Toyota Camry (XV70): Pressure Sensor Circuit
DESCRIPTION
Based on signals from the air conditioner pressure sensor, the air conditioning amplifier assembly controls the compressor solenoid of the compressor assembly with pulley and changes the air inlet mode between fresh and recirculation in order to protect the parts of the refrigerant cycle.
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) |
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|
*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:
SEE MORE:
Vehicle Speed Signal Circuit between Stereo Component Amplifier and Combination Meter
DESCRIPTION The stereo component amplifier assembly receives a vehicle speed signal from the combination meter assembly to control the ASL function.
HINT:
A voltage of 12 V or 5 V is output from each ECU and then input to the combination meter assembly. The signal is changed to a pulse signal
Installation
INSTALLATION PROCEDURE 1. INSTALL FUEL SUCTION TUBE WITH PUMP AND GAUGE ASSEMBLY
(a) Install a new fuel suction tube set gasket to the fuel tank assembly.
(b) Set the fuel suction tube with pump and gauge assembly to the fuel tank assembly.
NOTICE: Be careful not to bend the arm of the fuel se
