DTC B1B71:11, B1B71:13 [CLIMATE CONTROL UNIT (MANUAL AIR CONDITIONER)]


id0702k3817100

System malfunction location

•  B1B71:11: Evaporator temperature sensor circuit short to ground
•  B1B71:13: Evaporator temperature sensor circuit open
Detection condition
•  Malfunction in wiring harness between evaporator temperature sensor and climate control unit
Fail-safe function
•  A/C output OFF is controlled when the evaporator temperature sensor input value is at 0 °C {32 °F}.
Possible cause
•  Connector or terminal malfunction
•  Evaporator temperature sensor malfunction
•  Open circuit in wiring harness between the following terminals:
―  Climate control unit terminal J—evaporator temperature sensor terminal B
―  Climate control unit terminal E—evaporator temperature sensor terminal A
•  Short to ground in wiring harness between the following terminals:
―  Climate control unit terminal J—evaporator temperature sensor terminal B
•  Climate control unit malfunction


Diagnostic procedure

STEP

INSPECTION

ACTION

1
INSPECT EVAPORATOR TEMPERATURE SENSOR CONNECTOR
•  Switch the ignition off.
•  Disconnect the evaporator temperature sensor connector.
•  Inspect the connector and terminals (corrosion, damage, pin disconnection).
•  Are the connector and terminals normal?
Yes
Go to the next step.
No
Repair/replace the connector or terminal.
After repair procedure, go to Step 6.
2
INSPECT EVAPORATOR TEMPERATURE SENSOR
•  Inspect the evaporator temperature sensor.
•  Is it normal?
Yes
Go to the next step.
No
Replace the evaporator temperature sensor.
Go to Step 6.
3
INSPECT EVAPORATOR TEMPERATURE SENSOR CIRCUIT FOR OPEN CIRCUIT
•  Disconnect the climate control unit connector.
•  Inspect for continuity between the following terminals (wiring harness-side):
―  Climate control unit terminal J—evaporator temperature sensor terminal B
―  Climate control unit terminal E—evaporator temperature sensor terminal A
•  Is there continuity?
Yes
Go to the next step.
No
Refer to the wiring diagram and verify whether or not there is a common connector between climate control unit terminal and evaporator temperature sensor terminal.
If there is a common connector:
•  Determine the malfunctioning part by inspecting the common connector and the terminal for corrosion, damage, or pin disconnection, and the common wiring harness for an open circuit.
•  Repair or replace the malfunctioning part.
If there is no common connector:
•  Repair or replace the wiring harness which has an open circuit.
Go to Step 6.
4
INSPECT EVAPORATOR TEMPERATURE SENSOR CIRCUIT FOR SHORT TO GROUND
•  Inspect for continuity between the following terminal (wiring harness-side) and body ground:
―  Climate control unit terminal J
•  Is there continuity?
Yes
Refer to the wiring diagram and verify whether or not there is a common connector between climate control unit terminal and evaporator temperature sensor terminal.
If there is a common connector:
•  Determine the malfunctioning part by inspecting the common connector and the terminal for corrosion, damage, or pin disconnection, and the common wiring harness for a short to ground.
•  Repair or replace the malfunctioning part.
If there is no common connector:
•  Repair or replace the wiring harness which has a short to ground.
Go to Step 6.
No
Go to the next step.
5
VERIFY CLIMATE CONTROL UNIT CONNECTOR CONDITION
•  Inspect the connector and terminals (corrosion, damage, pin disconnection).
•  Are the connector and terminals normal?
Yes
Go to the next step.
No
Repair/replace the connector or terminal.
After repair procedure, go to the next step.
6
VERIFY THAT SAME DTC IS NOT OUTPUT AGAIN
•  Reconnect the disconnected connectors.
•  Clear the DTC from the climate control unit memory using the M-MDS.
•  Perform the DTC inspection for the climate control unit using the M-MDS.
•  Is the same DTC displayed?
Yes
Repeat the inspection from Step 1.
•  If the malfunction recurs, replace the climate control unit.
Go to the next step.
No
Go to the next step.
7
VERIFY THAT NO OTHER DTCs ARE PRESENT
•  Verify other DTCs displayed.
•  Are any other DTCs displayed?
Yes
Repair or replace the malfunctioning part according to the applicable DTC troubleshooting.
No
DTC troubleshooting completed.