DTC B13AB:12, B13AB:13 [CLIMATE CONTROL UNIT (FULL-AUTO AIR CONDITIONER)]

id0702k2210400

System malfunction location	• B13AB:12: Rear air mix actuator (potentiometer) circuit short to power supply • B13AB:13: Rear air mix actuator (potentiometer) circuit open
Detection condition	• Malfunction in wiring harness between rear air mix actuator and rear climate control unit
Fail-safe function	Malfunction determined when ignition switched ON • Rear air mix actuator drive signal is stopped right when the malfunction is determined. ? However, fixed at MAX COLD when set temperature is at 15.0 °C (60 °F) and fixed at MAX HOT when set temperature is at 29.0 °C (84 °F) Malfunction already exists when ignition switched ON • Control based on ambient temperature. ? However, fixed at MAX COLD when set temperature is at 15.0 °C (60 °F) and fixed at MAX HOT when set temperature is at 29.0 °C (84 °F)
Possible cause	• Connector or terminal malfunction • Rear air mix actuator malfunction • Open circuit in wiring harness between rear climate control unit and rear air mix actuator • Short to power supply in wiring harness between rear climate control unit and rear air mix actuator • Rear climate control unit malfunction

Diagnostic Procedure

STEP	INSPECTION		ACTION
1	INSPECT REAR AIR MIX ACTUATOR CONNECTOR • Switch the ignition off. • Disconnect the negative battery terminal. (See NEGATIVE BATTERY TERMINAL DISCONNECTION/CONNECTION.) • Disconnect the rear air mix actuator connector. (See REAR AIR MIX ACTUATOR REMOVAL/INSTALLATION.) • Inspect the connector and terminals (corrosion, damage, pin disconnection). • Are the connector and terminals normal?	Yes	Go to the next step.
1		No	Repair/replace the connector or terminal. After repair procedure, go to Step 6.
2	INSPECT REAR AIR MIX ACTUATOR • Inspect the rear air mix actuator. (See REAR AIR MIX ACTUATOR INSPECTION.) • Is it normal?	Yes	Go to the next step.
2		No	Replace the rear air mix actuator. (See REAR AIR MIX ACTUATOR REMOVAL/INSTALLATION.) Go to Step 6.
3	INSPECT REAR AIR MIX ACTUATOR (POTENTIOMETER) CIRCUIT FOR OPEN CIRCUIT • Disconnect the rear climate control unit connector. (See REAR CLIMATE CONTROL UNIT REMOVAL/INSTALLATION.) • Inspect for continuity between the following terminals (wiring harness-side): ? Rear climate control unit terminal W—rear air mix actuator terminal A ? Rear climate control unit terminal S—rear air mix actuator terminal B ? Rear climate control unit terminal O—rear air mix actuator terminal C • Is there continuity?	Yes	Go to the next step.
3		No	Refer to the wiring diagram and verify whether or not there is a common connector between rear climate control unit terminal and rear air mix actuator 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 REAR AIR MIX ACTUATOR (POTENTIOMETER) CIRCUIT FOR SHORT TO POWER SUPPLY • Connect the negative battery terminal. (See NEGATIVE BATTERY TERMINAL DISCONNECTION/CONNECTION.) • Switch the ignition ON (engine off or on). • Measure the voltage at the following terminals (wiring harness-side): ? Rear climate control unit terminal W ? Rear climate control unit terminal S ? Rear climate control unit terminal O • Is the voltage 0 V?	Yes	Go to the next step.
4		No	Refer to the wiring diagram and verify whether or not there is a common connector between rear climate control unit terminal and rear air mix actuator 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 power supply. • Repair or replace the malfunctioning part. If there is no common connector: • Repair or replace the wiring harness which has a short to power supply. Go to the next step.
5	VERIFY REAR CLIMATE CONTROL UNIT CONNECTOR CONDITION • Switch the ignition off. • Disconnect the negative battery terminal. (See NEGATIVE BATTERY TERMINAL DISCONNECTION/CONNECTION.) • Inspect the connector and terminals (corrosion, damage, pin disconnection). • Are the connector and terminals normal?	Yes	Go to the next step.
5		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. • Connect the negative battery terminal. (See NEGATIVE BATTERY TERMINAL DISCONNECTION/CONNECTION.) • Clear the DTC from the climate control unit memory using the M-MDS. (See CLEARING DTC [CLIMATE CONTROL UNIT (FULL-AUTO AIR CONDITIONER)].) • Perform the DTC inspection for the climate control unit using the M-MDS. (See DTC DISPLAY [CLIMATE CONTROL UNIT (FULL-AUTO AIR CONDITIONER)].) • Is the same DTC displayed?	Yes	Repeat the inspection from Step 1. • If the malfunction recurs, replace the rear climate control unit. (See REAR CLIMATE CONTROL UNIT REMOVAL/INSTALLATION.) Go to the next step.
6		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. (See DTC TABLE [CLIMATE CONTROL UNIT (FULL-AUTO AIR CONDITIONER)].)
7		No	DTC troubleshooting completed.