance value. Be sure to hold the connector of the sensor.
HINT:
As the temperature increases, the resistance decreases (See the graph).
|
|
3. |
CHECK HARNESS AND CONNECTOR (REAR ROOM TEMPERATURE SENSOR RH - AIR CONDITIONING AMPLIFIER) |
(a) Disconnect the z37 sensor connector.
(b) Disconnect the E35 amplifier connector.
(c) Measure the resistance according to the value(s) in the table below.
Standard Resistance:
|
Tester Connection |
Condition |
Specified Condition |
|---|---|---|
|
z37-2 (-) - E35-2 (SG-6) |
Always |
Below 1 Ω |
|
z37-1 (+) - E35-19 (TR7) |
||
|
E35-19 (TR7) - Body ground |
Always |
0.3 to 8.0 kΩ |
|
E35-2 (SG-6) - Body ground |
Always |
Below 1 Ω |
|
|
|