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DTC B1B71:15 [DASH-ELECTRICAL SUPPLY UNIT (E)]

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Outline

System malfunction location

Evaporator temperature sensor circuit malfunction

Detection condition

•  The dash-electrical supply unit detects an open circuit in evaporator temperature sensor circuit.

Fail-safe

•  Fixes the evaporator temperature sensor input value at 0 °C {32 °F} and performs control.

Possible cause

•  Evaporator temperature sensor connector or terminal malfunction

•  Evaporator temperature sensor malfunction

•  Dash-electrical supply unit connector or terminal malfunction

•  Open circuit in any of the following evaporator temperature sensor circuits

―  Signal circuit

―  Ground circuit

•  Dash-electrical supply unit malfunction

System malfunction location	Evaporator temperature sensor circuit malfunction
Detection condition	• The dash-electrical supply unit detects an open circuit in evaporator temperature sensor circuit.
Fail-safe	• Fixes the evaporator temperature sensor input value at 0 °C {32 °F} and performs control.
Possible cause	• Evaporator temperature sensor connector or terminal malfunction • Evaporator temperature sensor malfunction • Dash-electrical supply unit connector or terminal malfunction • Open circuit in any of the following evaporator temperature sensor circuits ― Signal circuit ― Ground circuit • Dash-electrical supply unit malfunction

Diagnostic Procedure

Step

Inspection

Results

Action

1

INSPECT EVAPORATOR TEMPERATURE SENSOR CONNECTOR FOR MALFUNCTION

•  Inspect the applicable connector and terminal.
(See CONNECTOR INSPECTION.)

•  Are the connector and terminal normal?

Yes

Go to the next step.

No

Repair or replace the malfunctioning location and perform the repair completion verification.

2

INSPECT EVAPORATOR TEMPERATURE SENSOR FOR MALFUNCTION

•  Inspect the applicable part.
(See EVAPORATOR TEMPERATURE SENSOR INSPECTION [MANUAL AIR CONDITIONER].)

(See EVAPORATOR TEMPERATURE SENSOR INSPECTION [FULL-AUTO AIR CONDITIONER].)

•  Is the part normal?

Yes

Go to the next step.

No

Repair or replace the malfunctioning location and perform the repair completion verification.

(See EVAPORATOR TEMPERATURE SENSOR REMOVAL/INSTALLATION [MANUAL AIR CONDITIONER (E)].)

(See EVAPORATOR TEMPERATURE SENSOR REMOVAL/INSTALLATION [FULL-AUTO AIR CONDITIONER (E)].)

3

INSPECT DASH-ELECTRICAL SUPPLY UNIT CONNECTOR FOR MALFUNCTION

•  Inspect the applicable connector and terminal.
(See CONNECTOR INSPECTION.)

•  Are the connector and terminal normal?

Yes

Go to the next step.

No

Repair or replace the malfunctioning location and perform the repair completion verification.

4

INSPECT EVAPORATOR TEMPERATURE SENSOR SIGNAL CIRCUIT AND GROUND CIRCUIT FOR OPEN CIRCUIT

•  Inspect the applicable circuit for open circuit.
(See CIRCUIT INSPECTION.)

•  Is the circuit normal?

Yes

Go to the next step.

No

Repair or replace the malfunctioning location and perform the repair completion verification.

Repair completion verification 1

VERIFY THAT VEHICLE IS REPAIRED

•  Install/connect the part removed/disconnected during the troubleshooting procedure.

•  Clear the DTC recorded in the memory.
(See CLEARING DTC.)

•  Perform the DTC inspection for the dash-electrical supply unit.
(See DTC INSPECTION.)

•  Is the same Pending DTC present?

Yes

Refer to the controller area network (CAN) malfunction diagnosis flow to inspect for a CAN communication error.

(See CONTROLLER AREA NETWORK (CAN) MALFUNCTION DIAGNOSIS FLOW [(E)].)

If the CAN communication is normal, perform the diagnosis from Step 1.

•  If the malfunction recurs, replace the dash-electrical supply unit, then go to the next step.
(See DASH-ELECTRICAL SUPPLY UNIT REMOVAL/INSTALLATION [MANUAL AIR CONDITIONER (E)].)

(See DASH-ELECTRICAL SUPPLY UNIT REMOVAL/INSTALLATION [FULL-AUTO AIR CONDITIONER (E)].)

No

Go to the next step.

Repair completion verification 2

VERIFY IF OTHER DTCs DISPLAYED

•  Perform the DTC inspection.
(See DTC INSPECTION.)

•  Are any DTCs displayed?

Yes

Repair the malfunctioning location according to the applicable DTC troubleshooting.

No

DTC troubleshooting completed.

Step	Inspection	Results	Action
1	INSPECT EVAPORATOR TEMPERATURE SENSOR CONNECTOR FOR MALFUNCTION • Inspect the applicable connector and terminal. (See CONNECTOR INSPECTION.) • Are the connector and terminal normal?	Yes	Go to the next step.
1		No	Repair or replace the malfunctioning location and perform the repair completion verification.
2	INSPECT EVAPORATOR TEMPERATURE SENSOR FOR MALFUNCTION • Inspect the applicable part. (See EVAPORATOR TEMPERATURE SENSOR INSPECTION [MANUAL AIR CONDITIONER].) (See EVAPORATOR TEMPERATURE SENSOR INSPECTION [FULL-AUTO AIR CONDITIONER].) • Is the part normal?	Yes	Go to the next step.
2		No	Repair or replace the malfunctioning location and perform the repair completion verification. (See EVAPORATOR TEMPERATURE SENSOR REMOVAL/INSTALLATION [MANUAL AIR CONDITIONER (E)].) (See EVAPORATOR TEMPERATURE SENSOR REMOVAL/INSTALLATION [FULL-AUTO AIR CONDITIONER (E)].)
3	INSPECT DASH-ELECTRICAL SUPPLY UNIT CONNECTOR FOR MALFUNCTION • Inspect the applicable connector and terminal. (See CONNECTOR INSPECTION.) • Are the connector and terminal normal?	Yes	Go to the next step.
3		No	Repair or replace the malfunctioning location and perform the repair completion verification.
4	INSPECT EVAPORATOR TEMPERATURE SENSOR SIGNAL CIRCUIT AND GROUND CIRCUIT FOR OPEN CIRCUIT • Inspect the applicable circuit for open circuit. (See CIRCUIT INSPECTION.) • Is the circuit normal?	Yes	Go to the next step.
4		No	Repair or replace the malfunctioning location and perform the repair completion verification.
Repair completion verification 1	VERIFY THAT VEHICLE IS REPAIRED • Install/connect the part removed/disconnected during the troubleshooting procedure. • Clear the DTC recorded in the memory. (See CLEARING DTC.) • Perform the DTC inspection for the dash-electrical supply unit. (See DTC INSPECTION.) • Is the same Pending DTC present?	Yes	Refer to the controller area network (CAN) malfunction diagnosis flow to inspect for a CAN communication error. (See CONTROLLER AREA NETWORK (CAN) MALFUNCTION DIAGNOSIS FLOW [(E)].) If the CAN communication is normal, perform the diagnosis from Step 1. • If the malfunction recurs, replace the dash-electrical supply unit, then go to the next step. (See DASH-ELECTRICAL SUPPLY UNIT REMOVAL/INSTALLATION [MANUAL AIR CONDITIONER (E)].) (See DASH-ELECTRICAL SUPPLY UNIT REMOVAL/INSTALLATION [FULL-AUTO AIR CONDITIONER (E)].)
Repair completion verification 1		No	Go to the next step.
Repair completion verification 2	VERIFY IF OTHER DTCs DISPLAYED • Perform the DTC inspection. (See DTC INSPECTION.) • Are any DTCs displayed?	Yes	Repair the malfunctioning location according to the applicable DTC troubleshooting.
Repair completion verification 2		No	DTC troubleshooting completed.