Toyota Corolla Cross: Room Temperature Sensor Circuit Short to Battery or Open (B141A15)
DESCRIPTION
The cooler thermistor (room temperature sensor) is installed in the instrument panel to detect the cabin temperature, which is used to control the air conditioning system. The resistance of the cooler thermistor (room temperature sensor) changes in accordance with the cabin temperature. As the temperature decreases, the resistance increases. As the temperature increases, the resistance decreases.
The air conditioning amplifier assembly applies voltage (5 V) to the cooler thermistor (room temperature sensor) and reads voltage changes due to changes in the resistance of the cooler thermistor (room temperature sensor).
|
DTC No. | Detection Item |
DTC Detection Condition | Trouble Area |
Memory |
|---|---|---|---|---|
| B141A15 |
Room Temperature Sensor Circuit Short to Battery or Open |
Diagnosis Condition:
Malfunction Status:
Detection Time:
|
| Memorized |
|
Vehicle Condition | |||
|---|---|---|---|
|
Pattern 1 | Pattern 2 | ||
|
Diagnosis Condition | Ignition switch ON |
○ | ○ |
|
Malfunction | Open in room temperature sensor circuit |
○ | - |
|
Short in room temperature sensor circuit |
- | ○ | |
|
Detection Time | Continuously for 4 seconds or more |
Continuously for 4 seconds or more | |
|
Trip Count | 1 trip |
1 trip | |
HINT:
If the conditions of either of these patterns are detected, a DTC will be stored
WIRING DIAGRAM
PROCEDURE
| 1. |
READ VALUE USING GTS |
(a) Read the Data List according to the display on the GTS.
Body Electrical > Air Conditioner > Data List|
Tester Display | Measurement Item |
Range | Normal Condition |
Diagnostic Note |
|---|---|---|---|---|
|
Room Temperature Sensor |
Cooler thermistor (room temperature sensor) |
Min.: -327.68°C (-557.82°F) Max.: 327.67°C (621.81°F) |
Actual cabin temperature displayed |
Cooler thermistor (room temperature sensor) circuit malfunction |
|
Tester Display |
|---|
| Room Temperature Sensor |
OK:
The display is as specified in the normal condition column.
| OK | .gif) | REPLACE AIR CONDITIONING AMPLIFIER ASSEMBLY |
|
.gif)
| 2. |
INSPECT COOLER THERMISTOR (ROOM TEMPERATURE SENSOR) |
Click here .gif)
| NG | | REPLACE COOLER THERMISTOR (ROOM TEMPERATURE SENSOR) |
|
| 3. |
CHECK HARNESS AND CONNECTOR (COOLER THERMISTOR (ROOM TEMPERATURE SENSOR) - AIR CONDITIONING AMPLIFIER ASSEMBLY) |
(a) Disconnect the I48 air conditioning amplifier assembly connector.
(b) Measure the resistance according to the value(s) in the table below.
Standard Resistance:
|
Tester Connection | Condition |
Specified Condition |
|---|---|---|
|
I227-1 - I48-5 (TR) | Always |
Below 1 Ω |
|
I227-2 - I48-3 (SG-1) |
Always | Below 1 Ω |
|
I227-1 or I48-5 (TR) - Other terminals and body ground |
Always | 10 kΩ or higher |
|
I227-2 or I48-3 (SG-1) - Other terminals and body ground |
Always | 10 kΩ or higher |
| OK | | REPLACE AIR CONDITIONING AMPLIFIER ASSEMBLY |
| NG | | REPAIR OR REPLACE HARNESS OR CONNECTOR |
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