Lexus SC300 / Lexus SC400. Manual — part 948

SENSOR INSPECTION FOR AIR CONDITIONING SYSTEM – AC005-04

December 16, 2004

Page 5 of 12

4. Inspect Evaporator Temperature Sensor.

Select the appropriate graph (specification) using the following table.

NOTE:

Please inspect the sensors for model years not indicated by this bulletin, according to
the instructions in the applicable repair manual.

MODEL

MODEL YEAR

COMMENTS

PART NUMBER

GRAPH

ES 300

1992 – 2001

88625–33070

2

ES 300/330

2002 – 2003

88625–17130

2

ES 300/330

2003

88625–33170

3

GS 300

1993 – 1997

88625–3A020

2

GS 300/400/430

1998 – 2002

88625–3A120

2

GX 470

2003

2005

Thermistor No. 1

88625–35050

3

GX 470

2003 – 2005

Thermistor No. 2

88625–16210

2

IS 300

2000 – 2001

88625–48010

2

1990 – 1992

88625–32040

2

LS 400

1993 – 1994

88625–50100

2

1995 – 2000

88625–50140

2

LS 430

2001 – 2005

88625–50160

2

LX 450

1996 – 1997

88625–60060

2

1998 – 2000

Thermistor No. 2

88625–60140

2

LX 470

1998 – 2002

Thermistor No. 1

88625–60130

2

2003 – 2005

88625–47011

2

RX 300

1998 – 2003

88625–48010

2

2004

CBU

88625–48050

1

RX 330

2004

2005

CBU

88625 48060

3

2004 – 2005

NAP

88625–48060

3

SC 300/400

1991 – 2000

88625–32040

2

Inspection

Procedure

(Continued)

SENSOR INSPECTION FOR AIR CONDITIONING SYSTEM – AC005-04

December 16, 2004

Page 6 of 12

A. Measure the sensor resistance according to the selected graph (specification).

NOTE:

S

Even slightly touching the sensor may change the resistance value.
Be sure to hold the connector of the sensor.

S

When measuring, the sensor temperature must be the same as the
ambient temperature.

HINT:

As the temperature increases, the resistance decreases.

Graph 1:

TEMPERATURE

°

F (

°

C)

SPECIFICATION k

Ω

14 (–10)

7.30 to 9.10

23 (–5)

5.65 to 6.95

32 (0)

4.40 to 5.35

41 (5)

3.40 to 4.15

50 (10)

2.70 to 3.25

59 (15)

2.14 to 2.58

68 (20)

1.71 to 2.05

77 (25)

1.38 to 1.64

86 (30)

1.11 to 1.32

Graph 2:

TEMPERATURE

°

F (

°

C)

SPECIFICATION k

Ω

14 (–10)

7.40 to 9.20

23 (–5)

5.65 to 7.00

32 (0)

4.35 to 5.40

41 (5)

3.40 to 4.20

50 (10)

2.68 to 3.30

59 (15)

2.10 to 2.60

68 (20)

1.66 to 2.10

77 (25)

1.32 to 1.66

86 (30)

1.05 to 1.35

Inspection

Procedure

(Continued)

Resistance
k

Ω

12.0

3.0
2.0

0.0

32

(0)

68

(20)

104

(40)

Temperature

°

F (

°

C)

Max

Min

1.0

4.0

8.0
7.0

5.0

6.0

9.0

10.0

11.0

–4

(–20)

32

(0)

68

(20)

104

(40)

–4

(–20)

Resistance
k

Ω

3.0

2.0

0.0

Temperature

°

F (

°

C)

Max

Min

1.0

4.0

8.0
7.0

5.0

6.0

9.0

10.0

SENSOR INSPECTION FOR AIR CONDITIONING SYSTEM – AC005-04

December 16, 2004

Page 7 of 12

Graph 3:

TEMPERATURE

°

F (

°

C)

SPECIFICATION k

Ω

14 (–10)

8.00 to 10.00

23 (–5)

6.15 to 7.65

32 (0)

4.75 to 5.85

41 (5)

3.70 to 4.55

50 (10)

2.91 to 3.55

59 (15)

2.32 to 2.80

68 (20)

1.85 to 2.22

77 (25)

1.48 to 1.77

86 (30)

1.20 to 1.43

Inspection

Procedure

(Continued)

32

(0)

68

(20)

104

(40)

–4

(–20)

Temperature

°

F (

°

C)

Resistance
k

Ω

12.0

3.0
2.0

0.0

Max

Min

1.0

4.0

8.0
7.0

5.0

6.0

9.0

10.0

11.0

SENSOR INSPECTION FOR AIR CONDITIONING SYSTEM – AC005-04

December 16, 2004

Page 8 of 12

5. Inspect Solar Sensor.

Four types of solar sensors are used on Lexus vehicles depending on the vehicle
specifications. The inspection procedure for each type of sensor differs from the
others. Select the appropriate inspection procedure from the table below according to
vehicle specifications and perform the inspection.

EQUIPPED WITH AUTOMATIC

LIGHT CONTROL SYSTEM

A/C SYSTEM WITH RIGHT/LEFT

INDEPENDENT TEMPERATURE CONTROL

INSPECTION

PROCEDURE

No

No

A

No

Yes

B

Yes

Yes

C

Yes

No

D

Procedure A:

a. Disconnect the solar

sensor connector.

b. Measure the resistance between

terminals 1 and 2 of the solar
sensor under the
following conditions:

S

Cover the sensor with a cloth
to avoid direct light.

S

Expose the sensor to light
from a distance of 300 mm
(11.81 in.) or less with an
inspection light.

NOTE:

S

Terminal 1 of the sensor is always on
the right, when the lock is facing up.

S

When using an analog tester, connect
the positive (+) lead to terminal 2 and
negative (–) lead to terminal 1 of the
solar sensor.

HINT:

If the light is weak, the sensor may not react. Be sure to use an incandescent light for
an inspection light.

Standard:

CONDITION

SPECIFICATION

When the sensor is covered with a cloth

(to avoid direct light)

Infinite ohms

When the sensor is exposed to light

Less than infinite resistance

Inspection

Procedure

(Continued)

Lock