Toyota Camry (XV70): Pressure Sensor Circuit
DESCRIPTION
Based on signals from the air conditioner pressure sensor, the air conditioning amplifier assembly controls the compressor assembly with pulley (compressor solenoid)*1 or cooler compressor assembly (compressor solenoid)*2 and changes the air inlet mode between fresh and recirculation in order to protect the parts of the refrigerant cycle.
- *1: for A25A-FKS
- *2: for 2GR-FKS
WIRING DIAGRAM
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PROCEDURE
| 1. |
CHECK HARNESS AND CONNECTOR (POWER SOURCE CIRCUIT) |
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|
*a | Front view of wire harness connector (to Air Conditioner Pressure Sensor) |
(a) Disconnect the A18 air conditioner pressure sensor connector.
(b) Measure the voltage according to the value(s) in the table below.
Standard Voltage:
|
Tester Connection | Condition |
Specified Condition |
|---|---|---|
|
A18-3 (+) - Body ground |
Ignition switch ON | 4.75 to 5.25 V |
| NG | .gif) | GO TO STEP 6 |
|
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| 2. |
CHECK HARNESS AND CONNECTOR (AIR CONDITIONER PRESSURE SENSOR - BODY GROUND) |
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|
*a | Front view of wire harness connector (to Air Conditioner Pressure Sensor) |
(a) Measure the resistance according to the value(s) in the table below.
Standard Resistance:
|
Tester Connection | Condition |
Specified Condition |
|---|---|---|
|
A18-1 (-) - Body ground |
Always | Below 1 ? |
| NG | | GO TO STEP 5 |
|
| 3. |
CHECK HARNESS AND CONNECTOR (AIR CONDITIONER PRESSURE SENSOR - AIR CONDITIONING AMPLIFIER ASSEMBLY) |
(a) Disconnect the K55 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 |
|---|---|---|
|
A18-2 (PR) - K55-24 (PRE) |
Always | Below 1 ? |
|
A18-2 (PR) or K55-24 (PRE) - Other terminals and body ground |
Always | 10 k? or higher |
| NG | | REPAIR OR REPLACE HARNESS OR CONNECTOR |
|
| 4. |
INSPECT AIR CONDITIONER PRESSURE SENSOR (SENSOR SIGNAL CIRCUIT) |
|
*a | Component with harness connected (Air Conditioning Amplifier Assembly) |
(a) Measure the voltage with the following conditions met.
Measurement Condition:|
Item | Condition |
|---|---|
|
Vehicle doors | Fully open |
|
Temperature setting | MAX COLD |
|
Blower speed | HI |
|
A/C switch | On |
|
Recirculation/fresh switch |
RECIRCULATION |
|
Interior temperature |
25 to 35°C (77 to 95°F) |
NOTICE:
- If refrigerant pressure on the high pressure side becomes extremely high during the inspection (if the voltage exceeds 4.61 V), a fail-safe function will stop compressor operation. In this case, make sure to measure the voltage before the fail-safe function operates.
- It is necessary to measure the voltage for a certain amount of time (approximately 10 minutes) because the malfunction may recur after a while.
HINT:
When the ambient air temperature is low (below -1.5°C (29.3°F)), the compressor with pulley will be stopped, due to inputs of the thermistor assembly and No. 1 cooler thermistor, to prevent the evaporator from freezing. In this case, perform the inspection in a warm indoor environment.
(1) Measure the voltage according to the value(s) in the table below.
Standard Voltage:
|
Tester Connection | Condition |
Specified Condition |
|---|---|---|
|
K55-24 (PRE) - Body ground |
Ignition switch ON (A/C switch: On) |
0.74 to 4.61 V |
(b) Connect the Techstream to the DLC3.
(c) Turn the ignition switch to ON.
(d) Turn the Techstream on.
(e) Enter the following menus: Body Electrical / Air Conditioner / Data List.
(f) Read the Data List according to the display on the Techstream.
Body Electrical > Air Conditioner > Data List|
Tester Display | Measurement Item |
Range | Normal Condition |
Diagnostic Note |
|---|---|---|---|---|
|
Regulator Pressure Sensor |
Air conditioner pressure sensor |
Min.: -456.68 kPaG Max.: 3294.37 kPaG |
Actual refrigerant pressure displayed |
- |
|
Tester Display |
|---|
| Regulator Pressure Sensor |
OK:
The voltage and value displayed in the Data List change.
|
Result | Proceed to |
|---|---|
|
OK | A |
|
NG (The voltage changes but the value displayed in the Data List does not change.) | |
|
NG (The voltage does not change.) |
B |
| A |
| REPLACE AIR CONDITIONING AMPLIFIER ASSEMBLY
|
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| B |
| REPLACE AIR CONDITIONER PRESSURE SENSOR
|
| 5. |
CHECK HARNESS AND CONNECTOR (AIR CONDITIONER PRESSURE SENSOR - AIR CONDITIONING AMPLIFIER ASSEMBLY) |
(a) Disconnect the K55 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 |
|---|---|---|
|
K55-3 (SG-4) - A18-1 (-) |
Always | Below 1 ? |
|
K55-3 (SG-4) or A18-1 (-) - Other terminals and body ground |
Always | 10 k? or higher |
| OK | | REPLACE AIR CONDITIONING AMPLIFIER ASSEMBLY
|
| NG | | REPAIR OR REPLACE HARNESS OR CONNECTOR |
| 6. |
CHECK HARNESS AND CONNECTOR (AIR CONDITIONER PRESSURE SENSOR - AIR CONDITIONING AMPLIFIER ASSEMBLY) |
(a) Disconnect the K55 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 |
|---|---|---|
|
K55-6 (S5-3) - A18-3 (+) |
Always | Below 1 ? |
|
K55-6 (S5-3) or A18-3 (+) - Other terminals and body ground |
Always | 10 k? or higher |
| OK | | REPLACE AIR CONDITIONING AMPLIFIER ASSEMBLY
|
| NG | | REPAIR OR REPLACE HARNESS OR CONNECTOR |
READ NEXT:
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DESCRIPTION If warm air blows from the registers regardless of the temperature setting of the air conditioning system, the following suspected areas may be the cause.
Symptom Factor
No c
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Symptom Factor
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SEE MORE:
Components
COMPONENTS ILLUSTRATION
*A w/ Smart Key System
- -
*1 ECU INTEGRATION BOX RH
*2 LOWER INSTRUMENT PANEL SUB-ASSEMBLY
*3 CENTRAL GATEWAY ECU (NETWORK GATEWAY ECU)
- -
N*m (kgf*cm, ft.*lbf): Specified torque
- - ILLUSTRAT
Data List / Active Test
DATA LIST / ACTIVE TEST DATA LIST NOTICE:
In the table below, the values listed under "Normal Condition" are reference values. Do not depend solely on these reference values when deciding whether a part is faulty or not.
HINT: Using the Techstream to read the Data List allows the values or states
