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

id0702c1817100

With Dual Type Climate Control Unit

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 climate control unit and evaporator temperature sensor •  Short to ground in wiring harness between climate control unit and evaporator temperature sensor •  Climate control unit malfunction

Diagnostic Procedure

Step	Inspection		Action
1	INSPECT EVAPORATOR TEMPERATURE SENSOR CONNECTOR •  Switch the ignition off. •  Disconnect the negative battery cable. (See NEGATIVE BATTERY CABLE DISCONNECTION/CONNECTION [SKYACTIV-D 1.5].) (See NEGATIVE BATTERY CABLE DISCONNECTION/CONNECTION [SKYACTIV-D 2.2].) (See NEGATIVE BATTERY CABLE DISCONNECTION/CONNECTION [SKYACTIV-G 1.5, SKYACTIV-G 2.0, SKYACTIV-G 2.5].) (See NEGATIVE BATTERY CABLE DISCONNECTION/CONNECTION [MZR 1.6].) •  Disconnect the evaporator temperature sensor connector. (See EVAPORATOR TEMPERATURE SENSOR INSPECTION [FULL-AUTO AIR CONDITIONER].) •  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.
2	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 A/C UNIT DISASSEMBLY/ASSEMBLY.) Go to the next step.
3	INSPECT EVAPORATOR TEMPERATURE SENSOR CIRCUIT FOR OPEN CIRCUIT •  Disconnect the climate control unit connector. (See CLIMATE CONTROL UNIT REMOVAL/INSTALLATION [FULL-AUTO AIR CONDITIONER].) •  Disconnect the evaporator temperature sensor connector. (See EVAPORATOR TEMPERATURE SENSOR INSPECTION [FULL-AUTO AIR CONDITIONER].) •  Inspect for continuity between the following terminals (wiring harness-side): ―  Climate control unit terminal 1J—evaporator temperature sensor terminal A ―  Climate control unit terminal 1L—evaporator temperature sensor terminal B •  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 the next step.
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 1L •  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 the next step.
		No	Connect the climate control unit connector, then 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 malfunctioning vehicle wiring harness, connector, or terminal. After repair procedure, go to the next step.
6	INSPECT EVAPORATOR TEMPERATURE SENSOR CIRCUIT •  Connect the climate control unit connector. •  Connect the negative battery cable. (See NEGATIVE BATTERY CABLE DISCONNECTION/CONNECTION [SKYACTIV-D 1.5].) (See NEGATIVE BATTERY CABLE DISCONNECTION/CONNECTION [SKYACTIV-D 2.2].) (See NEGATIVE BATTERY CABLE DISCONNECTION/CONNECTION [SKYACTIV-G 1.5, SKYACTIV-G 2.0, SKYACTIV-G 2.5].) (See NEGATIVE BATTERY CABLE DISCONNECTION/CONNECTION [MZR 1.6].) •  Switch the ignition ON (engine off or on). •  Inspect the voltage at the following climate control unit terminal (wiring harness-side). ―  Terminal 1L (evaporator temperature sensor input signal) •  Is the voltage normal? (Approx. 5 V)	Yes	The system is normal at present. Go to the next step.
		No	Go to the next step.
7	VERIFY THAT SAME DTC IS NOT OUTPUT AGAIN •  Switch the ignition off. •  Disconnect the negative battery cable. •  Reconnect the disconnected connectors. •  Connect the negative battery cable. (See NEGATIVE BATTERY CABLE DISCONNECTION/CONNECTION [SKYACTIV-D 1.5].) (See NEGATIVE BATTERY CABLE DISCONNECTION/CONNECTION [SKYACTIV-D 2.2].) (See NEGATIVE BATTERY CABLE DISCONNECTION/CONNECTION [SKYACTIV-G 1.5, SKYACTIV-G 2.0, SKYACTIV-G 2.5].) (See NEGATIVE BATTERY CABLE DISCONNECTION/CONNECTION [MZR 1.6].) •  Clear the past malfunction from memory. •  Verify DTCs. (See DTC DISPLAY [FULL-AUTO AIR CONDITIONER].) •  Is DTC B1B71:11 or B1B71:13 output?	Yes	Repeat the inspection from Step 1. •  If the malfunction does not recur, go to the next step. •  If the malfunction recurs, replace the climate control unit. (See CLIMATE CONTROL UNIT REMOVAL/INSTALLATION [FULL-AUTO AIR CONDITIONER].) Go to the next step.
		No	Go to the next step.
8	VERIFY THAT NO OTHER DTCs ARE PRESENT •  Verify other DTCs displayed. (See DTC DISPLAY [FULL-AUTO AIR CONDITIONER].) •  Are any other DTCs output?	Yes	Perform the corresponding DTC inspection. (See DTC TABLE [FULL-AUTO AIR CONDITIONER].)
		No	DTC troubleshooting completed.

With Single Type Climate Control Unit

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 climate control unit and evaporator temperature sensor •  Short to ground in wiring harness between climate control unit and evaporator temperature sensor •  Climate control unit malfunction

Diagnostic procedure

STEP	INSPECTION		ACTION
1	INSPECT EVAPORATOR TEMPERATURE SENSOR CONNECTOR •  Switch the ignition off. •  Disconnect the negative battery cable. (See NEGATIVE BATTERY CABLE DISCONNECTION/CONNECTION [SKYACTIV-G 1.5, SKYACTIV-G 2.0, SKYACTIV-G 2.5].) (See NEGATIVE BATTERY CABLE DISCONNECTION/CONNECTION [MZR 1.6].) •  Disconnect the evaporator temperature sensor connector. (See EVAPORATOR TEMPERATURE SENSOR INSPECTION [FULL-AUTO AIR CONDITIONER].) •  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.
2	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 A/C UNIT DISASSEMBLY/ASSEMBLY.) Go to the next step.
3	INSPECT EVAPORATOR TEMPERATURE SENSOR CIRCUIT FOR OPEN CIRCUIT •  Disconnect the climate control unit connector. (See CLIMATE CONTROL UNIT REMOVAL/INSTALLATION [FULL-AUTO AIR CONDITIONER].) •  Disconnect the evaporator temperature sensor connector. (See EVAPORATOR TEMPERATURE SENSOR INSPECTION [FULL-AUTO AIR CONDITIONER].) •  Inspect for continuity between the following terminals (wiring harness-side): ―  Climate control unit terminal E—evaporator temperature sensor terminal A ―  Climate control unit terminal J—evaporator temperature sensor terminal B •  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 the next step.
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 the next step.
		No	Connect the climate control unit connector, then 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 malfunctioning vehicle wiring harness, connector, or terminal. After repair procedure, go to the next step.
6	INSPECT EVAPORATOR TEMPERATURE SENSOR CIRCUIT •  Connect the climate control unit connector. •  Connect the negative battery cable. (See NEGATIVE BATTERY CABLE DISCONNECTION/CONNECTION [SKYACTIV-G 1.5, SKYACTIV-G 2.0, SKYACTIV-G 2.5].) (See NEGATIVE BATTERY CABLE DISCONNECTION/CONNECTION [MZR 1.6].) •  Switch the ignition ON (engine off or on). •  Inspect the voltage at the following climate control unit terminal (wiring harness-side). ―  Terminal J (evaporator temperature sensor input signal) •  Is the voltage normal? (Approx. 5 V)	Yes	The system is normal at present. Go to the next step.
		No	Go to the next step.
7	VERIFY THAT SAME DTC IS NOT OUTPUT AGAIN •  Switch the ignition off. •  Disconnect the negative battery cable. •  Reconnect the disconnected connectors. •  Connect the negative battery cable. (See NEGATIVE BATTERY CABLE DISCONNECTION/CONNECTION [SKYACTIV-G 1.5, SKYACTIV-G 2.0, SKYACTIV-G 2.5].) (See NEGATIVE BATTERY CABLE DISCONNECTION/CONNECTION [MZR 1.6].) •  Clear the past malfunction from memory. (See CLEARING DTC [FULL-AUTO AIR CONDITIONER].) •  Verify DTCs. (See DTC DISPLAY [FULL-AUTO AIR CONDITIONER].) •  Is DTC B1B71:11 or B1B71:13 output?	Yes	Repeat the inspection from Step 1. •  If the malfunction does not recur, go to the next step. •  If the malfunction recurs, replace the climate control unit. (See CLIMATE CONTROL UNIT REMOVAL/INSTALLATION [FULL-AUTO AIR CONDITIONER].) Go to the next step.
		No	Go to the next step.
8	VERIFY THAT NO OTHER DTCs ARE PRESENT •  Verify other DTCs displayed. (See DTC DISPLAY [FULL-AUTO AIR CONDITIONER].) •  Are any other DTCs output?	Yes	Perform the corresponding DTC inspection. (See DTC TABLE [FULL-AUTO AIR CONDITIONER].)
		No	DTC troubleshooting completed.