B1512

DTC B1512: Air Flow Control Actuator (Position Sensor) and/or Its Circuit Malfunction

Wiring Diagram










DTC Detecting Condition and Trouble Area






DTC Troubleshooting

NOTE:

- When DTC B1502, B1503, B1504 and B1511 are indicated together, it is possible that sensor ground circuit is open.
- When DTC B1511 is indicated together, it is possible that position sensor power supply circuit is open.



1.
Was "Air Conditioning System Check" performed?
YES
Go to Step 2.
NO
Go to Air Conditioning System Check:Auto A/C.

2. Wire harness check

Turn ignition switch to OFF position.
Disconnect connectors from air flow control actuator and HVAC control module.
Check for proper connection to position sensor power supply, signal and ground circuit terminals of air flow control actuator and HVAC control module connectors.
If OK, check that position sensor of air flow control actuator circuit is as follows.
- Wiring harness resistance of each position sensor power supply, signal and ground circuit is less than 3 ohms
- Insulation resistance of each position sensor power supply, signal and ground circuit is infinity between air flow control actuator connector and vehicle body ground
- Circuit voltage of each position sensor power supply, signal and ground circuit is 0 - 1 V with ignition switch turned ON

Are they in good condition?
YES
Go to Step 3.
NO
Position sensor power supply, signal circuit and/or ground circuit are open, short or high resistance.

3. Position sensor of air flow control actuator power supply voltage check

Connect connector to HVAC control module with ignition switch turned OFF.
Turn ignition switch to ON position.
Measure voltage between.
- Position sensor power supply terminal and position sensor ground terminal of air flow control actuator connector
- Position sensor signal terminal and position sensor ground terminal of air flow control actuator connector

Is voltage 4.5 - 5.5 V?
YES
Go to Step 4.
NO
Go to Step 5.

4. Air flow control actuator check

Check position sensor of air flow control actuator for performance referring to Circuit Inspection Air Flow Control Actuator and Its Circuit Inspection:Auto A/C.

Is it in good condition?
YES
Substitute a known-good HVAC control module and recheck.
NO
Replace air flow control actuator.

5. Position sensor of air flow control actuator power supply voltage check

Turn ignition switch to OFF position.
Disconnect connector from temperature control actuator.
Turn ignition switch to ON position.
Measure voltage between.
- Position sensor power supply terminal and position sensor ground terminal of air flow control actuator connector
- Position sensor signal terminal and position sensor ground terminal of air flow control actuator connector

Is voltage 4.5 - 5.5 V?
YES
Check temperature control actuator and its circuit.
NO
Substitute a known-good HVAC control module and recheck.