| Last Modified: 07-31-2024 | 6.11:8.1.0 | Doc ID: RM100000001H97N |
| Model Year Start: 2020 | Model: Corolla | Prod Date Range: [01/2019 - 09/2022] |
| Title: HEATING / AIR CONDITIONING: AIR CONDITIONING SYSTEM (for HV Model): B14B8; Refrigerant Shortage; 2020 - 2022 MY Corolla Corolla HV [01/2019 - 09/2022] | ||
|
DTC |
B14B8 |
Refrigerant Shortage |
DESCRIPTION
This DTC is stored if the amount of refrigerant in the air conditioning system is insufficient.
The air conditioning amplifier assembly receives the ambient temperature signal, refrigerant pressure signal, etc. from various sensors.
Based on these signals, the air conditioning amplifier assembly detects the amount of refrigerant.
If the amount of refrigerant is insufficient, the A/C switch indicator will turn off and the air conditioning system will stop operating.
|
DTC No. |
Detection Item |
DTC Detection Condition |
Trouble Area |
Memory |
|---|---|---|---|---|
|
B14B8 |
Refrigerant Shortage |
The following condition is detected in the normal operation refrigerant shortage check: Amount of refrigerant is insufficient |
|
Memorized (10 min. or more)* |
- *: The air conditioning amplifier assembly stores this DTC if the malfunction has occurred for the period of time indicated in the brackets.
WIRING DIAGRAM
PROCEDURE
|
1. |
CHECK REFRIGERANT PRESSURE |
(a) Connect the Techstream to the DLC3.
(b) Turn the power switch on (IG).
(c) Turn the Techstream on.
(d) Enter the following menus: Body Electrical / Air Conditioner / Data List.
(e) 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 |
|
Body Electrical > Air Conditioner > Data List
|
Tester Display |
|---|
|
Regulator Pressure Sensor |
(f) Install a manifold gauge set.
for HFC-134a (R134a): Click here
![2020 - 2025 MY Corolla Corolla Hatchback Corolla HV GR Corolla [01/2019 - ]; HEATING / AIR CONDITIONING: REFRIGERANT (for HFC-134a(R134a)): ON-VEHICLE INSPECTION](/t3Portal/stylegraphics/info.gif)
for HFO-1234yf (R1234yf): Click here
(g) Read the manifold gauge set 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 |
30 to 35°C (86 to 95°F) |
Standard Pressure:
Low pressure side
150 to 250 kPa (1.5 to 2.5 kgf/cm2, 22 to 36 psi)
High pressure side
1370 to 1570 kPa (14 to 16 kgf/cm2, 199 to 228 psi)
(h) Compare the values displayed in the Data List and on the manifold gauge set.
OK:
The values displayed in the Data List and on the manifold gauge set match.
| OK |
|
INSPECT REFRIGERANT PRESSURE WITH MANIFOLD GAUGE SET for HFC-134a (R134a): Click here
for HFO-1234yf (R1234yf): Click here
|
|
|
2. |
CHECK HARNESS AND CONNECTOR (POWER SOURCE CIRCUIT) |
(a) Disconnect the A61 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 |
|---|---|---|
|
A61-3 (+) - Body ground |
Power switch on (IG) |
4.75 to 5.25 V |
| NG |
|
|
|
3. |
CHECK HARNESS AND CONNECTOR (AIR CONDITIONER PRESSURE SENSOR - BODY GROUND) |
(a) Measure the resistance according to the value(s) in the table below.
Standard Resistance:
|
Tester Connection |
Condition |
Specified Condition |
|---|---|---|
|
A61-1 (-) - Body ground |
Always |
Below 1 Ω |
| NG |
|
|
|
4. |
CHECK HARNESS AND CONNECTOR (AIR CONDITIONER PRESSURE 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 |
|---|---|---|
|
A61-2 (PR) - I48-6 (PRE) |
Always |
Below 1 Ω |
|
A61-2 (PR) or I48-6 (PRE) - Other terminals and body ground |
Always |
10 kΩ or higher |
| NG |
|
REPAIR OR REPLACE HARNESS OR CONNECTOR |
|
|
5. |
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 motor 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 |
|---|---|---|
|
I48-6 (PRE) - Body ground |
Power switch on (READY) (A/C switch: On) |
0.62 to 4.73 V* |
*: While sensor voltage is 5 V.
(b) Connect the to the DLC3.
(c) Turn the power switch on (IG).
(d) Turn the on.
(e) Enter the following menus: Body Electrical / Air Conditioner / Data List.
(f) Read the Data List according to the display on the .
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 |
|
Body Electrical > Air Conditioner > Data List
|
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 |
|
| B |
|
|
6. |
CHECK HARNESS AND CONNECTOR (AIR CONDITIONER PRESSURE 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 |
|---|---|---|
|
A61-1 (-) - I48-15 (SG-4) |
Always |
Below 1 Ω |
|
A61-1 (-) or I48-15 (SG-4) - Other terminals and body ground |
Always |
10 kΩ or higher |
| OK |
|
| NG |
|
REPAIR OR REPLACE HARNESS OR CONNECTOR |
|
7. |
CHECK HARNESS AND CONNECTOR (AIR CONDITIONER PRESSURE 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 |
|---|---|---|
|
A61-3 (+) - I48-11 (S5-3) |
Always |
Below 1 Ω |
|
A61-3 (+) or I48-11 (S5-3) - Other terminals and body ground |
Always |
10 kΩ or higher |
| OK |
|
| NG |
|
REPAIR OR REPLACE HARNESS OR CONNECTOR |
|
|