DTC B1B71:11, B1B71:13 [FULL-AUTO AIR CONDITIONER]

id0702c1817100

DTC B1B71:11

Evaporator temperature sensor circuit short to ground

DTC B1B71:13

Evaporator temperature sensor circuit open
DETECTION CONDITION
CPU detects malfunction in evaporator temperature sensor circuit
POSSIBLE CAUSE
•  Evaporator temperature sensor malfunction
•  Open circuit in wiring harness between climate control unit connector terminal 2E and evaporator temperature sensor connector terminal B
•  Open circuit in wiring harness between climate control unit connector terminal 2L and evaporator temperature sensor connector terminal A
•  Short to ground in wiring harness between climate control unit connector terminal 2E and evaporator temperature sensor connector terminal B
•  Connector or terminal malfunction

Diagnostic procedure

STEP

INSPECTION

ACTION
1
INSPECT EVAPORATOR TEMPERATURE SENSOR
•  Inspect the evaporator temperature sensor. (See EVAPORATOR TEMPERATURE SENSOR INSPECTION [FULL-AUTO AIR CONDITIONER].)
•  Is it normal?
Yes
Go to the next step.
No
Replace the evaporator temperature sensor. (See EVAPORATOR TEMPERATURE SENSOR REMOVAL/INSTALLATION [FULL-AUTO AIR CONDITIONER].)
2
INSPECT EVAPORATOR TEMPERATURE SENSOR CIRCUIT FOR OPEN CIRCUIT
•  Disconnect the climate control unit connector and the evaporator temperature sensor connector.
•  Is there an open circuit in the wiring harness between the following terminals of the climate control unit and the evaporator temperature sensor?
―  2E—B
―  2L—A
Yes
Repair the wiring harness.
No
Go to the next step.
3
INSPECT EVAPORATOR TEMPERATURE SENSOR CIRCUIT FOR SHORT TO GROUND
•  Is there a short circuit to ground in the wiring harness between climate control unit terminal 2E and evaporator temperature sensor terminal B?
Yes
Repair the wiring harness.
No
Connect the climate control unit connector, then go to the next step.
4
INSPECT EVAPORATOR TEMPERATURE SENSOR CIRCUIT
•  Switch ignition to ON.
•  Inspect the voltage at the following climate control unit terminal (wiring harness-side).
―  Terminal 2E (evaporator temperature sensor input signal)
•  Is the voltage normal? (Approx. 5 V)
Yes
The system is normal at present. (Clear the past malfunction from the memory.)
No
Inspect the connection of the climate control unit connector.