- Open or short in pressure sensor circuit
- Refrigerant pressure on the high pressure side is extremely low (0.19 MPa (2.0 kgf/cm2, 28 psi) or less) or extremely high (3.14 MPa (32.0 kgf/cm2, 455 psi) or more).
| Last Modified: 11-29-2007 | 1.6 C | |
| Service Category: Vehicle Interior | Section: Heating/Air Conditioning | |
| Model Year: 2008 | Model: Sequoia | Doc ID: RM000000STP01XX |
| Title: HEATING / AIR CONDITIONING: AIR CONDITIONING SYSTEM: DESCRIPTION (2008 Sequoia) | ||
|
DTC |
B1423/23 |
Pressure Sensor Circuit |
DESCRIPTION
This DTC is output when refrigerant pressure on the high pressure side is extremely low (0.19 MPa (2.0 kgf/cm2, 28 psi) or less) or extremely high (3.14 MPa (32.0 kgf/cm2, 455 psi) or more). The pressure sensor, which is installed on the pipe of the high pressure side to detect refrigerant pressure, outputs a refrigerant pressure signal to the air conditioning amplifier. The air conditioning amplifier converts this signal to pressure according to the sensor characteristics to control the compressor.
|
DTC Code |
DTC Detection Condition |
Trouble Area |
|---|---|---|
|
B1423/23 |
|
|
WIRING DIAGRAM
INSPECTION PROCEDURE
PROCEDURE
|
1. |
CHECK REFRIGERANT PRESSURE |
|
(a) Install the manifold gauge set
|
(b) Read the manifold gauge pressure when the following conditions are established.
(1) Prepare the vehicle in accordance with the chart below.
|
Item |
Condition |
|---|---|
|
Engine speed |
1500 rpm |
|
Vehicle doors |
Fully open |
|
Temperature setting |
MAX COLD |
|
Blower speed |
HI |
|
A/C switch |
ON |
|
Air inlet |
RECIRC |
(2) When the refrigerant volume is correct, the gauge reading indicates as follows:
Standard:
|
Refrigerant Pressure |
Specified Condition |
|---|---|
|
Low pressure side |
0.15 to 0.25 MPa (1.5 to 2.5 kgf/cm2, 22 to 36 psi) |
|
High pressure side |
1.37 to 1.57 MPa (14 to 16 kgf/cm2, 199 to 228 psi) |
HINT:
Pressure varies in accordance with certain conditions (outside air temperature, sunlight and wind).
|
|
2. |
READ VALUE USING TECHSTREAM (REGULATOR PRESSURE SENSOR) |
(a) Warm up the engine.
(b) Turn the ignition switch off.
(c) Connect the Techstream to the DLC3.
(d) Turn the ignition switch to ON.
(e) Turn the Techstream on.
(f) Enter the following menus: Body Electrical / Air Conditioner / Data List / Regulator Pressure Sensor.
(g) According to the display on the Techstream, read the Data List.
Regulator Pressure Sensor:
|
Tester Display |
Measurement Item/Range |
Normal Condition |
Diagnostic Note |
|---|---|---|---|
|
Regulator Pressure Sensor |
Regulator pressure sensor / Min.: 0 kgf/cm2G, Max.: 38.25 kgf/ cm2G |
Actual refrigerant pressure is displayed |
- |
OK:
The display is as specified in the normal condition.
Result
|
Result |
Proceed to |
|---|---|
|
NG |
A |
|
OK (When troubleshooting according to Problem Symptoms Table) |
B |
|
OK (When troubleshooting according to the DTC output) |
C |
|
|
3. |
INSPECT AIR CONDITIONING PRESSURE SENSOR |
(a) Install the manifold gauge set
.
(b) Disconnect the A22 air conditioning pressure sensor connector.
(c) Connect the three 1.5 V dry cell batteries' positive (+) lead to terminal 3, and the negative (-) lead to terminal 1.
(d) Connect the voltmeter positive (+) lead to terminal 2, and the negative (-) lead to terminal 1.
(e) Measure the voltage according to the value(s) in the table below.
Standard Voltage:
|
Tester Connection |
Condition |
Specified Condition |
|---|---|---|
|
1 - 2 |
Refrigerant pressure: 0.39 to 3.187 MPa (4 to 32.5 kgf/cm2, 57 to 463 psi) |
1.0 to 4.8 V |
(f) Reconnect the air conditioning pressure sensor connector.
|
|
4. |
CHECK HARNESS AND CONNECTOR (A/C PRESSURE SENSOR - A/C AMPLIFIER, BODY GROUND) |
|
(a) Disconnect the A22 air conditioning pressure sensor connector. |
(b) Disconnect the H24 air conditioning amplifier connector.
(c) Measure the resistance according to the value(s) in the table below.
Standard Resistance:
|
Tester Connection |
Condition |
Specified Condition |
|---|---|---|
|
A22-1 (-) - Body ground |
Always |
Below 1 Ω |
|
A22-2 (PR) - H24-9 (PRE) |
Always |
Below 1 Ω |
|
A22-3 (+) - H24-10 (S5-3) |
Always |
Below 1 Ω |
|
A22-2 (PR) - Body ground |
Always |
10 kΩ or higher |
|
A22-3 (+) - Body ground |
Always |
10 kΩ or higher |
(d) Reconnect the air conditioning amplifier connector.
(e) Reconnect the A/C pressure sensor connector.
|
|
5. |
CHECK FOR A/C SYSTEM LEAK |
(a) Install the manifold gauge set
.
(b) Recover the refrigerant from the A/C system using a refrigerant recovery unit.
(c) Evacuate the A/C system and check that vacuum can be maintained in it.
OK:
Vacuum can be maintained in the A/C system.
HINT:
If vacuum cannot be maintained in the A/C system, refrigerant may be leaking from it. In this case, it is necessary to repair or replace the leaking part of the A/C system.
|
|
6. |
CHARGE REFRIGERANT |
(a) Add an appropriate amount of refrigerant
.
|
|
7. |
RECHECK DTC |
(a) Recheck for the DTC when the following conditions are satisfied.
|
Item |
Condition |
|---|---|
|
Vehicle Doors |
Fully open |
|
Temperature Setting |
MAX COLD |
|
Blower Speed |
HI |
|
A/C Switch |
ON |
|
R/F Switch |
RECIRCULATION |
|
Interior Temperature |
25 to 35°C (77 to 95°F) or higher |
|
Engine Speed |
2000 rpm |
NOTICE:
If refrigerant pressure on the high pressure side becomes high, the DTC will be set. Therefore, it is necessary to measure the voltage for a certain amount of time (approximately 10 minutes) because the DTC may be set after the A/C operates for a while.
HINT:
When the outside air temperature is low (below -1.5°C (29.3°F)), the compressor stops due to operation of the ambient temperature sensor and the evaporator temperature sensor to prevent the evaporator from freezing. In this case, perform the inspection in a warm indoor environment.
NOTICE:
If the DTC was stored due to an insufficient or excessive amount of refrigerant, the problem may have been solved after performing the previous step. However, the root cause of insufficient refrigerant may be refrigerant leaks. The root cause of excessive refrigerant may be adding refrigerant when the level was insufficient. Therefore, identify and repair the area where refrigerant leaks from as necessary.
Result
|
Result |
Proceed to |
|---|---|
|
DTC B1423 is output |
A |
|
DTC B1423 is not output |
B |
|
|
8. |
REPAIR A/C SYSTEM LEAK |
(a) Identify the area where refrigerant leaks from
.
(b) Repair the identified area of the A/C system.
(c) Evacuate the A/C system.
|
|
9. |
CHARGE REFRIGERANT |
(a) Use a refrigerant recovery unit to recover refrigerant.
(b) Evacuate the A/C system.
(c) Add an appropriate amount of refrigerant
.
HINT:
If refrigerant is added and the system has not been properly evacuated (insufficient vacuum time), moisture in the air remaining in the system may freeze in the expansion valve, blocking the flow on the high pressure side. Therefore, in order to confirm the problem, recover the refrigerant, properly evacuate the system, add an appropriate amount of refrigerant, and check for the DTC.
|
|
10. |
RECHECK DTC |
(a) Recheck for the DTC when the following conditions are satisfied.
|
Item |
Condition |
|---|---|
|
Vehicle Doors |
Fully open |
|
Temperature Setting |
MAX COLD |
|
Blower Speed |
HI |
|
A/C Switch |
ON |
|
R/F Switch |
RECIRCULATION |
|
Interior Temperature |
25 to 35°C (77 to 95°F) or higher |
|
Engine Speed |
2000 rpm |
NOTICE:
If refrigerant pressure on the high pressure side becomes high, the DTC will be set. Therefore, it is necessary to measure the voltage for a certain amount of time (approximately 10 minutes) because the DTC may be set after the A/C operates for a while.
HINT:
- When the outside air temperature is low (below -1.5°C (29.3°F)), the compressor stops due to operation of the ambient temperature sensor and the evaporator temperature sensor to prevent the evaporator from freezing. In this case, perform the inspection in a warm indoor environment.
- If refrigerant is added and the system has not been properly evacuated (insufficient vacuum time), moisture in the air remaining in the system may freeze in the expansion valve, blocking the flow on the high pressure side. Therefore, in order to confirm the problem, recover the refrigerant, properly evacuate the system, add an appropriate amount of refrigerant, and check for the DTC. If the DTC is not output after this work, it indicates that the cooler dryer in the condenser is not able to absorb moisture in the refrigerant cycle. In this case, to complete the repair it is necessary to replace the cooler dryer.
Result
|
Result |
Proceed to |
|---|---|
|
DTC B1423 is output |
A |
|
DTC B1423 is not output |
B |
|
|
|